8/8/2019 TCVN 6275_V_E

1/48

tiu chun vit nam tcvn 6275 : 2003

qui phm h thng lm lnh hng

Rules for Cargo Refrigerating Installations

Chng 1 QUI NH CHUNG

1.1 Qui nh chung

1.1.1 Phm vi p dng

1 Qui phm v h thng lm lnh hng trn tu thy (sau y c gi l "Qui phm") p dng cho vic kimtra v ch to h thng lm lnh hng v cc h thng ph tr gm c h thng iu chnh thnh phn khngkh (sau y c gi l "h thng lm lnh") ca cc tu hoc s c ng kim Vit nam (sau y gi lng kim) phn cp v tun theo Chng 2, Phn 1A caTCVN 6259 : 2003 "Qui phm phn cp v ngtu bin v thp".

2 i vi cc thit b ca h thng lm lnh c nu -1, cc yu cu trong Qui phm ny p dng cho cc hthng lm lnh s dng cc cng cht lm lnh s cp (chnh) c nu di y. Vic kim tra v ch to hthng lm lnh dng cc cng cht lm lnh s cp khc vi cc cht lm lnh c nu di y phi cng kim cho l ph hp:R 22 : CHClF2R134a : CH2FCF3

R 404A: R125/R143a/R134a ( 44/52/4 % trng lng) CHF2CF3/ CH3CF3/ CH2FCF3 R 407C: R32/R125/R134a (23/25/52 % trng lng) CH2F2 / CHF2CF3 / CH2FCF3 R 410A: R32/R125 (50/50 % trng lng) CH2F2 / CHF2CF

R507A : R125/ R143a (48,8/ 51,2 % trng lng) CHF2ClF3 / CH3F 2CF3R717 : Amnic (NH3)

3 i vi cc h thng lm lnh ca tu c vng hot ng hn ch hoc sc cha nh, mt s qui nh trongQui phm ny c th c sa i cho thch hp vi iu kin l ng kim xem xt tha ng.

4 Theo yu cu ca Ch tu hoc i din ca Ch tu, ng kim c th kim tra vic xp hng ln tu c hthng lm lnh ng k ti cng xp hng ph hp vi cc qui nh Chng 7 ca Qui phm ny. Khihon thnh kim tra vi s ng ca ng kim vin, giy chng nhn v kim tra xp hng ln tu s ccp cho tu.

5 Kim tra v ch to h thng iu chnh thnh phn khng kh c nu -1 trn phi c ng kim xem

xt thch ng.6 Cc yu cu lin quan ca Qui phm phn cp v ng tu bin v thp, TCVN 6259 : 2003 cng p dng i

vi vt liu, trang thit b, vic lp t h thng v tay ngh cng nhn, tr khi c Qui ph m qui nh khci.

1.1.2 Cc h thng c bit

Kim tra v ch to h thng lm lnh m cc qui nh trong phn ny khng th p dng ngay c v l doring phi c ng kim xem xt thch ng.

1.1.3 Thay th tng ng

Cc h thng lm lnh khng tun th cc qui nh ca Qui phm ny c th c chp thun vi iu kin lchng phi c ng kim cho l tng ng vi cc qui nh trong Qui phm ny.

7

8/8/2019 TCVN 6275_V_E

2/48

tcvn 6275 : 2003, Chng 1

1.1.4 K hiu ng k

1 Cc h thng lm lnh c ng k ph hp vi Qui phm (khng k h thng c nu -2 sau y) s cphn bit theo cc k hiu RMC* hay RMC.

2 Cc h thng lm lnh c trang b h thng kim sot thnh phn khng kh c ng k ph hp vi Quiphm ny s c phn bit bng cc k hiu RMC*.CA hoc RMC.CA.

1.1.5 Cc ghi ch

1 Thng thng phi ghi nhit thp nht trong bung lnh c duy tr nhit nc bin cao nht vo sauk hiu ng k.V d : -25oC/ 32oC i vi bung lnh loi A, B v C v

-15oC/ 32oC i vi bung lnh loi D v E.

Ch thch : -25oC hay -15oC l nhit thp nht phi c duy tr trong bung;

32oC l nhit cao nht ca nc bin.

2 Khi h thng c trang b thm cc thit b ph gip cho vic chuyn ch cc loi hng ha c bit hocmy lm ng nhanh cc tu c, cc du hiu ph hp phi c thm vo k hiu ng k ty theo n ngh ca Ch tu.

V d : c trang b ch rau qu

c trang b my lm ng nhanh.

3 Khi h thng c thit b sinh kh nit (N2) c nh l mt phn ca h thng kim sot thnh phn khng kh,phi thm vo k hiu ng k ghi ch sau:

c trang b thit b sinh kh nit c nh.

4 Khi h thng kim sot thnh phn khng kh c lp t ch cho cc khoang hng no , cc ghi ch thchhp phi c thm vo.

V d : c trang b cho khoang hng No.F v No.G.

5 Khi ng kim xt thy cn thit phn bit v m t cc c im ring bit hoc gii h n ng dng hthng, cc du hiu phn bit thch hp khc vi nu t-1 n -4 trn s c a vo k hiu ng k.

1.2 Cc nh ngha

Nu khng c qui nh no khc, cc thut ng dng trong Qui phm ny c nh ngha nh (1) n (7)di y.

(1) "H thng lm lnh" c ngha l thit b lm lnh, cch nhit cho cc bung lnh, cc thit b c lin quankhc trong bung lnh v h thng kim sot thnh phn khng kh c ng k.

(2) "Thit b lm lnh" l mt t hp cc my lm lnh to thnh chu trnh lm lnh bao gm cc my nnkh, bu ngng, bnh cha, dn bay hi, bu sinh hn, h thng ng v ph tng ng ng, cc ng c

dn ng my nn kh v cc bm cht lm lnh, v cc thit b in.(3) "My lm lnh" c ngha chung l cc my cn thit vn hnh cc chu trnh lnh gia cc thit b lm

lnh nh l cc my nn, m-t, bu ngng, bnh cha, dn bay hi, bm, v.v...(4) "Nc mui" l mt thut ng chung ch cc cng cht lm l nh th cp (mi cht). N c lm lnh

bng cht lm lnh s cp v n l mi cht lm lnh hng ha.(5) "p sut thit k" l p sut ln nht c nh ch to tnh ton thit k. Tuy nhin, p sut thit k phi

khng nh hn gi tr c qui nh Bng1.1, ty theo tng loi cng cht.(6) "H thng kim sot thnh phn khng kh" l h thng iu chnh v duy tr hm lng xi mc thp

trong cc khoang hng bng cch a kh nit vo ko di s ti sng ca hng ha. H thng nyc xem nh l h thng ph tr cho h thng lm lnh.

(7) Ngy n nh kim tra hng nm (Anniversary Date) l ngy tng ng vi ngy ht hn ca Giy chngnhn phn cp nhng khng bao gm chnh ngy ht hn .

8

8/8/2019 TCVN 6275_V_E

3/48

tcvn 6275 : 2003, Chng 1

Bng 1.1 p sut thit k thp nht

Cng cht lm lnh R22 R134a R404a R407C R410A R507A R717

p sut thit k

PhaAC (1) 1,9 1.4 2,5 2,4 3,3 2,5 2,3

thp nht(MPa)

PhaAT(2) 1,5 1,1 2,0 1.9 2,6 2,0 1,8

Ch thch :(1) PhaAC (p sut cao) l phn p sut t ca ra ca my nn n van tit lu.(2) PhaAT (p sut thp) l phn p sut t van tit lu n ca ht ca my nn,

h thng nn nhiu cp th l phn p sut t ca ra ca cp thp p n ca ht ca cp cao p.

9

8/8/2019 TCVN 6275_V_E

4/48

tcvn 6275 : 2003, Chng 2

Chng 2 KIM TRA

2.1 Qui nh chung

2.1.1 Cc dng kim tra

(1) Kim tra ng k (kim tra ln u)Kim tra ng k bao gm cc kim tra sau:(a) Kim tra ng k trong qu trnh ch to h thng(b) Kim tra ng k h thng c ch to khng c s gim st ca ng kim

(2) Kim tra duy tr ng k (kim tra chu k)Kim tra duy tr ng k bao gm cc kim tra sau:(a) Kim tra nh k(b) Kim tra hng nm(c) Kim tra bt thng

2.1.2 Kim tra ng k v thi hn ca cc t kim tra chu k1 Kim tra ng k

(1) Kim tra ng k trong qu trnh ch to h thng c ng k, cc h thng lm lnh phi c ng kim kim tra ng k. Trong t kim tra ny,ng kim vin phi gim st vic ch to theo thit k duyt. Cc giai on cng vic sau y phi schng kin ca ng kim vin. Tuy nhin, tr trng hp th cn bng nhit c nu 6.2.6, cc quinh c th c thay i khi xt n tnh trng thc t ca thit b, kh nng k thut v vic kim sotcht lng ca nh my ch to.(a) Khi tin hnh th vt liu theo cc qui nh Phn 7 ca TCVN 6259 : 2003 "Qui phm phn cp v

ng tu bin v thp v cc cng vic th cn thit khc cng nhn hoc chp nhn c nu

3.1.3-4, 5.2.1-1 v 5.2.5 ca Qui phm ny.(b) Khi c cc vn lin quan n vt liu c dng ring cho cc chi tit hoc lin quan n cc chitit c dng ring cho cc h thng lm lnh.

(c) Khi hon thnh cc chi tit quan trng, v nu cn thit, mt thi im thch hp trong qu trnh chto.

(d) Khi tin hnh cc th nghim c nu Chng 6.(2) Kim tra ng k h thng c ch to khng c s gim st ca ng kim

H thng lm lnh c ch to khng c s gim st ca ng kim nu mun c ng k phi c n ngh v phi c ng kim kim tra ng k.

2 Kim tra duy tr ng kH thng lm lnh c ng k phi chu s kim tra theo chu k nh nu di y duy tr ng k ca

chng:

(1) Cc t kim tra nh k phi c tin hnh vo nhng khong thi gian c qui nh 1.1.3-1(4), Phn1B caTCVN 6259 : 2003Qui phm phn cp v ng tu bin v thp.

(2) Cc t kim tra hng nm phi c tin hnh vo nhng khong thi gian c qui nh 1.1.3-1(1),Phn 1B ca TCVN 6259 : 2003 Qui phm phn cp v ng tu bin v thp.

(3) Kim tra bt thng:Kim tra bt thng c thc hin vo mt trong cc thi im c nu t (a) n (d) di y, khngph thuc vo cc t kim tra nh k hoc kim tra hng nm:(a) Khi cc b phn chnh ca h thng b h hng, c sa cha hoc c thay mi;(b) Khi cc h thng c sa i hoc hon ci;

(c) Khi ng kim xt thy cn thit phi sa cha mt b phn quan trng no ca h thng t i thiim khng phi l t kim tra nh k hoc t kim tra hng nm;

(d) Khi c nhu cu kim tra v cc mc ch khc.

10

8/8/2019 TCVN 6275_V_E

5/48

tcvn 6275 : 2003, Chng 2

2.1.3 Thc hin kim tra nh k v kim tra hng nm trc thi hn, v.v...

1 Thc hin kim tra trc thi hnCc yu cu cho vic thc hin kim tra nh k v kim tra hng nm trc thi hn phi ph hp vi cc qui

nh c nu 1.1.4, Phn 1B ca TCVN 6259 : 2003, Qui phm phn cp v ng tu bin v thp.2 Hon kim tra nh k

Cc yu cu cho vic tr hon kim tra nh k phi ph hp vi cc qui nh c nu 1.1.5-1(1) hay 1.1.5-1(2), Phn 1B ca TCVN 6259 : 2003 Qui phm phn cp v ng tu bin v thp.

3 Hy b kim tra tng phnTi t kim tra nh k, ty theo s suy xt ca mnh, ng kim vin c th khng cn thc hin vic kimtra i vi hng mc c kim tra tha mn vi cc yu cu ca t kim tra nh k ti t kim tra hngnm hoc kim tra bt thng trc .

4 Thay iTi t kim tra nh k, ng kim vin c th thay i cc yu cu i vi h thng lm lnh hng c qui

nh 2.3.1-1, khi xt n kch c, mc ch, kt cu, qu trnh hot ng, kt qu ca t kim tra trc vtnh trng hin thi ca h thng.

5 Kim tra lin tc

(1) i vi cc my mc v trang thit b c ng kim chp thun cho lp xung tu, nu chng ckim tra lun phin u n p ng tt c cc yu cu ca kim tra nh k trong vng 5 nm vkhong thi gian gia cc t kim tra k tip nhau cho mi thit b khng qu 5 nm, th c th thay ivic kim tra cc thit b ny mt cch thch hp ty theo s suy xt ca ng kim vin.

(2) Vic kim tra theo cch c nu (1) trn c gi l kim tra lin tc.

2.1.4 Chun b cho vic kim tra v cc yu cu khc

1 Ch tu hoc i din ca Ch tu phi thc hin tt c cc cng vic chun b cn thit cho vic kim tracng nh cc cng vic chun b khc, nu ng kim vin thy cn thit, ph hp vi cc yu cu ca Quiphm. Cc cng vic chun b phi bao gm vic thit lp cc li vo v tr kim tra thun tin v an ton,chun b cc phng tin, bin bn cn thit cho vic thc hin kim tra. Cc trang b kim tra, o c vth nghim m ng kim vin da vo a ra cc quyt nh c nh hng n vic phn cp, phi cdu hiu nhn dng ring bit v c kim chun theo mt tiu chun m ng kim cho l ph hp. Tuynhin, ng kim vin c th chp nhn cc dng c o n gin (v d: thc thng, thc dy, dng c okim tra kch thc mi hn, pan-me) m khng cn c nhn dng ring bit hay xc nhn kim chun,min l cc dng c o ny thuc kiu thit k thng dng, c bo dng mt cch thch hp v nh k sosnh vi cc thit b tng t khc hoc cc mu th. ng kim vin cng c th chp nhn cc thit b o

c lp t o c, gim st cc trang thit b trn tu (v d cc dng c o p sut, nhit , vng quay)da trn cc bin bn kim chun (trc y) hoc bng cch so snh cc ch s o c vi cc dng c ovn nng.

2 Ch tu hoc i din ca Ch tu phi b tr mt nhn vin c hiu bit k cng v cc h ng mc s kim tra thc hin cng tc chun b cho vic kim tra nhm to ra s tr gip cn thit cho ng kim vin, theoyu cu ca anh ta, trong sut qu trnh kim tra.

3 C th tr hon t kim tra khi:

(1) Cc cng vic chun b cn thit cha c hon thnh hoc khng c thc hin;(2) Khng c mt bt k mt nhn vin tr gip kim tra no, nh c nu -2 trn;(3) ng kim vin cho rng khng m bo an ton cho vic tin hnh kim tra.

11

8/8/2019 TCVN 6275_V_E

6/48

tcvn 6275 : 2003, Chng 2

4 Sau khi kim tra, nu thy cn thit phi thc hin cc cng vic sa cha no , ng kim vin s thngbo cc khuyn ngh ca mnh cho ngi yu cu kim tra bit. Da vo , cc cng vic sa cha phi cthc hin p ng cc yu cu ca ng kim vin.

2.2 Kim tra ng k

2.2.1 Kim tra ng k trong qu trnh ch to

1 Khi kim tra ng k trong qu trnh ch to, phi xem xt t m kt cu, vt liu, tiu chun kch thc v chtlng ca h thng lm lnh xc nh c rng chng tha mn cc qui nh c lin quan trong ccChng ca Qui phm ny.

2 Cc thit b lm lnh c dng trong h thng lm lnh mun c ng kim ng k c th c chpnhn khng cn cc th nghim theo yu cu ca chng bng vic cng nhn Giy chng nhn c ngkim cp.

3 i vi h thng lm lnh mun c kim tra ng k trong qu trnh ch to, trc khi bt u cng vic

phi trnh cho ng kim ba bn sao cc h s v ti liu nu di y:

(1) c im k thut ca h thng lm lnh (bao gm c im ca cc n v lm lnh);(2) Cc bn tnh nhit;(3) B tr chung thit b lm lnh (gm c b tr thng gi chi tit);(4) Bn v mt ct ca my nn cht lm lnh v bn v chi tit (c ghi r vt liu) ca trc khuu my nn

kiu pit tng hoc rto ca my nn kiu trc vt, hoc rto, a v v bao ca my nn kiu tua bin vbn v ca c cu tng tc;

(5) Bn v chi tit ca bnh chu p lc chu p sut ca cht lm lnh s cp (bu ngng, bnh cha, thit bbc hi (thit b lm lnh nc mui), thit b phn ly du, kt xung lc, b lm lnh trung gian, ...);

(6) B tr ng ng dn cht lm lnh s cp v th cp v nc lm mt (nu r vt liu, ng knh v

chiu dy ca ng);(7) B tr bung lnh (gm c ng tun hon khng kh v thng gi);(8) S mng in ca h thng lm lnh v b tr cc thit b in;(9) S mng in trong bung lnh (gm c cc chi tit kt cu xuyn qua lp cch nhit);(10) Loi cch nhit trn tt c cc b mt, tnh cht vt l, dy v phng php g lp lp cch nhit v

lp lt (gm c cc chi tit kt cu v phng php cch nhit hm hng, ca vo, ng thng gi, cc lthot nc);

(11) Thit b x v thit b kh tuyt trong bung lnh v cc khoang trong lp t thit b lm lnh khngkh;

(12) B tr nhit k hoc b cm bin trong bung lnh v thit b lm lnh khng kh v phi cho bit tn caNh ch to v kiu ca b cm bin;

(13) Ti liu ch dn trnh by chc nng ca s iu chnh nhit t ng;(14) Th cn bng nhit v s o (biu c tnh ca my nn, qut v cc ng c dn ng cng phic trnh);

(15) Cc ti liu cp n v tr (s dng) v cc thng tin chi tit khc ca cc vt liu c cha aming, nucc vt liu c dng.

(16) Cc ti liu khc khi ng kim thy cn thit.

4 Bt k cc yu cu -3, mt s bn v v ti liu c nu -3 c th c min trnh trong trng hp khi hthng lm lnh c d nh sn sut ti cng mt xng ca hng ch to trn c s cc bn v v ti liu c ng kim duyt.

2.2.2 Kim tra ng k h thng c ch to khng c s gim st ca ng kim

1 Qui nh chung

Khi kim tra ng k h thng c ch to khng c s gim st ca ng kim, h thng lm lnh phi

12

8/8/2019 TCVN 6275_V_E

7/48

tcvn 6275 : 2003, Chng 2

c xem xt v cu to, vt liu, cht lng v trng thi hin ti ca chng nh qui nh i vi kim tranh k tng ng vi tui ca chng xc nh cht lng ca h thng.

2 Th

Khi kim tra ng k h thng c ch to khng c s gim st lp t, vic th hot ng v cc th

nghim khc phi c thc hin ph hp vi cc qui nh Chng 6. Tuy nhin, s th cn bng nhit cth thay th bng s th khc hoc c min th nu c ng kim vin chp thun.

3 H thng lm lnh c ch to khng c s gim st ca ng kim, khi kim tra ng k c th phi trnhng kim cc ti liu v bn v nh qui nh 2.2.1.

2.3 Kim tra chu k

2.3.1 Kim tra nh k

1 kim tra nh k, phi thc hin cc kim tra c nu (1) n (18) di y :

(1) Kim tra s nht k ca h thng lm lnh nm c trng thi hot ng ca h thng trong qu trnhkhai thc.

(2) Phi kim tra cc lp bc cch nhit v s c nh chng. Bt k s ch bo m hoc h hng cchnhit no u phi c nghin cu tm hiu.

(3) Phi kim tra cc ng tun hon khng kh, cc np hm v m kn ca chng, cc ca vo v s ngcht ca chng, cc h thng thng gi v cc phng tin ng kn chng. Phi ch n tr ng thi ccphn m cc ng thng gi xuyn qua tn boong.

(4) Cc l x, ging, bu lc, ng ht v ng o nc y tu, cc ng thot nc cng vi cc van chn mtchiu v cc ng ch U (xi phng) kn nc c lp vi chng phi c lm s ch v kim tra. Thit bkh tuyt ca b lm lnh khng kh v thit b x ca chng cng phi c kim tra.

(5) Phi kim tra trng thi ca cc ng xon lm lnh ca b lm lnh khng kh, cc li lm lnh (gm cnc mui) trong cc bung lnh.

(6) Thn bu ngng, bnh cha, b bc hi, b phn ly, thit b sy, b lc v cc bnh chu p lc khc chutc dng p sut ca cht lm lnh s cp v cc mi ni ca chng v ng ng dn phi c kim trabn ngoi n mc c th thc hin c.

(7) Phi kim tra m v h hng ca cch nhit trn cc b mt ca cc bnh chu p lc, cc u ni ngv ng dn.

(8) Cc my nn kiu pt tng cng vi h thng bi trn ca chng phi c m ra v kim tra. i vitrng hp my nn kiu trc vt hoc cc my nn c ng kim cho l thch hp, khong thi gianm (my nn) c th c ng kim thay i vi iu kin trng thi lm vic ca chng c thy ltha mn.

(9) Cc bm nc lm mt bu ngng, cc bm cht lm lnh s cp v cc bm nc mui phi c m rav kim tra.

(10) Cc ng ng dn cht lm lnh c cch nhit phi c kim tra c bn ngoi v bn trong ccbung c cch ly, tho lp cch nhit mc cn thit kim tra trng thi ca chng, c bit cc ch ng c ni bng hn i u hoc cc mi ni ren.

(11) Tt c cc van gim p trn ton b h thng lm lnh phi c iu chnh v p sut cn bng cachng.

(12) Tt c cc c cu iu khin t ng, thit b an ton v tn hiu bo ng u phi c th chc nngy ca chng.

(13) Phi kim tra chnh xc ca cc nhit k v dng c c chn xc sut dng o nhit trong ccbung v khng kh dng ht v dng cung cp chnh. ng kim vin c th chp nhn bin bn kimtra do nhng ngi tin cy lm.

(14) Phi xem xt cn thn cch nhit trong cc bung lnh, v khi thy cn thit phi khoan xc nh snguyn vn v kh ro ca lp cch nhit, sau cc l khoan kim tra phi c bt kn li cn thn.(15) H thng ng dn nc mui phi c th vi p sut bng 1,5 ln p sut thit k hoc bng 0,4MPa,

th theo p sut no ln hn.

13

8/8/2019 TCVN 6275_V_E

8/48

tcvn 6275 : 2003, Chng 2

(16) Cc bnh chu p lc phi c m ra kim tra, v sau c th p lc nh sau:(a) ng xon ca bu ngng kh kiu ng xon trong hp phi c kim tra v th n p lc 1,5 ln p

sut thit k ca pha cao p. Khi khng th tho ng xon ra c c th kim tra qua ca kim tra(ca bu ngng) v th ti ch.

(b) ng xon ca bu bc hi kiu ng xon trong hp phi c kim tra v th n p lc 1,5 ln p

sut thit k ca pha thp p. Khi khng th tho ng xon ra c c th kim tra qua ca kim tra(ca bu bc hi) v th ti ch.

(c) Bu ngng kh kiu ng bc ng (shell-and-tube type) v bu bc hi kh (thit b lm l nh ncmui) kiu ng bc ng trong cht lm lnh s cp trong ng bc th phi tho cc np u ngnc hoc nc mui v mt sng ng v kim tra u cc ng v pha trong np u ng. Sau phn ng bc phi c th n p lc bng p sut thit k ca pha cao p.

(d) B bc hi kh (thit b lm lnh nc mui) kiu ng bc ng trong nc mui trong ng bcth cc np u ng cht lm lnh s cp phi c tho ra v kim tra cc u ng v bn trong npu ng. Phn ng bc phi c th n p lc bng 1,5 ln p sut thit k hoc bng 0,4 MPa, ththeo p lc no ln hn. Sau khi lp li np u ng, pha cht lm lnh s cp phi c th n plc bng p sut thit k ca pha thp p.

(e) Cc bnh cha cht lm lnh s cp phi c th thy lc p sut thit k ca pha cao p. Tuynhin, khi cc bnh cha c thit k s dng cc cng cht lm lnh s cp nh R22, R134a,R404A, R407C, R410A, hoc R507A , hoc khi chng c kim tra bng phng php th siu mhoc cc phng php kim tra khng ph hy c hiu qu khc m khng c khuyt tt c hi nh bn mn hoc nt trn b mt bn trong ca bnh, vic th p p lc ni trn c th c bi b.

(f) i vi cc bnh p lc cha cc cng cht lm lnh R22, R134a, R404A, R407C, R 410A hocR507A, vic th p lc c qui nh t (a) n (e) nu trn c th b qua vi iu kin cc bnh nyc thy tnh trng tt.

(17) Phi kim nghim trng thi hin ti ca thit b in v cp in. Chng phi c xc nh rng in trcch in ca chng khng di 100.000 gia cc mch c cch in v tip t. Khi vic ghi chpchnh xc c duy tr, ng kim vin c th cho php b vic kim nghim ni trn.

(18) Phi tin hnh th hot ng ca h thng lm lnh.

2.3.2 Kim tra hng nm

Khikim tra hng nm, phi tin hnh xem xt k bn ngoi cc hng mc nu (1) n (5) di y. Cngc th thc hin xem xt k cc hng mc m chng c chun b kim tra chi tit hoc chng cm ra theo s la chn ca Ch tu. Nu c bt k khuyt tt no c pht hin cc kim tra , ng kimvin c th yu cu m ra xem xt k cc hng mc c nghi ng.(1) Phi kim tra cc hng mc c qui nh (1) n (7) v (13) 2.3.1.(2) Cc my nn, bm nc lm mt bu ngng, bm cht lm lnh s cp, bm nc mui, qut tun hon

khng kh v cc ng c dn ng chng phi c kim tra bn ngoi.

(3) Phi kim tra bn ngoi v s n mn cc np u ng nc ca bu ngng c ng kim vin la chnqua cc ca kim tra hoc cc l khot thch hp khc trn bu ngng.

(4) Phi kim tra in tr ca cc ng c v thit b iu khin cc my nn, bm, qut, ... v dy dn cachng, v in tr ny phi khng di 100.000 gia mch cch in v ni t.Tuy nhin, khi s ghi chp chnh xc c duy tr, ng kim vin c th cho php b vic th ny.

(5) Phi thc hin th xc sut xc nh rng thit b iu khin t ng, thit b an ton v bo hiu l trong trng thi tt.

2.3.3 Kim tra bt thng

Khikim tra bt thng, vic xem xt hoc th cc hng mc yu cu phi c tin hnh ph hp vi cc quinh 2.1.2-2(3).

14

8/8/2019 TCVN 6275_V_E

9/48

tcvn 6275 : 2003, Chng 3

Chng 3 thit b lm lnh

3.1 Qui nh chung

3.1.1 Qui nh chung

1 Thit b lm lnh phi c thit k c tnh n mc ch s dng v iu kin khai thc chng.

2 Tt c cc b phn ca thit b lm lnh phi c ch to v b tr sao cho chng c th d dng cho bodng v tho ra sa cha hoc thay th.

3 Khi dng cht lm lnh R717, thit b lm lnh phi tha mn cc yu cu ca Chng ny v ngoi ra cnphi tha mn cc yu cu ca Chng 4.

4 Cc ng dng cho cng cht lm lnh s cp R22, R134a, R404A, R407C, R410A hoc R507A phi cphn vo ng Nhm III qui nh 12.1.3, Phn 3 ca TCVN 6259 : 2003 "Qui phm phn cp v ng tubin v thp".

5 Cc bnh chu p lc cha cc cng cht lm lnh R22, R134a, R404A, R407C, R410A hoc R507A phic phn loi ph hp vi cc yu cu 10.1.3, Phn 3 caTCVN 6259 : 2003 Qui phm phn cp v ngtu bin v thp, ty theo p sut thit k qui nh 1.2(5) ca Qui phm ny.

6 Thit b lm lnh phi trang b cc dng c sau y:

(1) Nhit k tiu chun: 2 b(2) T trng k: 1 b (trong trng hp lm lnh nc mui)(3) Thit b pht hin (hi) cht lm lnh r lt : 1 b

3.1.2 Sn lng v s lng thit b lm lnh

1 Phi trang b t nht hai n v lm lnh (thng thng gm c mt my nn v ng c lai n, mt bungng, mt dn bay hi, mt bm v cc ph tng khc cn thit cho thit b hot ng mt cch c lp) vb tr sao cho thay th nhau mt cch d dng.

2 Sn lng lm lnh ca h thng phi duy tr nhit ca cc bung l nh c ch du hiu m t bsung k hiu phn cp, vi bt k mt n v lm lnh no b ngng lm vic.

3.1.3 Vt liu v hn

1 Vt liu dng cho thit b lm lnh phi thch hp vi cht lm lnh c s dng, p sut thit k, nhit lm vic thp nht, v.v....

2 Vt liu dng lm ng dn cng cht lm lnh s cp, cc van v cc ph tng ca chng phi ph hp vi cc

yu cu c nu t12.1.4 n 12.1.6, Phn 3 caTCVN 6259 : 2003, Qui phm phn cp v ng tu binv thp, ty theo tng loi ng c qui nh 3.1.1-4 v 4.2.1-1.

3 Vt liu dng ch to cc bnh chu p lc tip xc trc tip vi cng cht lm lnh cao p (cc bu ngng,bnh cha lng v cc bnh chu p lc khc) phi ph hp vi cc yu cu nu 10.2, Phn 3 ca TCVN6259 : 2003, Qui phm phn cp v ng tu bin v thp, ty theo loi ca bnh p lc c qui nh 3.1.1-5 v 4.2.1-1.

4 Khng c s dng cc vt liu c lit k di y :

(1) Hp kim nhm cha trn 2% Magi i vi cc b phn tip xc vi cc Freon .(2) Nhm tinh khit di 99,7% i vi cc b phn tip xc vi nc (tr vt liu c x l bo v chng

n mn).

5 Vic dng cc van lm bng gang phi ph hp vi qui nh Bng3.1. Ngay c khi trong bng cho phpdng cc van bng gang th cc van cng khng c s dng ni c nhit thit k di 0oC hoc cao

15

8/8/2019 TCVN 6275_V_E

10/48

tcvn 6275 : 2003, Chng 3

hn 220oC. Cc van ny vn c th c dng nhit xung thp n -50oC, nu nhit thit k nh hn00C, vi iu kin chng c s dng ch p sut n 1/2,5 (ln) p sut thit k.

6 Cc thit b lm lnh dng cc vt liu chuyn bit nh ng cao su, ng nha, ng vinyl, v.v ... hoc hp kimnhm phi c ng kim cng nhn hoc chp thun, c xt n cht lm lnh c s dng hoc iu kin

lm vic.7 Vic hn i vi thit b lm lnh phi ph hp vi cc yu cu c lin quan Chng 11, Phn 3 ca TCVN

6259 : 2003, Qui phm phn cp v ng tu bin v thp.

Bng 3.1 Gii hn s dng cc van lm bng gang

Loi van Vt liu p dng

Gang xm c gii hn bn kokhng ln hn 200 N/mm2 hoccc loi tng ng

Khng c dng

Van chnGang xm khc vi loi cnu trn, gang gra-phit mtcu, gang do hoc cc loitng ng

(1) C th dng i vi p sut thit k khng vt qu1,6MPa.

(2) C th dng i vi p sut thit k vt qu 1,6MPanhng khng qu 2,6MPa, vi iu kin ng knhdanh ngha khng qu 100mm v nhit thit kkhng ln hn 150oC

Van gim p Bt k loi gang no Khng c dng

Gang xm c gii hn bn kokhng ln hn 200 N/mm2 hoccc loi tng ng

Khng c dng

Van iukhin tng

Gang xm khc vi loi c

nu trn v cc loi tngng

(1) C th dng i vi p sut thit k khng vt qu 1,6MPa.

(2) C th dng i vi p sut thit k vt qu 1,6 MPanhng khng qu 2,6 MPa, vi iu kin ng knhdanh ngha khng qu 100 mm v nhit thit kkhng ln hn 150oC

Gang graphit mt cu, gang dohoc cc loi tng ng

Khng c dng i vi p sut thit k vt qu 3,2MPa.

3.2 Kt cu ca thit b lm lnh

3.2.1 My nn cht lm lnh1 Cc b phn my nn ty theo p sut ca cht lm lnh (gm c cc te trong v my nn kiu pt tng) phi

c thit k sao cho chu c p sut tnh ton cho pha cao p. Tuy nhin, khi cc van gim p c tcho cc te lin vi xi lanh my nn, cc b phn ni trn c th c thit k vi p sut tnh ton cho vangim p.

2 Khi my nn c bi trn bng du p lc, my nn phi t ng dng khi p lc du tt xung di gi tr nh trc.

3 My nn phi c thit b bo hiu hoc t ng ngng hot ng khi p sut nc lm mt bu ngng ttxung di gi tr nh trc.

3.2.2 My dn ng v b truyn ng

ng c lai v b tng tc ca my nn phi ph hp vi cc qui nh thch hp Phn 3 v Phn 4 ca

16

8/8/2019 TCVN 6275_V_E

11/48

tcvn 6275 : 2003, Chng 3

TCVN 6259 : 2003, Qui phm phn cp v ng tu bin v thp".

3.2.3 Cc bnh chu p lc tip xc trc tip vi cht lm lnh

Vic thit k, ch to v sc bn ca cc bnh chu p lc tip xc trc tip vi cht lm lnh (cc bu ngng,

cc bnh cha v cc bnh chu p lc khc) phi ph hp vi cc yu cu t 10.3 ti 10.8, Phn 3 ca TCVN6259 : 2003 Qui phm phn cp v ng tu bin v thp (ngoi tr cc yu cu 10.8.3).

3.2.4 Thit b phn ly du

Phi trang b thit b phn ly du thch hp cng h thng thi du cho pha x ca my nn, tr khi trang bmt thit b c t hp vi dn bay hi m bo vic thu hi du.

3.2.5 Thit b lc

Phi trang b thit b lc thch hp trn ng ng dn hi cht lm lnh n my nn v trn ng ng ncht lng n b iu chnh t ng. C th b thit b lc vi iu kin thit b phn ly du c lp c kh

nng lc.

3.2.6 Thit b sy hi (bu sy hi)

Thit b sy hi phi c trang b cho cc ng dn cht lm lnh R22, R134a, R404A, R407C, R410A hocR507A. Cc thit b sy hi phi c b tr sao cho, trong trng hp b hng hc, chng c th cho phpcng cht i tt qua hoc chuyn i sang thit b d phng m khng lm gin on hot ng ca h thnglm lnh. Tuy nhin, khng yu cu s b tr nh vy khi vic chuyn i sang thit b d phng c mbo bng mt thit b hp nht vi dn bay hi.

3.2.7 Bm cht lm lnh

Khi cht lm lnh s cp v/hoc cht lm lnh th cp c tun hon trong h thng bng bm phi trang bcc bm d phng c b tr sao cho d thay th nhau duy tr hot ng bnh thng. Lu lng ca bmd phng phi khng nh hn lu lng ca bm ln nht.

3.2.8 Cc bm nc lm mt bu ngng

1 t nht phi c 2 bm nc lm mt bu ngng ring bit v phi c b tr sao cho c th thay th ln nhau.Trong trng hp ny, mt trong cc bm c th c s dng cho mc ch khc vi iu kin lu lngv vic s dng n vo cc cng vic khc khng gy tr ngi cho s cp nc lm mt bu ngng.

2 Nc lm mt bu ngng phi c ly vo t nht t 2 u ni thng bin (ming ht). Mt trong hai u niphi c b tr mn tri v u ni kia bn mn phi.

3.2.9 H thng ng dn

1 Vic thit k, kt cu, sc bn, ch to v cc ph tng ca cc h thng ng dn phi ph hp vi cc quinh t12.2 ti 12.4 v 13.2 (ngoi tr cc qui nh 13.2.1-6) Phn 3 ca TCVN 6259 : 2003 Qui phmphn cp v ng tu bin v thp.

2 Cc ng v bch ni ng phi ph hp vi cc qui nh i vi khng kh Bng3/12.8 Chng 12, Phn 3,TCVN 6259 : 2003, "Qui phm phn cp v ng tu bin v thp".

3.2.10 Cc thit b an ton phng qu p

1 Phi lp mt thit b ngt p sut cao v mt van an ton gia mi my nn (tr cc my nn tua bin) v vanchn ti u ra ca chng. Ming x ca cc van an ton phi c dn ra khng gian h hoc dn ti phathp p ca h thng ng dn cht lm lnh.

17

8/8/2019 TCVN 6275_V_E

12/48

tcvn 6275 : 2003, Chng 3

2 Pha cht lm lnh ca bu ngng, bnh cha, v cc b phn cha cht lm lnh lng m chng c th b clp v phi chu mt p sut vt qu p sut thit k ca chng th phi c trang b van an ton (van iup) hoc cc thit b x p thch hp khc.

3 Phi trang b cc van an ton hoc cc thit b x p thch hp khc cho cc bnh chu p lc c dng cho

pha thp p cha cht lm lnh lng (gm c b lm lnh nc mui v kt nc mui kiu ng kn) vc cch ly bng van chn.

4 Tt c cc bm v cc h thng ng dn m chng c th phi chu mt p sut vt qu p sut thit k thphi c trang b van gim p hoc cc thit b gim p thch hp khc.

5 Khi x t van an ton bn pha p cao ca cht lm lnh s cp phi c dn n bn pha p thp, s b trphi sao cho hot ng ca van an ton khng b nh hng do s tch t p sut pha ngc li.

6 Khi vic x t van gim p hoc t cc thit b gim p khc c dn ra khng gian thong, cc ca phic t ti cc v tr an ton pha trn boong thi tit.

7 Cc thit b gim p phi c kh nng ngn nga s tch t p sut vt qu 1,1 ln p sut thit k ca cc b

phn c lp thit b.

3.2.11 iu khin t ng

iu khin t ng phi ph hp vi cc qui nh 18.2 Phn 3 ca TCVN 6259 : 1997, "Qui phm phn cpv ng tu bin v thp

3.2.12 Trang b in

1 Ngun cp nng lng in cho h thng lm lnh phi c cung cp t t nht 2 t my pht.

2 Cng sut ca cc my pht in c ni trn phi sao cho ngay c khi mt my pht bt k ngng hotng cc my pht cn li vn c kh nng duy tr nhit ca bung lnh ch r du hiu m t b sung

cho k hiu phn cp.

3 Cu to ca thit b in c b tr trong h thng lm lnh phi tun th cc qui nh Chng 1 v 2, Phn4 ca TCVN 6259 : 2003 "Qui phm phn cp v ng tu bin v thp".

3.3 Cc thit b lm lnh trong bung lnh

3.3.1 Gin lnh

Gin lm lnh nc mui hoc gin lm lnh dn n trc tip trong mi bung lnh phi c chia t nht l 2phn c b tr sao cho mi phn c th ngt c khi cn thit.

3.3.2 Thit b lm lnh khng kh

Cc ng xon lm lnh trong mi thit b lm lnh khng kh phi c b tr khng t hn hai phn, mi phn c th ngt c khi cn thit.

3.3.3 Qut tun hon khng kh lm lnh

Khi s tun hon khng kh l thuc duy nht vo mt qut v ng c, s b tr li vo phi sao cho qut vng c c th d dng tho ra c sa cha hoc thay th ngay c khi bung l nh c xp y hnglnh. Khi c lp nhiu qut v ng c v nhit bung lnh c th c duy tr trong mt phm vi chophp ngay c khi mt thit b khng s dng, th yu cu ni trn khng phi p dng.

3.3.4 Thit b iu chnh nhit t ng

Khi trang b thit b iu chnh nhit t ng iu chnh nhit trong bung lnh, phi trang b mtvan hoc h thng iu chnh thao tc bng tay d phng. C th trang b hai h thng iu chnh t ng

18

8/8/2019 TCVN 6275_V_E

13/48

tcvn 6275 : 2003, Chng 3

c b tr sao cho mi h thng c th thao tc d dng bng s chuyn i h thng.3.3.5 S chnh lch nhit

cc tu ch hng lnh khng bao gi, s chnh lch nhit gia bung lnh v cht lm lnh phi ciu chnh sao cho s mt nc ca hng v s ng tuyt cc kh c lm l nh trong mi bung lnh l nh

nht.

3.3.6 M km cc kt v ng dn nc mui

Cc b mt tnh ca cc kt v ng dn nc mui chu tc dng ca nc mui phi khng c m km.Tuy nhin, qui nh ny khng p dng khi cc kt nc mui l kiu ng kn v c trang b mt hocnhiu ng thng hi dn ra khng gian thong mt v tr m s khng xy ra h hng do kh x v ccu h phi c lp mng ngn bng li kim loi khng g, hoc khi cc kt l kiu h v cc ngn m kt c t phi c thng gi c hiu qu.

3.3.7 Chng n mn cc ng dn cht lm lnh trong bung lnh

Mt ngoi cc ng dn cht lm lnh s cp hoc nc mui bng thp trong bung lnh hoc nm trong lpcch nhit ca n phi c bo v thch hp khi s n mn bng m km, sn chng n mn hoc bng ccphng php khc. Khi cc ng c ni bng mi ni ren hoc bng hn, cc ch khng c m hoc snca cc ng phi c ph vt liu chng n mn c hiu qu sau khi th p lc.

3.4 Cc thit b khc trong bung lnh

3.4.1 Thit b kh tuyt

cc bung lnh hot ng di 0oC, phi trang b phng tin kh tuyt mt cch c hiu qu cc ngxon lm lnh khng kh trong bung lnh.

3.4.2 H thng lm sch kh

cc bung dng cha cc hng lnh yu cu thng gi c iu khin phi trang b h thng lm sch kh.Trong trng hp ny, mi bung phi c trang b l thng gi vo v thi ra ring ca chng, v mi lthng phi c trang b mt thit b ng kn kh. V tr ca l thng kh vo phi c la chn gim nmc ti thiu kh nng khng kh nhim bn i vo bung lnh.

3.4.3 Thit b si m hng rau qu

Khi chuyn ch cc loi hng rau qu d hng do nhit thp vo cc khu vc m nhit xung quanhc th thp hn nhit chuyn ch th phi trang b thit b si m bung hng.

3.5 Bung thit b lm lnh

3.5.1 Trng thi ca bung thit b lm lnh

Cc bung thit b lm lnh phi c trang b cc thit b c kh nng thi v thng gi v c cch ly bngcc vch ngn kn kh khi bung lnh k bn.

19

8/8/2019 TCVN 6275_V_E

14/48

tcvn 6275 : 2003, Chng 4

Chng 4 cc qui nh ring i vi thit b lmlnh s dng cht lm lnh amnic

4.1 Qui nh chung

4.1.1 Qui nh chung

Thit b lm lnh s dng cht lm lnh amnic phi l h thng lm lnh gin tip v ch s dng amniclm cht lm lnh s cp.

4.1.2 nh ngha

Nu khng c qui nh no khc, cc thut ng dng trong Chng ny c nh ngha nh (1) n (4)di y :

(1)"Kh" l kh amonic c s dng lm cht lm lnh.(2)"Ty kh" l x sch cc kh khng ngng t khi bu ngng.(3)"Thng cha" l thng cha kh b sung.(4)"H thng thi kh" l h thng dng loi tr kh khi khoang mt cch nhanh chng, gm c: h thng

thng gi, h thng hp th kh, h thng (to) mn nc, kt nc hp th kh v.v...

4.1.3 Bn v v ti liu

Ngoi cc bn v v ti liu qui nh cc mc khc, ni chung phi trnh thm cc bn v v ti liu sauy :

(1)B tr thit b pht hin kh.(2)B tr chung bung my lm lnh.

4.2 Thit k

4.2.1 Qui nh chung

1 Cc bnh chu p lc c s dng trong thit b lm lnh phi tha mn cc yu cu ca Nhm I c nhr Chng 10, Phn 3 ca TCVN 6259 : 2003 "Qui phm phn cp v ng tu bin v thp" v cc ng dncht lm lnh s cp (sau y gi l "ng dn cht lm lnh") phi c phn loi vo Nhm I c qui nh Chng 12, Phn 3 ca TCVN 6259 : 2003 "Qui phm phn cp v ng tu bin v thp".

2 Thit b lm lnh phi c cc bnh cha ph dung tch c th thc hin sa cha v bo dng m khngx kh ra kh quyn. Tuy nhin, cc bnh cha ph c th c min nu cht lm lnh trong bnh cha cdung tch ln nht c th cha vo mt bnh cha khc no .

4.2.2 Vt liu

1 Cc vt liu c th b n mn cao (nh ng, km, cadimi, hoc cc hp kim ca chng) v cc vt liu chathy ngn khng c s dng cc v tr tip xc vi amnic.

2 Thp nicken khng c dng trong cc bnh chu p lc v cc h thng ng ng.

3 Cc van bng gang khng c dng trong h thng ng dn cht lm lnh.

4 Cc vt liu dng cho bu ngng c lm mt bng nc bin phi c la chn lu n s n mn donc bin.

20

8/8/2019 TCVN 6275_V_E

15/48

tcvn 6275 : 2003, Chng 44.3 Thit b lm lnh

4.3.1 My nn cht lnh

My nn cht lm lnh phi c phng tin dng t ng my nn khi p sut pha cao p ca h thng

dn cht lm lnh cao qu mc. Ngoi ra, phi c mt h thng bo ng bng m thanh v nh sng khi ccphng tin hot ng, lp trong bung thit b lm lnh v ni kim tra.

4.3.2 Mi ni ng

Cc mi ni ng cho h thng ng dn cht lm lnh phi c gng c hn theo kiu gip mi.

4.3.3 Thit b gim p

Kh cht lm lnh c x t van gim p phi c hp th bng nc tr khi kh c dn v pha thp p.

4.3.4 Dng c o mc cht lng

Nu dng c o mc cht lng lm bng thy tinh c s dng cc v tr thng xuyn c p sut th chngphi tha mn cc yu cu sau :

(1)Phi dng knh kiu phng trong dng c o mc cht lng, v phi cu to sao cho dng c c bo vthch hp chng cc tc ng bn ngoi.

(2)Cu to ca van ngt dng c o mc cht lng phi sao cho t ng ngt dng cht lng nu knh v.4.3.5 Ty kh

Khng c x kh trc tip ra kh quyn qua cc van ty kh m phi dng nc c hp th kh.

4.3.6 Bu ngng

Phi dng ng dn ring x nc bin lm mt cho bu ngng. ng ny phi c dn thng ra ngoi mntu khng i qua cc khu vc sinh hot.

4.4 Bung thit b lm lnh

4.4.1 Kt cu v b tr

1 Bung t thit b lm lnh v cc bnh cha (sau y gi l "bung thit b lm lnh") phi l bung ringbit c cch li vi cc bung khc bng cc vch ngn v boong kn kh sao cho amnic b r khng i vocc bung khc. Bung thit b lm lnh phi c cc ca ra vo tha mn cc yu cu sau y:

(1)Bung thit b lm lnh phi c t nht 2 ca ra vo cng xa khi mi bung khc cng tt. t nht mt cara vo phi c dn thng n boong thi tit. Tuy nhin, nu khng th b tr ca ra vo n thngboong thi tit th t nht mt li ra vo c ca kiu nt chn khng kh.

(2)Ca ra vo khng dn n boong thi tit phi l ca c kn cao v t ng.(3)Cc ca ra vo phi c kh nng thao tc c d dng v m ra pha ngoi.

2 Bung thit b lm lnh phi khng k vi cc khu vc sinh hot, bung y t hoc bung iu khin.

3 Hnh lang dn n bung thit b lm lnh phi tha mn cc yu cu sau:

(1)Nu hnh lang k vi khu vc sinh hot, bung y t hoc bung iu khin th n phi c cch li bngvch hoc boong kn kh.

(2)Hnh lang ny phi c cch li vi cc hnh lang dn n cc khu vc sinh hot v c dn thng nboong thi tit.

4 Cc ch cp in v ng ng t thit b lm lnh xuyn qua vch v boong kn kh phi c kt cu kn kh.

21

8/8/2019 TCVN 6275_V_E

16/48

tcvn 6275 : 2003, Chng 4

5 Cc mng tiu nc c c thch hp phi c trang b ti v tr thp hn thit b lm lnh v cc bnh chatrong bung thit b lm lnh sao cho amnic lng khng r ra ngoi bung my.

6 Phi c mt h thng tiu nc c lp trong bung thit b lm lnh vic tiu nc trong bung ny khngx vo cc h nc y tu hoc cc ng ht kh h ca cc bung khc.

4.5 H thng thi kh

4.5.1 Qui nh chung

Phi t trong bung thit b lm lnh mt h thng thi kh gm h thng thng gi, h thng hp th kh, hthng mn nc v kt nc hp th kh kh b r c th c loi tr nhanh chng khi bung thit b lmlnh.

4.5.2 H thng thng gi

1 Phi lp trong bung thit b lm lnh mt h thng thng gi c gii tha mn cc yu cu sau y bung

ny c thng gi thng xuyn :(1) H thng thng gi phi c lu lng thch hp m bo thay i khng kh trong bung thit b lm

lnh t nht 30 ln trong mt gi.(2) H thng thng gi ny phi c lp vi cc h thng thng gi khc trn tu v phi c kh nng vn

hnh c t bn ngoi bung thit b lm lnh.(3) Ca x phi c t cch ca np khng kh vo, cc ca bung sinh hot, bung phc v v trm iu

khin gn nht theo phng ngang trn 10 m v cch boong thi tit theo phng thng ng trn 4 m.(4) Ca np khng kh phi c b tr mt v tr thp v ca x phi c b tr mt v tr cao trong

bung thit b lm lnh sao cho kh khng tch t trong bung v trong ng x.(5) Qut ht v ng x m trong lp qut ht phi c cu to sao cho khng pht sinh tia la theo bt k

im (a) n (c) no c nu di y :

(a) Hoc cnh hoc v bao hoc c hai c lm bng vt liu khng dn in, phi kim lo i.(b)Vt liu kim loi khng cha st c s dng lm cnh v v bao.(c) Nu vt liu khng cha st c dng lm cnh v v bao, khe h mp cnh phi ln hn 13 mm.

Tuy nhin, vic s dng kt hp nhm hoc hp kim ma-gi cha st c kh nng pht tia la c khic khe h, v th cc vt liu nh vy khng c dng trong bung thit b lm lnh. Thng thng,cc ng c dn ng qut phi l kiu lp ngoi.

2 Phi lp cc h thng thng gi c lp trong cc hnh lang dn n bung thit b lm lnh. Tuy nhin, nuh thng thng gi c ni -1 trn c trang b ng dn c th dng ht khng kh trong hnh lang thkhng cn phi lp h thng thng gi c lp.

4.5.3 H thng hp th khPhi lp t mt h thng hp th kh tha mn bt k yu cu no cho di y, c kh nng loi tr nhanhchng cc kh r lt t bung thit b lm lnh, v c th vn hnh c t bn ngoi bung ;

(1) Thit b lc:(a) Thit b lc phi c thit k c nng sut thng qua thch hp hn ch nng kh tp trung ti

qut ht i n ging t di 25phn triu.(b) Bm cho thit b lc phi t ng khi ng khi nng kh tp trung trong bung thit b lm l nh

vt qu 300phn triu.(2) H thng ng phun ti nc:(1)Lng nc phun ra phi sao cho c th c hp th kh r lt tha mn yu cu.(2)u phun phi l kiu c ng kim duyt. Thng thng u phun phi c b tr sao cho tm phunca chng bao ph ton b thit b lm lnh trong bung.(3)Khi nng kh tp trung trong bung thit b lm lnh vt qu 300phn triu, bm dng phun ti

22

8/8/2019 TCVN 6275_V_E

17/48

tcvn 6275 : 2003, Chng 4

nc phi t ng khi ng c.

4.5.4 H thng mn nc

Tt c cc ca ra vo bung thit b lm lnh phi c h thng mn nc c th vn hnh c t pha ngoi

bung ny.

4.5.5 Kt nc hp th kh

Kt nc hp th kh tha mn cc yu cu nu di y phi c t v tr thp hn bung thit b lmlnh sao cho amnic lng b r c th thu li c nhanh chng.

(1)Kt phi c dung tch sao cho c th thu li y lng nc m n c th hp th cht lm lnh chay t nht trong mt thit b lm lnh.

(2)Phi t trong kt mt h thng cp nc t ng lun lun duy tr c trng thi in y ca kt(3)Nc hp th trn t kt phi c lm long hoc trung ha v sau c x thng ra ngoi tu, khng

dn cc ng x ny i qua khu vc sinh hot.

(4)Kt phi c cc phng tin thu li lng amnic lng thot ra trong bung thit b lm lnh. Phitrang b mt kha vi thch hp ngn nga dng chy ngc ca kh t kt.

(5)Tt c cc ng thng hi ca kt phi c ni n ng x ca h thng thng gi nu 4.5.2.4.6 H thng pht hin kh v bo ng

4.6.1 Cc yu cu lp t

1 Phi trang b trong bung thit b lm lnh cc h thng pht hin kh v bo ng tha mn cc yu cu sauy:(1) t nht phi c mt thit b pht hin kh tha mn cc yu cu c nu di y lp t pha trn mi

thit b lm lnh:

(a) Thit b pht hin phi pht bo ng khi nng kh tp trung vt qu 25phn triu.(b) Khi nng kh tp tp trung vt qu 300phn triu thit b pht hin phi t ng dng thit b lm

lnh, t ng kch hot vic x kh v t ng pht bo ng.(2) Phi trang b s lng thit b pht hin kh d chy khi s tp trung kh ln n 4,5% th ngun cp

nng lng cho thit b in trong bung thit b lm lnh phi c ct v h thng bo ng hot ng.(3) H thng bo ng phi pht tn hiu bng m thanh v nh sng gn ca ra vo bn trong v bn ngoi

bung thit b lm lnh v ti cc v tr kim tra.(4) Phi trang b mt my pht iu khin bng tay dng cnh bo vic r gn ca ra vo v bn ngoi

bung thit b lm lnh.

2 Phi trang b trong cc hnh lang dn n bung thit b lm lnh cc h thng pht hin kh v bo ng tha

mn cc yu cu sau y :(1)Thit b pht hin kh phi pht ng h thng bo ng khi nng kh tp trung vt qu 25 phn triu.(2)H thng bo ng phi pht tn hiu nghe v nhn thy c trong hnh lang v gn ca ra vo bung

thit b lm lnh.

3 Thit b pht hin kh phi c kh nng hot ng lin tc v c ng kim cho l thch hp.

4.7 Thit b in

4.7.1 Qui nh chung

1 Thit b in trong bung thit b lm lnh yu cu phi hot ng c trong trng hp s c r, h thngpht hin kh v bo ng, v chiu sng s c phi l kiu c chng nhn l an ton dng trong mitrng c th chy c lin quan.

23

8/8/2019 TCVN 6275_V_E

18/48

tcvn 6275 : 2003, Chng 4

2 Thit b in trong bung thit b lm lnh khng phi l loi nu -1 trn, yu cu phi t ng ngt bngcc phng tin ngt mch c t bn ngoi bung thit b lm lnh khi thit b pht hin hi ga, c quinh 4.6.1-1(2), kch hot.

3 Nu h thng u phun nc c t trong bung thit b lm lnh l h thng hp th kh th ton b cc

trang thit b in trong bung thit b lm lnh phi l kiu kn nc.

4.8 Trang b an ton v bo v

4.8.1 Qui nh chung

Thng thng, phi c cc trang b an ton v bo v nu di y, v phi c ct gi nhng v tr bnngoi bung t thit b lm lnh sao cho c th d ly c trong trng hp r lt cht lm lnh. Cc ch ctgi phi c lm du c th d pht hin :(1)Qun o bo v (m bo v, ng an ton, gng tay v.v...) 2(2)Thit b th c lp (c th hot ng t nht 30 pht) 2(3)Knh bo h 2(4)Thit b ra mt (eye washer) 1(5)a xt Borc(6)n pin (s c) 2(7)Dng c o in tr cch in 1.

24

8/8/2019 TCVN 6275_V_E

19/48

tcvn 6275 : 2003, Chng 5

chng 5 bung lnh

5.1 Kt cu bung lnh

5.1.1 Vt liu dng cho bung lnh

Boong, sn v cc vch ngn ca bung lnh phi c lm bng cc vt liu m bo kn kh. Tuy nhin, ccvch phn chia gia cc bung lnh cha loi hng ha m n khng lm h hng hoc tc ng c hi nhng ha trong bt k bung no khc, c th c lm bng cc vt liu thch hp khc ty theo s chpthun ca ng kim.

5.1.2 S kn kh ca thit b ng kn

Cc thit b ng kn nh np hm hng, ca ra vo, cc np y tu v np l ngi chui to thnh mt bphn ca v bc cch nhit ca cc bung lnh ring bit phi c lm kn kh. Khi np hm hng hoc ccnt kn chu tc dng ca mi trng xung quanh, chng phi c trang b m kp.

5.1.3 Hn v vt liu ca cc cu trc thp trong bung lnh

Phi ch c bit i vi vic hn v vt liu ca cc kt cu c hn trc tip vi cc thnh phn kt cuchnh ca thn tu v phi loi b s gin on v kt cu v/hoc khuyt tt trong mi hn.

5.1.4 Cc g ca l ngi chui v.v...

Cch nhit np kt vng cc l ngi chui v cc np y tu phi c g kn cht lng vi mt cao thchhp ngn chn s thm vo lp cch nhit.

5.1.5 S xuyn qua ca ng thng gi v cc ng xuyn qua boong, cc vch ngn ...

1 Cc ng thng gi khng c xuyn qua cc vch chng va di boong mn kh. Cc ng xuyn qua ccvch ngn kn nc khc phi c trang b mt thit b ng kn c hiu qu c th iu khin c mt vtr pha trn boong mn kh c th tip cn c vo mi lc. v tr thao tc phi trang b mt thit b chbo ng ang c m hay ng.

2 Cc ng lm lnh xuyn qua vch ngn hoc boong ca bung lnh phi khng tip xc trc tip vi cu trcthp. S kn kh ca vch ngn hoc boong phi c bo m. Khi cc ng ny xuyn qua tn boong hocvch kn nc, cc chi tit v bt kn ca np bt phi chu c la v kn nc.

3 Cc ng thng gi, khng kh hoc cc ng xuyn qua bung lnh n cc bung khc phi c lm kn kh vng cc b phn xuyn qua cch nhit, v chng phi c cch nhit c hiu qu trong bung lnh.

4 Cc ng khng kh, ng o, ng ht kh v cc ng khc c dn t bn ngoi bung lnh v xuyn quabung lnh phi c cch nhit c hiu qu v phi lu c bit n s b tr cc ng ng ny phngs ng cng cc cht lng trong cc ng ny.

5.1.6 Lp cch nhit ...

Lp cch nhit, u ht nc bn y tu v np ca chng, np hm hng v ca ra vo i vi bung l nhphi c cu to bng cc vt liu chu hi nc hoc c ph bng cc vt liu nh vy.

5.1.7 Vn lt hng

Vn lt hng phi c lp v b tr trn ton b vch ng ca bung l nh cung cp khng gian cho stun hon khng kh v ngn nga hng tip xc vi cch nhit hoc gin lm l nh. Tuy nhin, khi hnh dnglp cch nhit, phng php xp hng v.v... l thch hp, v khng cn vn lt, c th khng yu cu c vnlt.

25

8/8/2019 TCVN 6275_V_E

20/48

tcvn 6275 : 2003, Chng 5

5.1.8 Li lt sn

Phi trang b li lt sn c chiu dy v hnh dng thch hp trn sn bung lnh cung cp khng gianthch hp gia sn v hng tun hon khng kh t do v bo v cch nhit sn khi cc h hng c hc dobc d hng. Tuy nhin, khi lp cch nhit sn tha mn cc qui nh trn hoc hng ha phi khi ch c

treo hoc trn cc b thch hp, khng yu cu c li lt sn.

5.2 Cch nhit v vt liu cch nhit

5.2.1 Vt liu cch nhit

1 Vt liu lm cch nhit phi c ng kim ng hoc chp nhn th mi c s dng.

2 Nu s dng vt liu cch nhit dng tm, n phi c bn thch hp. Khi dng cht gn lin kt cc tmvi nhau, n phi khng c mi v khng hp th bt k mi no t hng ha.

5.2.2 Lp ph bo v bn ngoi

1 Cu trc thp c cch nhit phi c lm sch hon ton v c ph cht chng n mn trc khi ccch nhit.

2 Tt c cc bu lng, ai c thp v cc chi tit dng g kp khc, m chng chng hoc gi cht vt liucch nhit, cc mi lin kt, cc lp bc v.v... phi c m km hoc c bo v chng n mn bng ccbin php thch hp.

5.2.3 Cch nhit

1 Chiu dy lp cch nhit trn tt c cc b mt v kiu chng trong n phi ph hp vi cc iu kin kthut v s duyt. Cch nhit phi c c nh chc chn sao cho khng b lng ra, khi cch nhit ldng tm, cc mi ni phi c ni i tip tht kht v b tr so le vi nhau. Cc k h khng th trnh c

phi c bt kn bng cc vt liu cch nhit thch hp.

2 Cc thnh phn kt cu m chng ko di vo trong bung lnh phi c cch nhit c hiu qu trn khpchiu di trong bung lnh phng nhit thm nhp vo bung v lm qu lnh mi thnh phn ti ch thmnhp.

5.2.4 Tho cch nhit

1 Cch nhit ca cc ch d tip xc vi nc y tu, cc r ht nc y tu v np l ngi chui vo kt yucu phi l kiu nt v c th tho c.

2 Cch nhit khu vc ng ht kh, ng khng kh v cc ng o v cc ng ng khc phi tho ri c n

mc cn thit tip cn kim tra.

5.2.5 Cch nhit tn bao kt du

Khi cc phn trn ca kt v vch ngn ca kt cha du l mt phn ca vch bung l nh, phi b tr khnggian khng kh rng gia tn bao kt v cch nhit, hoc b mt ca tn bao kt phi ph cht khngngm du v kn du c chp thun vi dy thch hp, trc khi lp cch nhit. Khi c b tr khnggian khng kh gia tn bao kt v cch nhit, phi m bo s thot s ch du r n ng mng v ytu. Ngoi ra, cc khng gian khng kh phi c ng ng thng hi dn ra ngoi tri, v phi t ca thotcc mng ngn bng li kim loi chng n mn.

26

8/8/2019 TCVN 6275_V_E

21/48

tcvn 6275 : 2003, Chng 55.3 Thit b o nhit

5.3.1 S lng nhit k v cm bin

1 Mi bung lnh phi c 2 b nhit k. Mi b nhit k ca bung lnh phi c ni t nht 2 cm bin.

2 Tr khi c qui nh khc, t nht phi trang b trong mi bung s lng cm bin sau y, ty theo th tchca bung :

(1) Th tch n 300 m3 : 4(2) Th tch n 600 m3 : 5(3) Th tch trn 600 m3 : 5 cng vi 1 cho mi 400 m3 ln hn

3 Ngoi cc yu cu c nu -2, phi lp mt cm bin cho mi dng khng kh chnh pha ht v pha cpca mi thit b lm lnh khng kh

5.3.2 Nhit k in

1 Ngun in cho mi dng c o trong bung lnh phi c cp bng mt mch nhnh cui, ring bit.2 Cc cm bin c ni vi nhit k trong bung lnh phi c bo v thch hp khi b h hng c hc.

3 S ghi ca cc nhit k trong bung lnh phi chnh xc vi sai s so vi nhit thc trong ph m vi 0,5oCi vi vng nhit di 0oC v 0,3oC i vi vng nhit t 0oC tr ln.

5.4 Thit b x

5.4.1 Qui nh chung

1 Ngoi cc qui nh ca phn ny, thit b x cn phi ph hp vi cc qui nh thch hp 13.5 Phn 3 caTCVN 6259 : 2003 "Qui phm phn cp v ng tu bin v thp".

2 Tt c cc bung lnh v cc b lm lnh khng kh phi c h thng thot nc d lin tc.

3 Cc khoang bn ngoi bung lnh phi khng x nc vo bung lnh.

5.4.2 Van mt chiu v van bt kn cc ng x mn

1 Cc ng thng nc c dn ra t bung lnh v cc khay ca b lm lnh khng kh phi c cc van mtchiu v van kn cht lng. Tuy nhin, cc ng c dn t gia cc bung trn boong v cc khay ca b lmlnh khng kh trn np kt c th ch trang b cc van kn.

2 Khi cc ng x mn t cc bung lnh v cc khay ca b lm lnh khng kh c ni vi mt ng gpchung, th mi ng nhnh phi c mt van kn cht lng, v t cc khoang hm bn di phi c lp thm

van mt chiu.

3 Khi nhit bung c d tnh t 0oC tr xung, cc ng tho nc cng vi cc van mt chiu v van kncht lng c qui nh -1 v -2 phi c cch nhit tt, nu cn thit.

4 Cc van kn cht lng phi c mt su thch hp v c b tr sao cho c th tip cn lm v sinh vnp y li cht lng.

27

8/8/2019 TCVN 6275_V_E

22/48

tcvn 6275 : 2003, Chng 6

chng 6 th nghim

6.1 Th ti xng ch to

6.1.1 Th p lc v th r

1 Cc b phn thit b, cc bnh chu p lc v cc ng ng p lc chu tc dng vi p sut ca cht lm lnhs cp phi c th thy lc n p lc bng 1,5 ln p sut thit k. Sau khi th thy lc chng phi cth r n p lc bng p sut thit k.

2 Cc b phn thit b, cc bnh chu p lc v cc ng ng p lc dng nc mui phi c th thy lc np lc bng 1,5 ln p sut thit k hoc 0,4MPa, th theo p lc no ln hn.

3 Thng thng phi tin hnh th p lc bng nc hoc du v th r bng khng kh hoc cc cht kh trthch hp hoc bt k kh tr no c thm vo mt s lng nh cht lm lnh.

6.1.2 Th c tnh

1 My nn, qut, bm cht lm lnh s cp hoc bm nc mui v cc ng c lai chng phi c th ctnh ca chng.

2 Cc chi tit hn cc bnh chu p lc v ng dn phi c th ph hp vi cc qui nh thch hp Chng11, Phn 4 ca TCVN 6259 : 2003 "Qui phm phn cp v ng tu bin v thp".

3 Thit b in phi c th ph hp vi cc qui nh Chng 2, Phn 4 ca TCVN 6259 : 2003 "Qui phmphn cp v ng tu bin v thp".

6.2 Th trong khi lp t

6.2.1 Th r

1 H thng cht lm lnh s cp phi c th r sau khi hon thnh s lp rp ng ng trn tu, thng lvi kh tr hoc kh tr c thm mt lng nh cht lm lnh, v th n p lc bng 90% p sut thit ktng ng.

2 H thng nc mui phi c th r sau khi hon thnh s lp rp ng ng trn tu vi p sut th bng1,5 ln p sut lm vic ln nht ca h thng nc mui hoc 0,4 MPa, th theo p sut no ln hn.

6.2.2 Hiu chun nhit k

Cc nhit k phi c kim tra chnh xc im ng bng ca nc sau khi chng c lp trn tu, v chnh xc ca cc nhit k phi ph hp vi cc c im k thut qui nh. S ghi kim tra phi c

trnh cho ng kim vin.

6.2.3 Th tun hon kh

Khi cc qut tun hon khng kh c trang b trong cc bung lnh th phi m bo tc khng kh tunhon v trng thi tun hon khng kh l tha mn.

6.2.4 Th chc nng

Cc thit b iu khin t ng, thit b an ton v tn hiu bo ng phi c xc nh rng chng ho t ngtha mn.

6.2.5 Th trong trng thi khai thc

Tt c cc b phn ca thit b lm lnh phi c vn hnh trong trng thi ti n mc c th c, vphi chng t c rng khng c sai st trn h thng, v s chuyn i sang thit b d phng l d dng.

28

8/8/2019 TCVN 6275_V_E

23/48

tcvn 6275 : 2003, Chng 6

Vic th ny c th thc hin giai on lm lnh lc th cn bng nhit c qui nh 6.2.6.

6.2.6 Th cn bng nhit

Th cn bng nhit phi c tin hnh bng cch c qui nh (1) n (4) di y, o s r nhit

trung bnh qua cch nhit ca bung lnh :(1) Bung lnh phi c lm lnh xung tng bc n nhit thp hn nhit kh quyn t nht 20oC.

Ngoi ra, vic lm lnh phi lin tc cho n khi nhit bung c th c duy tr thc s khng i mkhng c bt k s iu chnh cng sut ca thit b hoc thao tc ng m u n cc my nn cng tc.

(2) Sau khi t c s n nh nh ni trn, cc vic o cn thit phi c tin hnh 1 gi 1 ln trongkhong t nht l 6 gi, gi nhit bung cn bn khng i.

(3) Phi xc nhn rng s r nhit do vic th ny khng ln hn gi tr thit k tnh ton da vo snlng lm lnh c s tha d hp l v vic th c thc hin ng. Bn ghi kt qu o phi trnh chong kim vin.

(4) Khi nhit bung lnh lc th cn bng nhit cao hn nhit qui nh, bung phi c lm lnhxung n nhit qui nh v gi trng thi ny trong t nht 2 gi. Trong thi gian ny phi m bo

hot ng ca ton b h thng l m v tha mn.

6.2.7 Th kh tuyt

Phi th hot ng tha mn ca thit b kh tuyt cho b lm lnh khng kh.

29

8/8/2019 TCVN 6275_V_E

24/48

tcvn 6275 : 2003, Chng 7

Chng 7 kim tra xp hng

7.1 Qui nh chung

7.1.1 Qui nh chung

1 Theo yu cu ca Ch tu hoc i din Ch tu, ng kim vin c th tin hnh kim tra xp hng trn hthng lm lnh ng k ti cng xp hng ph hp vi cc qui nh 7.1.2. Khi hon thnh kim tra vi stha mn ca ng kim vin, "Giy chng nhn kim tra xp hng" s c cp cho tu.

2 Kim tra xp hng c th c thc hin ng thi vi cc kim tra khc ca h thng lm l nh, chng hnnh kim tra hng nm.

3 Nu khng c ng kim vin ca ng kim ti cng xp hng, tr trng hp c cp -2,ng kims chp nhn bin bn kim tra ca mt ngi c thm quyn ng tin cy tin hnh ti cng xp hng khi c ng kim xem xt thch hp, vi iu kin tt c cc qui nh kim tra xp hng c thc hin y.

7.1.2 Cc hng mc phi kim traKhi kim tra xp hng, cc hng mc sau y phi c xc nhn hoc kim tra:

(1) H thng lm lnh phi c kim tra trong trng thi lm vic xc nhn rng n hot ng tt, vnhit trong bung lnh ti lc c ghi li.

(2) ng kim vin phi xc nh rng c nng lng in tha mn cho cc cng vic cn thit ca tu vcho cng sut qui nh ln nht ca h thng lm lnh, ngay c khi mt my pht khng s dng.Khi ngun nng lng in cng c s dng lm ngun cung cp nng lng chnh ca tu, phi xcnh rng nhit bung lnh c th duy tr c gi tr qui nh khi s dng cc my pht cn li.

(3) Cc bung lnh phi c kim tra trong trng thi rng xc nh rng:(a) Chng sch v khng c hi c th tc ng c hi n hng ha c ch.

(b) Cc gin ng nc mui hoc cht lm lnh, ng xon ca b lm lnh khng kh v cc mi nikhng b r.

(c) Cc vn lt hng khi c lp cho cc vch thng ng l tt.(d) Li hoc vt lt hng l c th dng c khi cn thit i vi cc sn hoc boong.(e) Khng c h hng th hin cch nhit hoc cc lp lt ca n trong cc hm hng lnh.(f) Tt c cc ming x v ht nc y tu tiu nc cho cc hm hng lnh l trong iu kin lm

vic tt, v cc van kn nc c trang b.

30

8/8/2019 TCVN 6275_V_E

25/48

Vietn a m sta n d a r d s TCVn 6275: 2003

Rul es f o r Ca r g o Ref r ig er a t i n g In st a l l a t i o n s

Ch a pter 1 GENERAL

1.1 General

1.1.1 Scope

1 The Rules for Cargo Refrigerating Installations (hereinafter referred to as "the Rules") apply to the survey and

construction of cargo refrigerating installations and subsidiary installations including controlled atmosphere

systems (hereinafter referred to as "refrigerating installations") of ships classed or to be classed with Vietnam

Register (hereinafter referred to as "VR") intended to be registered under Chapter 2, Part 1A of the Rules for

the Classification and Construction of Sea-going Steel ships, TCVN 6259 : 2003.

2 For the refrigerating machinery within the refrigerating installations specified in -1 above, the requirements in

the Rules apply to the refrigerating machinery using the primary refrigerants listed below. The surveys andconstructions of the refrigerating machinery using primary refrigerants other than those listed below are to be

as deemed appropriate by the Society.

R22: CHClF2

R134a: CH2FCF3

R404A : R125/R143a/R134a(44/ 52/ 4 wt%) CH F2CF3/CH3CF3/CH2FCF3

R407C: R32/R125/R134a (23/ 25/ 52 wt%) CH2F2 /CH F2CF3/CH2FCF3

R410A : R32/R125 (50/ 50 wt%) CH2F2 /CH F2CF3

R507A : R125/R143a(50/ 50 wt%) CH F2CF3 /CH3CF3

R717: NH3

3 For refrigerating installations of ships with restricted area of service or those of small capacity, some of therequirements in the Rules may be modified appropriately provided that VR considered it acceptable.

4 At the request of the ship owner or his representative, the Surveyor may carry out Loading Port Surveys on

registered refrigerating installations at the loading port in accordance with the requirements in Chapter 7 of the

Rules. On completion of the survey to the satisfaction of the Surveyor a Certificate on Loading Port Survey

will be issued by VR.

5 The survey and construction of controlled atmosphere systems specified in above -1 will be considered

appropriate by VR.

6 The relevant requirements in the Rules for the Classification and Construction of Steel Sea-going Ships apply

to the materials, equipment, installation and workmanship of the systems, unless otherwise specified in the

Rules.

1.1.2 Special installations

The surveys and construction of refrigerating installations to which the requirements in this part can not be

directly applied for a special reason are to be deemed appropriate at the discretion of VR.

1.1.3 Equivalency

Refrigerating installations, which do not comply with requirements of the Rules may be accepted, provided

that they are deemed by VR to be equivalent to those specified in the Rules.

1.1.4 Installation characters

7

8/8/2019 TCVN 6275_V_E

26/48

TCv n 6275: 2003, Chapter 1

1 The refrigerating installations to be registered in accordance with the Rules (excluding the installations

specified in the next -2 ) will be distinguished by the character RMC* or RMC.

2 The refrigerating installations equipped with controlled atmosphere systems to be registered in accordance

with the Rules will be distinguished by the character RMC*.CA or RMC.CA.

1.1.5 Installation notations

1 In General, Installation Characters will be followed by the minimum temperature(s) in the refrigerated

chambers to be maintained with sea temperature maximum.

e.g. -25oC/32oC for No. A, B and C Chambers and -15oC/32oC for N o. D and E Chambers.

(note) -25oC or -15oC indicate the minimum chamber temperatures to be maintained and 32oC the maximum

sea temperature.

2 When an installation is provided with any additional equipment to suit for carriage of special cargoes or quick

freezers for the catch in fishing vessels, appropriate notations will be added to the Installation Character upon

application of the Owner.

e.g. Equipped for carr iage of frui t

Equipped with quick freezers

3 When an installation is provided with the fixed N2 generator as a part of controlled atmosphere system, the

Installation Notation wil l be affixed as follows;

Equipped with fixed N2generator

4 When controlled atmosphere systems are installed for the certain holds only, appropriate notations will be

affixed as follows;

e.g. Equipped for N o.F and G Hol ds

5 When VR considers necessary to distinguish and special features or usage limitation of the installation, other

appropriate notations than those described in -1 to -4 will be affixed to the Installation Character.

1.2 Definitions

1 The definitions of terms which appear in the Rules are to be as specified in the following (1) to (6), unless

otherwise specified elsewhere.

(1) "Refrigerating installations" means refrigerating machinery, insulation for refrigerated chambers, other

related appliances in refrigerated chambers, and controlled atmosphere systems to be registered.

(2) "Refrigerating machinery" means a set of refrigerating units which compose refrigerating cycle, consisting

of compressors, condensers, receivers, evaporators, coolers, piping and fittings, driving motors for the

compressors and refrigerant pumps, automatic controllers, and electrical equipment.

(3) "Refrigerating units" mean in general such machinery as compressors, motors, condensers, evaporators,

pumps, etc., necessary to operate refrigerating cycles among the refrigerating machinery.

(4) "Brine" is a general term for the secondary refrigerants which is cooled by the primary refrigerant and

which is a thermal medium to cool the cargo.

(5) "Design pressures" mean the maximum pressure designed by the manufacturer. However, design pressures

are to be not less than the values specified in Table 1.1. The lowest design pressure of any refrigerant

other than those described in 1.1.1-2 is to be determined each case, but it is not to be less than the

saturated vapour pressure of such refrigerant at 50oC for high pressure side, and that at 40oC for low

pressure side.

(6) "Controlled atmosphere systems "means such systems as to control and maintain the oxygen content at a

low level in the cargo holds by introducing Nitrogen gas therein in order to extend the life of cargoes as

subsidiary installations for cargo refrigerating installations.(7) Anniversary Date is the day corresponding to the expiry date of Classification Certificate, excluding

expiry date of the Classification Certificate.

8

8/8/2019 TCVN 6275_V_E

27/48

TCVn 6275: 2003, Chapter 1

Table 1.1 The lowest design pressur e

Refrigerant R12 R22 R502 R717

HP Side(1)

1.15 1.9 2.0 2.0The lowest designpressure (MPa)LP Side (2) 0.9 1.5 1.6 1.5

Notes:

(1) HP side: The pressure part f rom the compressor delivery side to the expansion valve.

(2) LP side: The pressure part from the expansion valve to the compressor suction valve.

Where a multistage compression system is adopted, the pressure part from the lower-stage

delivery side to the higher-stage suction side is included.

9

8/8/2019 TCVN 6275_V_E

28/48

t c v n 6275: 2003, Chapter 2

Ch a pter 2 SURVEYS

2.1 General

2.1.1 Kinds of surveys

1 Kinds of surveys are as follows:(1) Surveys for Registration (hereinafter referred to as "Registration Surveys") Registration surveys include

the following:

(a)Registration Surveys during Construction

(b)Registration Surveys not Built under the Survey

(2) Surveys for registration maintenance (hereinafter referred to as "Registration Maintenance Surveys")

Registration Maintenance Surveys include the following:

(a) Special Surveys

(b) Annual Surveys

(c) Occasional Surveys

2.1.2 Registration Surveys and intervals of Registration Maintenance Surveys

1 Registration Surveys

(1) Registration Surveys during Construction

Refrigerating installations intended to be constructed and registered with VR under the survey by the

Surveyors in accordance with the designs approved by VR are to undergo the Registration Survey during

Construction. The presence of the Surveyor is required at the following stages of the work. However,

except the case of thermal balance test specified in 6.2.6 of the Rules the requirements may be modified

having regard to the actual status of facilities, technical abilities and quality control at the works.

(a) When the tests of materials in accordance with the requirements in Part 7A of the Rules for the

Classification and Construction of Sea-going Steel Ships, TCVN 6259 : 2003, and other tests necessary

for the approval or acceptance described in 3.1.3-4,5.2.1-1 and 5.2.5 of the Rules are carried out.(b) When materials are appropriated for parts, or when such parts are appropriated for the refrigerating

installations concerned.

(c) When finishing an important part is completed, and if necessary, at a proper time during the middle

stage of construction.

(d) When the tests specified in Chapter 6 are carried out.

(2) Registration Surveys not Buil t under the Survey

Refrigerating installations intended to be registered in a way other than that described in (1) above are to

undergo the Registration Survey when an application for the survey is made.

2 Registration Maintenance Surveys

Refrigerating installations which have been registered are to undergo surveys in accordance with the followingintervals to maintain their registrations.

(1) Special Surveys are to be carried out at intervals specified in 1.1.3-1(4), Part 1B of the Rules for the

Classification and Construction of Steel Ships, TCVN 6259 : 2003.

(2) Annual Surveys are to be carried out at intervals specified in 1.1.3-1(1), Part 1B of Rules for the

Classification and Construction of Sea-going Steel Ships, TCVN 6259 : 2003.

(3) An Occasional Survey: at a time falling on any of (a) to (d) mentioned below, independently of special

surveys and annual surveys.

(a) When main parts of the installations have been damaged, repaired or renewed.

(b) When the installations are modified or altered.

(c) When it is considered necessary by VR that an important part of the installation should be repaired at a

time other than date for the Special or Annual Survey.

(d) When a survey is needed for a reason other than the above.

10

8/8/2019 TCVN 6275_V_E

29/48

TCVN 6275: 2003, Chapter 2

2.1.3 Special Surveys and Annual Surveys carr ied out in advance, etc.

1 Surveys carried out in advance

The requirements for Special Surveys and Annual Surveys carried out in advance are to be in accordance with

the provisions specified in 1.1.4, Part 1B of Rules for the Classification and Construction of Sea-going Steel

Ships, TCVN 6259 : 2003.

2 Postponement of Special SurveysThe requirements for postponement of Special Surveys are to be in accordance with the provisions specified in

1.1.5-1(1) or 1.1.5-1(2), Part 1B of Rules for the Classification and Construction of Sea-going Steel Ships,

TCVN 6259 : 2003.

3 Partial Omission of Surveys

At Special Surveys, the Surveyor may omit the thoroughexamination for items examined in accordance withthe requirements for the Special Survey at the previous Annual Survey or Occasional Survey at his discretion.

4 Modification of Surveys

At Special Surveys, the Surveyor may modify the requirements for cargo refrigerating installations specified in

2.3.1-1, taking into account the size, purpose, construction, history, results of the previous survey and the

present conditions of the installations.

5 Continuous Surveys

(1) For machinery and equipment approved to be applicable by the Society, where they are examined in

regular rotation to complete all the requirements of the special survey within 5 years and the intervals of

consecutive surveys of each item do not exceed 5 years, the examination of them in special surveys may

be properly modified at the discretion of the Surveyor.

(2) The survey in such way as specified in (1) above is referred to as a continuous survey.

2.1.4 Preparation for Surveys and Others

1 All such preparations as required for the survey to be carried out as well as those which may be required by

the Surveyor as necessary in accordance with the requirements in the Rules are to be made by the applicant of

the survey. The preparations are to include provisions of an easy and safe access, necessary facilities and

necessary records for the execution of the survey. Inspection, measuring and test equipment, which Surveyors

rely on to make decisions affecting classification are to be individually identified and calibrated to a standard

deemed appropriate by VR. However, the Surveyor may accept simple measuring equipment (e.g. rulers,

measuring tapes, weld gauges, micrometers) without individual identification or confirmation of calibration,

provided they are of standard commercial design, properly maintained and periodically compared with other

similar equipment or test pieces. The Surveyor may also accept equipment fitted on board a ship and used in

examination of shipboard equipment (e.g. pressure, temperature or rpm gauges and meters) based either on

calibration records or comparison of readings with multiple instruments.

2 The applicant for survey is to arrange a supervisor who is well conversant with the survey items intended forthe preparation of the survey to provide the necessary assistance to the Surveyor according to his requests

during the survey.

3 Surveys may be suspended where necessary preparations have not been made, any appropriate attendant

mentioned in the previous -2 is not present, or the Surveyor considers that the safety for execution of the

survey is not ensured.

4 Where repairs are deemed necessary as a result of the survey, the Surveyor will notify his recommendations to

the applicant of the survey. Upon this notification, the repair is to be made to the satisfaction of the Surveyor.

2.2 Registration surveys

2.2.1 Registration surveys dur ing constr uction

11

8/8/2019 TCVN 6275_V_E

30/48

t c v n 6275: 2003, Chapter 2

1 In a Registration Survey during construction, the construction, materials, scantlings and workmanship of the

refrigerating installation are to be examined in detail in order to ascertain that they meet the full requirements

of each Chapter concerned of the Rules.

2 The refrigerating machinery used in the refrigerating installation intended to be registered with VR may be

acceptable without their related tests by confirming the certificate issued by VR.

3 For the refrigerating installation intended to undergo a registration survey during construction, the followingplans and information in triplicate are to be submitted to VR before the work is commenced.

(1) Specif ications of the refrigerating installation (including particulars of refrigerating machinery units).

(2) Thermal calculation sheets.

(3) General arrangements of the refrigerating machinery (including detailed ventilating arrangements).

(4) Sectional assembly of refrigerant compressors and detailed plans (material to be indicated) of

reciprocating compressor crankshafts, or rotors of screw type compressors, or rotors, discs and casings of

turbo compressor, and plans of speed-increasing gear.

(5) Detailed plans of pressure vessels subject to the primary refrigerant pressure (condensers, receivers,

evaporators (brine coolers), oil separators, surge tanks, inter coolers, etc.).

(6) Piping arrangements of primary and secondary refrigerants and cooling water (materials, diameter and

thickness of pipes are to be indicated).(7) Arrangements of refrigerated chambers (including ductings for air circulation and venti lation).

(8) Wiring diagram for the refrigerating installation and arrangements of electric appliances.

(9) Wiring diagram in refrigerated chambers (including details of construction of penetration of the

insulation).

(10) Kind of insulation on all surfaces, physical properties, thickness and methods of attachment of the

insulation and linings (including detailed construction and insulating methods of hatch covers, access

doors, ventilating ducts, scupper and bilge).

(11) Drainage arrangements and defrosting arrangements in refrigerated chambers and spaces in which the air

coolers are installed.

(12) Arrangements of thermometers or sensors in refrigerated chambers and air coolers, and the name of

manufacturer and the type of the sensors are to be informed.

(13) Explanatory documents to show the function of automatic temperature controls.

(14) Heat balance tests and measuring plans (performance diagrams of compressors, fans, and their driving

motors are to be submitted as well).

(15) Other documents considered necessary by VR.

4 Notwithstanding the requirements in -3, submission of some of the plans and documents specified in -3 may

be omitted, in case where the refrigerating installation are intended to be constructed at the same

manufacturer's work based on the plans and documents which have been approved by VR.

2.2.2 Registration Surveys not built under the VR' s survey

1 General

In an Registration Survey not built under the survey, the refrigerating installation is to be examined on their

construction, materials, workmanship and actual conditions as required for the special survey corresponding to

their age, in order to ascertain their effectiveness.

2 Tests

In the Registration Survey not built under the survey, operation tests and other various tests are to be carried

out in accordance with the requirements in Chapter 6. However, the heat balance test may be replaced with

other test or omitted where the Surveyor approves it.

3 When a refrigerating installation is intended to undergo the Registration Survey not built under the survey,

plans and documents are to be submitted as may be required by the requirements in 2.2.1.

2.3 Registration maintenance surveys

12

8/8/2019 TCVN 6275_V_E

31/48

TCVN 6275: 2003, Chapter 2

2.3.1 Special surveys

1 At a special survey, the examinations required by the following (1) to (18) are to be carried out.

(1) An examination of the refrigerating installation log book is to be made to trace the operating condition of

the installation during navigation.

(2) Insulation linings and their fastening are to be examined. Any indication of dampness or deterioration of

the insulation is to be investigated.(3) Air circulation ducts, hatch covers and their seal, access doors and their fastening, venti lating system and

their closing means are to be examined. Care is to be given to the condition of penetrating parts where

ducting or ventilating pipes pass through the deck plating.

(4) Bilge ways, wells, strainers, suction and sounding pipes, scupper pipes together wi th non-return valves

and water sealed traps fitted to them are to be cleaned and examined. Air cooler defrosting arrangements

and their drainage arrangements are also to be examined.

(5) Condition of air coolers' cooling coils, cooling grids (including brine) in refrigerated chambers is to be

examined.

(6) Shells of condensers, receivers, evaporators, separators, driers, filters and other pressure vessels exposed

to the primary refrigerant pressure, and their connections and piping are, as far as possible, to be

examined externally.(7) Insulation on the surfaces of pressure vessels, pipe connections and piping is to be examined for

dampness or deterioration.

(8) Reciprocating compressors with their lubricating system are to be opened up and examined. In the case

of screwed-type compressors or compressors deemed appropriate by VR, the interval of opening up may

be modified by VR, provided their working condition is found satisfactory.

(9) Condenser cooling water pumps, primary refrigerant pumps and brine pumps are to be opened up and

examined.

(10) Insulated pipes carrying the refrigerant are to be examined both outside and inside the insulated

chambers, removing the insulation to the extent necessary for checking their condition, especially of the

locations in which pipes are connected by butt welding in place or screwed couplings.

(11) All pressure relief valves throughout the refrigerating plant are to be adjusted on their relieving pressures.(12) All automatic controls, safety devices and alarms are to be tested for their satisfactory function.

(13) Randomly selected thermometers and apparatus used for measuring the temperature in the chambers and

of air in suction and delivery main stream are to be checked for their accuracy.

The Surveyor may at his discretion accept the checking records made by some reliable persons.

(14) The insulation in refrigerated chambers is to be carefully examined, and bored where considered

necessary in order to determine the integrity and dryness. These test holes are subsequently filled

carefully.

(15) Brine pipe system is to be tested to a pressure of 1.5timesthe design pressure or 0.4MPawhichever is the

greater.

(16) Pressure vessels are to be opened up for examination, and afterward pressure tested in accordance with

the following procedures:(a) The coils of gas condensers of the coil-in-casing type are to be examined and tested to a pressure of

1.5timesthe high pressure side design pressure. Where it is impracticable to remove the coils they

may be examined through inspection holes and tested in place.

(b) The coils of evaporators of the coil-in-casing type are to be examined and tested to a pressure of

1.5timesthe low pressure side design pressure. Where it is impracticable to remove the coils, they

may be examined through inspection holes and tested in place.

(c) Gas condensers of the shell-and-tube type and gas evaporators (brine coolers) of the shell-and-tube

type in which the primary refrigerant is in the shell, are to have the water or brine end covers

removed and the tube plates, tube ends and inside the end covers examined. Afterwards, the shells

are to be tested to a pressure equal to the high pressure side design pressure.

(d) Gas evaporators (brine coolers) of the shell-and-tube type in which the brine is in the shell are tohave the primary refrigerant end covers removed and the tube ends and inside the end covers

examined. The shells are to be tested to a pressure of 1.5times the design pressure or 0.4MPa

13

8/8/2019 TCVN 6275_V_E

32/48

t c v n 6275: 2003, Chapter 2

whichever is the greater. After refitting the end covers, the primary refrigerant side is to be tested to

a pressure equal to the low pressure side design pressure.

(e) Primary refrigerant receivers are to be tested to a pressure equal to the high pressure side design

pressure. However, when the receivers are designed to use such primary refrigerant as R22, R134a,

R404A, R407C , R410A or R507A, or when they are proved to have no harmful defects such as

erosions or cracks on the inner surface of the vessels by means of ultrasonic test or other effective

non-destructive examinations, the above mentioned pressure test may be omitted.(f ) For pressure vessel for the refrigerant of R22, R134a, R404A, R407C, R410A or R507A, pressure

tests specified in (a) through (e) above may be omitted at the first Special Survey provided the

vessels are found to be in good order.

(17) Current condition of the electrical equipment and electric cables are to be examined. It is to be

ascertained that their insulation resistance is not less than 100,000 between all insulated circuits and

earth. When correct records are maintained, the above examination may be omitted at the discretion of

the Surveyors.

(18) Operation tests of the refrigerating installation are to be carried out.

2.3.2 Annual Surveys

1 At an annual survey, an external examination is to be carried out on the following items (1) to (5). Examination

may also be made on the items which are prepared to be examined in detail or which are opened up by the

Owners' option. If any defects are observed at such examinations, the Surveyor may require open-up

examinations of the suspected items.

(1) Items required in (1) through (7), and (13) in 2.3.1 are to be examined.

(2) Compressors, condenser cooling water pumps, primary refrigerant pumps, brine pumps, air circulation

fans and their driving motors are to be examined externally.

(3) Water end covers of condenser(s) selected by the Surveyor are to be examined externally for corrosion

through inspection holes or other suitable openings.

(4) Tests for insulation resistance are to be made on the motors and controls of compressors, pumps, fans, etc.

and their wiring, and the resistance is to be not less than 100,000 between insulated circuits and earth.However, when correct records are maintained, the above tests may be omitted at the discretion of the

Surveyor.

(5) Random tests are to be made to ascertain that the automatic controls, safety devices and alarms are in

good working condition.

2.3.3 Occasional Surveys

At an occasional survey, examinations or tests on items required are to be carried out in accordance with the

requirements in 2.1.2-3, to the satisfaction of the Surveyor.

14

8/8/2019 TCVN 6275_V_E

33/48

TCVN 6275: 2003, Chapter 3

Ch a pter 3 REFRIGERATING MACHINERY

3.1 General

3.1.1 General requirements

1 Refrigerating machinery are to be designed taking into account their purpose and service conditions.

2 All components of the refrigerating machinery are to be so constructed and arranged that they can be easily

maintained and readily opened up for repair or renewal.

3 Where R717 is used as refrigerant, the refrigerating machinery are to comply with the requirements in this

Chapter and, in addition, they are to comply with the requirements in Chapter 4.

4 Primary refrigerant pipes for R22, R134a, R404A, R407C or R507A are to be classified into Group I I I

specified in 12.1.3, Part 3 of the Rules for the Classification and Construction of Sea-going Steel Ships, TCVN

6259 : 2003. Classification of pipes used for other refrigerants will be considered by VR depending upon the

nature of the refrigerant and their service condition.

5 Pressure vessels for the refrigerant of R22, R134a, R404A, R407C, R410A or R507A are to be classified inaccordance with the requirements in 10.1.3, Part 3 of the Rules for the Classification and Construction of Steel

Sea-going Ships, TCVN 6259 : 2003, according to the design pressure specified in 1.2(5) of the Rules.

6 Refrigerating machinery are to be provided with the following equipment.

(1) Standard thermometer: 2 sets

(2) Hydrometer: 1 set (in the case of brine-cooling)

(3) Refrigerant leakage detector: 1 set

3.1.2 Capacity and number of refr igerating machinery

1 At least two refrigerating units (in general consisting of one refrigerating compressor and its driving motor, one

condenser, one evaporator, one pump and other accessories necessary to operate the unit independently) are tobe provided and so arranged as to be readily interchanged with each other.

2 The refrigerating capacity of the installation is to be sufficient to maintain the temperatures of the refrigerated

chambers specified in the descriptive note added the classification character with of any one unit suspended.

3.1.3 Mater ials and welding

1 Materials used for the refrigerating machinery are to be suitable for the refrigerant used, the design pressure,

the minimum working temperature, etc.

2 Materials used for the primary refrigerant pipes, valves and their fittings are to comply with the requirements

in 12.1.4 to 12.1.6, Part 3 of the Rules for the Classification and Construction of Steel Sea-going Ships, TCVN

6259 : 2003, according to the classes of pipes specified in 3.1.1-4 and4.2.1-1.

3 Materials used for the pressure vessels exposed to the refrigerant pressure (condensers, receivers and other

pressure vessels) are to comply with the requirements in 10.2, Part 3 of the Rules for the Classification and

Construction of Steel Sea-going Ships, TCVN 6259 : 2003, according to the classes of pressure vessels

specified in 3.1.1-5 and4.2.1-1.

4 Materials listed below are not to be used:

(1) For parts exposed to fluorine-substi tuted hydrocarbons:

aluminium alloys containing more than 2% of magnesium

(2) For parts always exposed to water:

aluminium of which purity is less than 99.7% (except corrosion protection treated materials).

15

8/8/2019 TCVN 6275_V_E

34/48

TCVN 6275: 2003, Chapter 3

5 The use of cast-iron valves is to be in accordance with the requirements in Table 3.1. Even when the use of

cast-iron valves are allowed in that Table, such valves are not to be used where the design temperature is lower

than 0oC or higher than 220oC. In this case, such valves may be used at temperatures down to -50oC, even if

the design temperature is lower than 0oC, provided that they are used under a pressure up to 1/2.5timesof the

design pressure.

6 Refrigerating machinery using specific materials such as rubber hoses, plastic tubes, vinyl pipes, etc., or

aluminium alloys is to be approved or accepted by VR, considering the refrigerant used or service conditions.

7 The welding for refrigerating machinery are to comply with the relevant requirements in Chapter 11, Part 3 of

the Rules for the Classification and Construction of Sea-going Steel Ships, TCVN 6259 : 2003.

Table 3.1 Service limitations of valves made of iron castings

Kind of

valvesMaterials Applications

Gray iron castings with specified

tensile strength not exceeding200N/mm2or equivalent thereto

Not to be used

Stop valvesGray iron castings other than

those specified in above,

Spheroidal graphite iron

castings, Malleable iron castings

or equivalent thereto

(1) May be used for design pressure not exceeding 1.6MPa

(2) May be used for design pressure exceeding 1.6MPabut

not exceeding 2.6MPa, provided nominal bore does not

exceed 100mm and design temperature is 150oC or

below.

Relief

valvesAny iron castings Not to be used

Gray iron castings with specified

tensile strength not exceeding

200N/mm2or equivalent thereto

Not to be used

Gray iron castings other than

those specified in above or

equivalent thereto(1) May be used for design pressure not exceeding 1.6MPa

(2) May be used for design pressure exceeding 1.6MPabut

not exceeding 2.6MPa, provided nominal diameter does

not exceed 100mmand design temperature is 150oC or

below.

Automatic

control

valves

Spheroidal graphite iron

castings, Malleable iron castings

or equivalent thereto

Not to be used for design pressure exceeding 3.2MPa.

3.2 Construction etc. of refr igerating machinery

3.2.1 Refr igerant compressors

1 Compressor components subject to the refrigerant pressure (including crankcases in the case of reciprocating

compressors) are to be so designed to withstand the design pressure for HP side. However, when a relief valve

is fitted to the crankcase integral with compressor cylinder, the components mentioned above may be designed

for the design pressure for the relief valve.

2 Where the compressor is lubricated by pressure oil, the compressor is to be stopped automatically when the oil

pressure falls below a preset value.

3 The compressor is to be provided with an alarm or automatic cut off device which operates where condenser

cooling water pressure falls below a predetermined value.

3.2.2 Dr iving machines and gearing

16

8/8/2019 TCVN 6275_V_E

35/48

TCVN 6275: 2003, Chapter 3

Prime movers and step-up gearing for compressors are to be in accordance with the relevant requirements in

Part 3 and Part 4 of the Rules for the Classification and Construction of Sea-going Steel Ships, TCVN 6259 :

2003.

3.2.3 Pressure vessels exposed to the pr imary refr igerant

Design, construction and strength of pressure vessels exposed to the refrigerant pressure (condensers,

receivers, and other pressure vessels) are to be constructed and tested in accordance with the requirements in

10.3 to 10.8, Part 3 of the Rules for the Classification and Construction of Sea-going Steel Ships, TCVN 6259 :

2003 (excluding those in 10.8.3).

3.2.4 Oil separators

Suitable oil separators with drainage are to be provided to the discharge side of the compressor, except when a

unit integrated with evaporator is provided to ensure oil recovery.

3.2.5 Filters

Suitable filters are to be provided in the refrigerant gas lines to the compressors and in the liquid lines to the

automatic regulators. Filters may be omitted provided oil separators fitted have filtrating capability.

3.2.6 Refr igerating dr iers

Driers are to be provided to the refrigerant pipes for R22, R134a, R404A, R407Cor R507A . Driers are to be so

arranged that they can be by-passed or changed over to a stand-by unit without interrupting the operation of

the plant in case of failure. However, such arrangement is not required when change-over to the stand-by unit

is ensured by a unit integrated with the evaporator.

3.2.7 Refr igerant pumps

Where the primary and/or secondary refrigerants are circulated round the system by pumps, a stand-bypump(s) so arranged as to be easily interchangeable with pumps for normal operation is to be provided. Its

capacity is not to be less than that of the largest pump for normal operation.

3.2.8 Condenser cooling water pumps

1 At least two separate condenser cooling water pumps are to be provided and so arranged as to be

interchangeable with each other. In this case, one of the pumps may be used for other purposes, provided that

it is of adequate capacity and its use on other services does not interfere with the supply of cooling water to the

condenser.

2 Condenser cooling water is to be taken from at least two sea connections (suctions). One of the sea

connections is to be provided on the port side and the other on the starboard side.

3.2.9 Piping systems

1 Design, construction, strength, fabrication and outfitting of piping systems are to be in accordance with the

requirements in 12.2 to 12.4 and 13.2 (except 13.2.1-6), Part 3 of the Rules for the Classification and

Construction of Sea-going Steel Ships, TCVN 6259 : 2003.

2 Pipes and pipe flange couplings are to be in accordance with the requirements for air in Table 3/12.8, Chapter

12, Part 3 of the Rules for