38 CNG BO/S 585 + 586/Ngy 26-9-2013

B GIAO THNG VN TI B GIAO THNG VN TI

S: 24/2013/TT-BGTVT

CNG HA X HI CH NGHA VIT NAM c lp - T do - Hnh phc

H Ni, ngy 27 thng 8 nm 2013

THNG T

Ban hnh Quy chun k thut quc gia v ch to, kim tra chng nhn thit b p lc trong giao thng vn ti

Cn c Lut Tiu chun v Quy chun k thut ngy 29 thng 6 nm 2006; Cn c Ngh nh s 127/2007/N-CP ngy 01 thng 8 nm 2007 ca Chnh ph

quy nh chi tit thi hnh mt s iu ca Lut Tiu chun v Quy chun k thut; Cn c Ngh nh s 107/2012/N-CP ngy 20 thng 12 nm 2012 ca Chnh

ph quy nh chc nng, nhim v, quyn hn v c cu t chc ca B Giao thng vn ti;

Theo ngh ca Cc trng Cc ng kim Vit Nam v V trng V Khoa hc - Cng ngh;

B trng B Giao thng vn ti ban hnh Thng t ban hnh Quy chun k thut quc gia v ch to, kim tra chng nhn thit b p lc trong giao thng vn ti.

iu 1. Ban hnh km theo Thng t ny Quy chun k thut quc gia v ch to, kim tra chng nhn thit b p lc trong giao thng vn ti.

M s ng k: QCVN 67:2013/BGTVT. iu 2. Thng t ny c hiu lc thi hnh k t ngy 01 thng 12 nm 2013. iu 3. Chnh Vn phng, Chnh Thanh tra, V trng cc V, Cc trng

Cc ng kim Vit Nam, Th trng cc c quan, n v thuc B Giao thng vn ti, cc t chc v c nhn c lin quan chu trch nhim thi hnh Thng t ny./.

B TRNG

inh La Thng

CNG BO/S 585 + 586/Ngy 26-9-2013 39

QUY CHUN K THUT QUC GIA QCVN 67:2013/BGTVT

QUY CHUN K THUT QUC GIA V CH TO, KIM TRA CHNG NHN THIT B P LC

TRONG GIAO THNG VN TI

National Technical Regulation on Construction, Survey and Certification of Pressure Equipments

of Transport

Li ni u Quy chun k thut quc gia v ch to, kim tra chng nhn thit b p lc

trong giao thng vn ti QCVN 67:2013/BGTVT do Cc ng kim Vit Nam ch tr bin son, B Khoa hc v Cng ngh thm nh, B trng B Giao thng vn ti ban hnh theo Thng t s 24/2013/TT-BGTVT ngy 27 thng 8 nm 2013.

40 CNG BO/S 585 + 586/Ngy 26-9-2013

Mc lc

I. QUY NH CHUNG 1. Phm vi iu chnh 2. i tng p dng 3. Gii thch t ng II. QUY NH K THUT Chng 1. QUY NH CHUNG 1. Quy nh v thit k p lc 2. Quy nh v ch to thit b p lc 3. Quy nh v vt liu ch to thit b p lc 4. Quy nh chung v hn v kim tra khng ph hy (NDT) Chng 2. CC THIT B P LC V B PHN CHI TIT 1. Thn hnh tr v thn hnh cu chu p lc trong v ti trng kt hp 2. y cn v on cn chu p sut trong 3. y cn v on cn chu p sut ngoi 4. y cong chu p sut trong 5. Cc y cong chu p sut ngoi 6. Cc kt cu chung 7. Cc kt cu bn trong 8. Phng php gn kt chung 9. Ca kim tra Chng 3. CC LOI BNH HAI V 1. Yu cu chung 2. Cc loi bnh hai v 3. Thit k cc thn v v y v.

CNG BO/S 585 + 586/Ngy 26-9-2013 41

QUY CHUN K THUT QUC GIA V CH TO, KIM TRA CHNG NHN THIT B P LC

TRONG GIAO THNG VN TI National Technical Regulation on

Construction, Survey and Certification of Pressure Equipments of Transport

I. QUY NH CHUNG 1. Phm vi iu chnh Quy chun ny quy nh v cc yu cu an ton k thut lin quan n thit k,

ch to, sa cha, hon ci, nhp khu, khai thc s dng, cc yu cu v qun l, kim tra, chng nhn an ton k thut v mi trng i vi cc thit b p lc (sau y gi l thit b) trong giao thng vn ti.

Quy chun ny khng p dng i vi chai LPG, cc ni un nc nng dng cho mc ch sinh hot.

2. i tng p dng Quy chun ny p dng i vi cc c quan, t chc, c nhn c lin quan n

qun l, kim tra, nhp khu, thit k, sn xut, hon ci, th nghim v khai thc s dng cc thit b p lc s dng trong giao thng vn ti, cng trnh bin trn phm vi c nc.

3. Gii thch t ng Trong Quy chun ny, cc t ng di y c hiu nh sau: 3.1. Thit b p lc (sau y k hiu l TBAL) l cc bnh, bn, b, xi tc t,

chai, thng dng cha, chuyn ch kh ha lng, cc cht lng hay cht rn dng bt chu p lc hoc khng c p sut nhng khi tho ra dng kh c p sut cao hn 0,7 bar; h thng kh nn hoc kh ha lng; h thng lnh, h thng iu ch v np kh. N bao gm c cc b phn, cc van, p k, v cc thit b khc ghp ni vi nhau t im u tin ni vi h thng ng.

3.2. p sut lm vic cho php l p sut ln nht m thit b c php lm vic lu di.

3.3. p sut thit k l p sut do ngi thit k quy nh lm c s tnh sc bn cc b phn ca thit b chu p lc. p sut ny cha k n p sut thy tnh ti im tnh ton.

3.4. p sut lm vic ln nht l p sut cao nht m b phn c xem xt ca thit b chu p lc phi chu trong iu kin vn hnh bnh thng. p sut ny c xc nh bi cc yu cu k thut ca cng ngh s dng.

42 CNG BO/S 585 + 586/Ngy 26-9-2013

3.5. ng sut thit k l ng sut cho php ln nht s dng trong cc cng thc tnh ton chiu dy ti thiu hoc kch thc ca cc b phn chu p lc.

3.6. Nhit lm vic nh nht l nhit nh nht ca kim loi m b phn c xem xt ca thit b p lc phi chu trong iu kin lm vic bnh thng. Nhit ny c xc nh bi cc yu cu k thut ca cng ngh s dng hay nhit thp nht c ch nh bi ngi t hng.

3.7. Nhit thit k l nhit kim loi ti p sut tnh ton tng ng c s dng la chn ng sut thit k cho b phn ca thit b p lc c xem xt.

3.8. Nhit thit k nh nht ca vt liu l nhit nh nht c trng ca vt liu. Nhit ny c s dng trong thit k la chn vt liu c dai va p trnh nt gy, v l nhit ti vt liu c th c s dng vi bn thit k y .

3.9. Nhit lm vic ln nht l nhit ln nht ca kim loi m b phn c xem xt ca thit b p lc phi chu trong iu kin lm vic bnh thng. Nhit ny c xc nh bi cc yu cu k thut ca cng ngh s dng.

3.10. Chiu dy thc l chiu dy thc ca vt liu s dng trong mt b phn ca thit b p lc c th c ly theo chiu dy nh mc, tr i dung sai ch to c p dng.

3.11. Chiu dy tnh ton nh nht l chiu dy nh nht c xc nh t tnh ton theo cc cng thc chu ti trc khi thm vo phn b sung do n mn hoc cc h s b sung khc.

3.12. Chiu dy cn thit nh nht l chiu dy bng chiu dy tnh ton nh nht cng vi phn b sung thm do n mn.

3.13. Chiu dy danh ngha l chiu dy danh ngha ca vt liu c chn trong cc cp chiu dy thng mi c sn (c p dng cc dung sai ch to c quy nh).

3.14. ng kim l Cc ng kim Vit Nam - Vietnam Register (VR). 3.15. C s ch to (sn xut) l t chc, c nhn sn xut, lp rp, sa cha,

hon ci cc thit b c Cc ng kim Vit Nam nh gi, chng nhn. 3.16. C s thit k l t chc, c nhn hnh ngh kinh doanh dch v thit k

thit b theo cc quy nh hin hnh. 3.17. C s th nghim l cc trm th, phng th nghim ca t chc, c

nhn hot ng trong lnh vc kim tra, bo dng, th nghim vt liu, hn, thit b c chng nhn hoc chp nhn theo Lut Cht lng sn phm hng ha.

3.18. Ch thit b l cc t chc, c nhn qun l, khai thc s dng thit b p lc.

CNG BO/S 585 + 586/Ngy 26-9-2013 43

3.19. Cc bn c lin quan l ngi t hng, ngi thit k, ngi ch to, c quan kim tra v thm nh thit k, nh cung cp, ngi lp t v ch u t.

3.20. Sn phm cng kiu l cc thit b cng nhn hiu, thit k v c cng thng s k thut c sn xut trn cng mt dy chuyn cng ngh.

II. QUY NH K THUT

Chng 1 QUY NH CHUNG

1. Quy nh v thit k thit b chu p lc 1.1. Quy nh chung 1.1.1. Thit k cc thit b p lc phi tun theo cc yu cu ca Phn II v

c ng kim thm nh, cp giy chng nhn. 1.1.2. Ngi thit k phi chu trch nhim v thit k ca thit b p lc p

ng cc yu cu v thit k ca quy chun ny. 1.1.3. bn thit k c la chn m bo rng cc b phn chnh ca

cc thit b chu p lc khng b rn nt do mi. Tuy nhin khi c nhng iu kin mi cc k khc nghit, cn phi c thm d phng trnh xy ra rn nt do mi gy ra.

1.2. Cc iu kin thit k 1.2.1. p sut thit k v tnh ton 1.2.1.1. p sut thit k ca thit b p lc p sut thit k phi l p sut c ch nh bi ngi t hng, bi cc

thng s p dng, hoc c xc nh theo quy chun ny. p sut thit k phi khng nh hn p sut thp nht thit b x p lm vic. Khi s dng a n, th p sut thit k ca thit b p lc phi cao hn p sut

lm vic thng thng c mt khong cch ln gia p sut lm vic v p sut n, nhm trnh s h hng sm ca a n.

1.2.1.2. p sut tnh ton ca mt b phn ca thit b p lc B phn ca thit b p lc phi c thit k cho iu kin khc nghit nht

v p sut v nhit lm vic, khng bao gm p sut th thy lc hay trong qu trnh vn hnh thit b x p.

Thit k thit b p lc cng cn phi thch hp vi mi cht th v t th t thit b p lc trong qu trnh th thy lc.

44 CNG BO/S 585 + 586/Ngy 26-9-2013

xc nh p sut tnh ton ca mt b phn, phi tnh thm p sut do ct p thy tnh ca cht lng cha trong thit b p lc hay chnh p do dng chy ca cht lng.

p sut tnh ton ca bt k phn no s dng chiu dy thc t tr i n mn cho php v iu chnh thm chnh v ct p thy tnh, hay chnh p, hay nhit , hay bt k s kt hp no ca cc nguyn nhn trn c th xy ra di iu kin t c li nht phi ti thiu bng p sut thit k ca thit b p lc.

1.2.1.3. p sut bn ngoi Vi cc thit b p lc hoc b phn ca thit b p lc b nh hng bi iu

kin chn khng hoc p sut ngoi hoc s chnh lch p sut ca hai pha i din ca phn c xem xt, p sut tnh ton cn phi l p sut chnh lch ln nht m phn thit b p lc phi chu ti iu kin khc nghit nht v nhit v chnh p c xt n tn tht c th v p sut bt c pha no ca phn thit b p lc c nh gi. Trong cc trng hp lin quan, p sut tnh ton cn phi tnh ton trng lng bn thn ca phn thit b p lc da trn chiu dy thc ca tm bao gm c d phng n mn.

Vi cc thit b p lc ch chu chn khng bn trong, p sut thit k bn ngoi l gi tr nh hn trong hai gi tr: 101kPa hoc gi tr cao hn p sut bn ngoi cao nht c th 25%. Khi p sut thit k nh hn 101kPa, thit b p lc phi c cung cp cng vi thit b x chn khng theo mt kiu thch hp ng tin cy.

Khi mt trong cc iu kin sau s dng cho thit b p lc chn khng, p sut tnh ton c th gim n hai phn ba p sut thit k bn ngoi (bng cch gim h s an ton danh ngha cho thn, y v cc vng gia cng t 3 cn 2):

a) S un dc ca thit b p lc khng gy nh hng n s an ton; b) Thit b p lc to thnh dng v chn khng cho mt thit b p lc khc

v un dc ca v ngoi khng dn n s h hng ca thit b p lc bn trong hay c cu ;

c) Thit b p lc khng c ng i hay sn thao tc cao hn ct nn 2m; d) Thit b p lc l kiu mt v v khng cha cht gy hi v khng cao qu 5m; e) Cc im v tai mc cp c thit k v b tr trnh un dc; f) Kim tra trn v hnh dng ca thit b p lc. Phi tnh d phng i vi cc iu kin chn khng c th pht sinh trong

mt s trng hp thng thng vi p sut trong, v d cc bnh cha hi nc v cc loi hi ngng nhit mi trng thp.

CNG BO/S 585 + 586/Ngy 26-9-2013 45

1.2.2. Nhit thit k v nhit lm vic 1.2.2.1. Nhit thit k cho cc thit b p lc (tr thit b p lc lm bng

kim loi nhiu lp) Nhit thit k vi cc thit b p lc kn (tr cc thit b p lc lm bng

kim loi nhiu lp) phi c ly nh nhit kim loi, v cng vi p sut tnh ton, nhit a n chiu dy ln nht ca b phn c xem xt. Nhit khng c ly nh hn nhit kim loi t n ti chiu dy trung bnh thit b p lc ca thnh khi b phn ny p sut tnh ton.

Nhit kim loi ti thnh ca thit b p lc c ly bng nhit ca mi cht cha bn trong, tr trng hp khi tnh ton, th nghim cho php s dng nhit khc.

i vi thit k chng gy gin, nhit lm vic nh nht phi c s dng lm c s.

Phi tnh d phng thch hp cho cc tn tht c th ca phn chu la hoc bo n.

Bng 1. Nhit thit k cho phn b gia nhit

Loi gia nhit Nhit thit k ca phn c gia nhit

(tr trng hp c o hay c tnh ton) (xem ch thch 1 v 2)

1. Bi kh, hi nc hay cht lng Nhit cao nht ca cht gia nhit (ch thch 3)

2. Trc tip bi t chy, khi thi, hay in nng

Vi phn c bo v hay cc phn c gia nhit trc bi dng nhit i lu, nhit cao nht ca cc cht cha trong cc phn cng vi 20C Vi cc phn khng c bo v khi bc x, nhit cao nht ca cht cha trong cc phn cng vi gi tr cao hn gia 50C v 4 x chiu dy phn + 15C, v vi nhit nc thp nht l 150C

3. Gin tip bi in nng, ngha l phn t in cc nm trong nc (ch thch 4)

Nhit cao nht ca mi cht cha trong thit b p lc

4. Bi bc x mt tri khng c phn bo v

a) Trc tip: 50C i vi kim loi; o i vi phi kim loi b) Hi t: nh o c hay tnh ton c

46 CNG BO/S 585 + 586/Ngy 26-9-2013

Ch thch: 1) Phi o c ni no c th vi cc cp nhit nhng v c bo v. 2) Phi tnh d phng cho lng hp th nhit gii hn vi mt s cht lng v

i vi nhng chnh lch c th ca nhit l tng v d do nhng cn tr dng chy trong mt s ng, tn tht qua tm chn, iu kin chy khc thng vi nhin liu v thit b mi, ng cn, s qu la, khi ng nhanh hay ha trn km.

3) Vi cc b trao i nhit kiu ng hoc tm v cc thit b p lc tng t, nhit thp hn c xc nh bi s phn tch truyn nhit c th c s dng cho nhiu b phn khc nhau vi iu kin c tnh d phng i vi s qu nng khi c tn tht hay dng b gii hn ca mi cht lnh.

4) Gi thit cc phn duy tr p sut l hon ton chm trong cht lng v khng c bc x.

1.2.2.2. Nhit thit k cho cc thit b p lc kim loi ph (dng kim loi nhiu lp) hay c lp lt

Nhit thit k cho cc thit b p lc kim loi ph hoc lp lt, khi cc tnh ton thit k da trn chiu dy ca vt liu c s khng bao gm chiu dy ca lp lt hay lp ph, phi c ly nh gi tr p dng cho vt liu c s.

1.2.2.3. S dao ng nhit t cc iu kin thit b p lc thng Khi s dao ng nhit trong iu kin thit b p lc thng xy ra, nhit

thit k khng cn phi iu chnh vi iu kin: a) Nhit nm trong gii hn mi (tc l ti nhit m ni ng

sut gy ra nt v hay 1% sc cng trong 100 000 gi l ng sut xc nh sc bn thit k);

b) Nhit ca thit b chu p lc trong bt k nm vn hnh no s khng vt qu nhit thit k;

c) Nhng dao ng thit b p lc thng v nhit s khng lm cho nhit vn hnh vt qu nhit thit k 15C;

d) Vi cc b phn thp, s dao ng bt thng v nhit s khng lm cho nhit vn hnh vt qu nhit thit k hn 20oC trong nhiu nht l 400 gi trong 1 nm hay 35oC trong nhiu nht 80 gi trong 1 nm.

Khi nhit cao nht vt qu cc gii hn ny, nhit thit k phi c tng ln bng phn vt qu .

Khi nhit vt qu c kh nng vt trn nhit trong d) trong hn 50% thi gian ghi trong , th phi lp thit b ghi nhit .

CNG BO/S 585 + 586/Ngy 26-9-2013 47

1.2.2.4. Nhit lm vic cao nht cho thit b p lc cha kh ha lng Nhit lm vic cao nht phi ly bng gi tr ln hn trong cc gi tr sau: a) Nhit ln nht theo mi cht cha phi chu bi qu trnh cng ngh

di iu kin hot ng khc nghit nht. b) Nhit cao nht m cht lng cha bn trong c th t c do iu kin

mi trng. 1.2.3. n mn 1.2.3.1. Tng qut Mi thit b p lc hay b phn thit b p lc c th b n mn phi c d

phng chng n mn m bo trnh phi gim p sut lm vic, sa cha hay thay th thm. Vic d phng ny c th bao gm:

a) Tng mt cch hp l chiu dy vt liu so vi chiu dy xc nh c bi cc cng thc thit k bao gm c s n mn chung (iu ny c th khng p dng c khi c n mn cc b);

b) Lt hoc bc; c) Bo v bng ca tt; d) X l ha hc cho mi cht cha bn trong; e) X l nhit sau khi hn trnh n mn ng sut; hay f) Kt hp cc phng php trn hoc cc phng php thch hp khc. Khi nh hng n mn c bit l khng ng k hay hon ton khng tn ti,

th khng cn d phng na. 1.2.3.2. B sung do n mn Khi d phng n mn, chiu dy tnh ton ti thiu s c tng ln mt lng

tng ng vi s mt mt chiu dy thnh d kin. Cc k hiu kch thc v chiu dy c s dng tt c cc cng thc thit

k trong quy chun ny th hin cc kch thc trong iu kin b n mn. S n mn c th xy ra trn c hai pha ca thnh trong mt s thit b p lc

v i hi b sung do n mn c hai pha. B sung do n mn khng cn ging nhau cho tt c cc phn ca thit b p lc khi mc tc ng c d kin khc nhau.

Trong qu trnh la chn b sung do n mn, cn xem xt kiu hao ht, ngha l hao ht tng qut, hao ht kiu r hay kiu vt ct.

1.2.3.3. S n mn ca kim loi khng cng loi Khi cc kim loi khng ging nhau (khng cng loi) c s dng cng nhau

trong mi trng n mn, vic kim sot tc ng in ha bng quy trnh thit k chun xc phi c t ra. iu ny c bit quan trng i vi nhm.

48 CNG BO/S 585 + 586/Ngy 26-9-2013

1.2.3.4. Cc lp lt Cc thit b p lc c th c lt ton b hoc mt phn bng vt liu chu

n mn. Vt liu nh vy c th ri, hn khng lin tc, bao ph hon ton, phun hay hn b mt. Cc thc hin d phng c bit i vi vic lt men dng thy tinh.

Khi cc lp lt nh vy ngn cn mt cch hiu qu s tip xc gia cht gy n mn v vt liu c bn ca thit b p lc, th trong thi gian hot ng ca thit b p lc, khng cn b sung do n mn na. Thng thng, cc lp lt nh vy s bao gm lp ph kim loi, lp lt kim loi s dng, lt thy tinh v lp lt nha hay cao su dy. Cc lp sn, m km nhng, m in v kim loi phun ph l khng tnh n tr khi c s tha thun c bit gia cc bn lin quan.

Khi s n mn ca vt liu ph hay lt c th xy ra, chiu dy lp ph v lp lt phi tng ln mt lng cho php tui th phc v ca thit b p lc t c theo yu cu.

1.3. Chiu dy ca thnh thit b p lc 1.3.1. Chiu dy ti thiu tnh ton Chiu dy c quy nh theo cc yu cu trong iu ny l chiu dy cn

thit chu c p sut tnh ton v khi cn thit th phi c b sung ph hp vi chiu dy cho php v d phng cho bt k ti trng thit k no vi chiu dy nh mc nh nht ca cc b phn chu p lc.

Cc k hiu kch thc s dng trong tt c cc cng thc thit k th hin cc kch thc trong iu kin b n mn, tr khi c ch thch.

1.3.2. Chiu dy cho php Chiu dy thc t ti bt k phn no ca thit b p lc hon chnh phi

khng nh hn chiu dy ti thiu tnh ton cng thm cc h s gia tng sau y: (a) Chiu dy b sung cho n mn. (b) Chiu dy b sung, ngoi phn tnh ton chu p lc v n mn,

cung cp cng vng cn thit cho php bc xp v vn chuyn thit b p lc v duy tr hnh dng ca n trong iu kin p sut kh quyn hoc iu kin p lc gim.

1.3.3. Chiu dy nh mc nh nht ca cc b phn chu p lc Ngoi cc yu cu v chiu dy ti thiu tnh ton v chiu dy cho php,

chiu dy nh mc nh nht ca cc b phn chu p lc phi tun th Bng 2.

CNG BO/S 585 + 586/Ngy 26-9-2013 49

Bng 2. Chiu dy nh mc nh nht ca cc b phn chu p lc

Chiu dy nh mc nh nht i vi kiu ch to (xem ch thch 1 v 2) (mm)

Thit b p lc cu to bng kim loi

ng knh ngoi ca b phn thit b p lc (Do)

mm

Rn; kim loi v hn h

quang chm; hn GMAW

Hn vy cng; hn GTAW; v ng trao i

nhit

c

Tt c 225

> 225 1000 > 1000

2,0 2,3 2,4

0,10Do 1,5 2,4

4 8

10 Cha cht nguy him Hai ln gi tr pha trn Cc b phn nhnh ca thit b p lc Xem Chng 2

Cc thit b p lc di ng (vn chuyn c) Xem Chng 4

Lu : 1. Cc gi tr trc tin da trn c s gii hn v ch to, lp rp v kh nng chu bc xp, vn chuyn, lp t v s dng c kim chng. 2. Chiu dy ti thiu bng tng chiu dy i vi thit b p lc lm bng kim loi ph hon ton (kim loi nhiu lp) v bng chiu dy vt liu c bn i vi cc thit b p lc lt.

2. Quy nh v ch to thit b p lc 2.1. Quy nh chung Vic tun th nhng yu cu ti thiu v ch to nhm bo v con ngi v

ti sn. Ngi thit k phi xc nh cc nguy him trong vn hnh v phi tnh n hu qu ca vic h hng thit b p lc, nh gi nhng ri ro pht sinh t nhng s h hng . Vic ny phi bao gm cn nhc mt trong cc kha cnh sau:

a) S thch hp ca vt liu, thit k, ch to, vn hnh v bo dng; b) c tnh ca cc iu kin lm vic; c) Nng lng p sut (p sut v th tch) ca thit b p lc; d) c tnh t nhin ca mi cht bn trong thit b p lc khi b thot ra; e) V tr ca thit b p lc tng ng vi nhn lc, c s v iu kin di chuyn; f) Trong trng hp cn thit phi cn nhc thm tnh kinh t ca vic sa

cha, thay th v s li thi.

50 CNG BO/S 585 + 586/Ngy 26-9-2013

2.2. Nng lc ca ngi ch to Phi c nng lc, bao gm c trang thit b, c s vt cht v nhn lc c

trnh chuyn mn p ng nhu cu sn xut, ch to, hon ci, phc hi v sa cha thit b p lc.

Phi m bo tiu chun cht lng, an ton k thut v phng nga nhim mi trng khi tin hnh sn xut, ch to, hon ci, phc hi v sa cha thit b p lc. i vi cc thit b p lc sn xut mi, hon ci v phc hi phi tun th ng thit k c thm nh.

Chu s kim tra gim st ca ng kim v cht lng, an ton k thut v phng nga nhim mi trng trong qu trnh sn xut mi, hon ci, phc hi v sa cha thit b p lc.

Ngi mua c th yu cu ngi ch to chng minh s ph hp ca c s v nhn lc cho vic ch to trc khi chp nhn ngi ch to thc hin sn xut cc thit b p lc trong phm vi ca Quy chun ny.

C s ch to thit b p lc v nhn vin ca c s ny phi c nng lc v c ng kim nh gi, cp giy chng nhn.

2.3. Nhn hiu, k hiu Cc thit b p lc sau khi c chng nhn c gn nhn hiu ca c s ch

to v tr thun li d thy v c cc ni dung sau: - Tn c s ch to; - Nm sn xut; - Dung tch thit k; - K hiu v nhn hiu; - Du hiu nhn bit ca c quan kim tra. 3. Quy nh chung v vt liu ch to thit b p lc 3.1. Quy nh chung 3.1.1. Vt liu s dng ch to thit b chu p lc phi ph hp thit k c

thm nh, vi iu kin lm vic ca chng v tham chiu cc yu cu ca tiu chun tng ng nh TCVN, AS, BS, ASME... v thit b p lc.

3.1.2. C s ch to phi trnh cc ti liu sau v vt liu cho ng kim trc khi a vt liu vo s dng:

Chng ch xc nhn cht lng, c tnh ca vt liu bng bn gc hoc bn sao c xc nhn sao y bn chnh. Khi khng c cc vn bn trn th c s ch to phi tin hnh kim tra th nghim vt liu trc khi a vo ch to.

CNG BO/S 585 + 586/Ngy 26-9-2013 51

Khi khng c cc vn bn trn th c s ch to phi tin hnh kim tra th nghim vt liu vi cc ch tiu phi kim tra l:

a) Thnh phn nguyn t kim loi v i chiu vi m hiu kim loi tng ng; b) Gii hn bn, gii hn chy v cc ch tiu cn thit khc phc v cho ch to,

lp h s. Th vt liu c thc hin ti c s th nghim (phng th nghim, trm th)

c trang thit b v c cn b chuyn mn ph hp c ng kim chng nhn. 3.2. Cc vt liu phi kim loi Cc giong, m hoc cc b phn tng t bng vt liu phi kim loi s dng

cho cc ng dng nhit thp phi thch hp vi ng dng ti nhit lm vic nh nht (MOT) v phi tnh n kh nng b ha cng hoc ha gin.

4. Quy nh chung v hn v kim tra khng ph hy (NDT) 4.1. Quy nh chung 4.1.1. Cc yu cu v hn, kim tra cht lng hn trong ch to thit b p lc

phi ph hp thit k c thm nh v quy nh ca cc tiu chun TCVN, ISO, AS, ASNT-SNT, AWS, ASME... tng ng.

4.1.2. Hn phi c thc hin theo quy trnh hn, vt liu hn (que hn, dy hn, kh hn, thuc hn...) c ng kim chng nhn.

4.1.3. Kiu mi hn, kch thc v gia cng vt mp ca ng hn phi c nu r trn cc bn v v quy trnh hn.

4.1.3. Cht lng cc ng hn thit b p lc sau khi hn xong phi c kim tra v th bng phng php kim tra NDT, th v kim tra kh nng chu p lc, th kn... theo quy nh.

4.1.4. Cc th hn, gim st vin hn, nhn vin kim tra NDT, th v kim tra kh nng chu p lc, th kn p lc... ca cc c s th nghim phi qua o to v c ng kim cp giy chng nhn hoc c s c ng kim chp nhn ph hp vi quy nh ca cc tiu chun TCVN, ISO, ASNT-SNT, AWS, ASME... tng ng.

4.2. Cc loi mi hn Trong quy chun ny, ty thuc v tr ca chng, cc mi hn c phn loi

theo mt trong cc mi hn c trng chnh sau: 4.2.1. Loi A, mi hn dc: nhng mi hn dc trn thn tr chnh, on

chuyn tip ng knh (on cn), hoc trn cc b phn nhnh; hay nhng mi ni ti cc v tr yu cu mi hn tng ng. Cc mi hn ny bao gm cc mi hn trn cc y cong v phng, hoc mi hn ni y cu vi thn

52 CNG BO/S 585 + 586/Ngy 26-9-2013 chnh, hoc trn cc tm phng s dng to hnh (p, mit...) cc b phn ca thit b p lc.

4.2.2. Loi B, mi hn theo chu vi: nhng mi hn theo chu vi trn cc thn tr chnh, trn cc on chuyn tip ng knh (on cn), hoc trn cc b phn nhnh; hay nhng mi hn theo chu vi ni y cong hoc ni on chuyn tip vi thn chnh.

4.2.3. Loi C, mi hn gc: nhng mi hn vng quanh ti gc ca b phn chu p lc nh cc mi ni bch, mi ni mt sng hay cc y phng vi thn chnh, vi y cong, vi on chuyn tip ng knh (on cn) hay vi cc b phn nhnh.

4.2.4. Loi D, mi hn nhnh: nhng mi hn ni cc b phn nhnh vi thn chnh, vi on cn hoc vi y.

4.2.5. Nhng kiu mi hn ca mi hn gip mp: i) Mi hn gip mp hai pha; ii) Mi hn gip mp mt pha.

Hnh 1. Cc kiu mi hn - da vo v tr

4.3. S lng mi hn S lng mi hn trn thit b p lc phi l ti thiu c th. 4.4. V tr ca cc mi hn Cc mi hn cn phi nh v sao cho: a) Trnh nhiu lon n dng lc hoc thay i t ngt cng vng hoc

cc vng tp trung ng sut cao, c bit l cc thit b p lc chu cc ti trng thay i bt thng hoc va p;

CNG BO/S 585 + 586/Ngy 26-9-2013 53

b) Trnh nhng vng c kh nng b n mn trm trng; c) Trnh trng hp c qu hai mi hn giao nhau ti mt im; d) Khong cch gia cc chn ca mi hn cc chi tit gn vo thit b p lc,

chn ca cc mi hn gc ca b phn nhnh hoc ng ct, hoc cc mi hn chnh cha x l khng c nh hn 40mm hoc ba ln chiu dy thn;

e) To iu kin hp l cc thit b hn v th hn tip cn, v c th kim tra bng mt, chp X quang hoc siu m ca pha chn cc mi hn gip mp;

f) Mi hn c th nhn thy ngay trong qu trnh s dng (sau khi g b lp bo n, cch nhit nu cn thit) v trnh xa cc kt cu .

4.5. Thit k cc mi hn chnh 4.5.1. Yu cu chung Cc kiu mi hn phi ph hp c th chuyn mi ti trng gia nhng

phn c ni. Chun b mp mi hn phi m bo hn tt, ngu v thu hon ton ph hp

vi cc quy trnh hn c th. 4.5.2. Hn gip mp Chiu dy chn (ngoi tr phn nh ln hay phn d kim loi hn bn trn b

mt vt liu c bn) ca cc mi hn dc v mi hn theo chu vi trn thn, y hoc cc b phn nhnh, phi t nht bng chiu dy ca phn mng hn c ni.

4.5.3. Hn gc Khng cho php hn gc theo chu vi, ngoi tr nh m t trong Hnh 2(a) v

Bng 3, khi cc kch thc phi tng bn cn thit i vi h s bn mi hn thch hp.

Ti trng cho php trn cc mi hn gc khc phi cn c vo tit din chn thit k nh nht ca mi hn khi s dng mt bn thit k khng ln hn 50% ca bn thit k f, cho vt liu yu hn trong mi ni.

Tit din chn mi hn thit k ti thiu phi c ly theo chiu dy thit k chn mi hn cho php gim bt chiu dy chn do khe h, nhn vi chiu di hu hiu ca mi hn bng chiu di o c ti ng tm ca chn. Khng c mi hn gc no c php c chiu di mi hn hu hiu nh hn 50mm hay 6 ln chiu di ca chn, ty theo gi tr no nh hn.

Hnh dng ca mi hn gc phi ph hp vi Hnh 2. i vi cc mi hn gc ti cc gc hoc cc b phn nhnh v cc mi hn

chu ng sut un khc. Cc tm mng ca cc mi hn gc chng mp phi c chng nhau t nht 4 ln

b dy ca tm mng hn, ngoi tr cc y cong hn chng mp.

54 CNG BO/S 585 + 586/Ngy 26-9-2013

Ch thch: L1 Chiu cao hu hiu ca chn trn mt ng; L2 Chiu cao hu hiu ca chn trn mt ngang; T Chiu dy thit k ca gc mi hn (0,71 L1 i vi mi hn cn); Khe h = 1,5mm hoc L1/8, ly gi tr nh hn: Phn li: Ti thiu = 0; Ti a = 1,5mm + L1/8, hoc 4mm, ly gi tr nh hn.

Hnh 2. Hnh dng mi hn gc v cc kch thc

4.5.4. Chun b mi hn Khi yu cu chun b mi hn th quy trnh hn phi c th, kim tra v

ph duyt. 4.5.5. p dng cc mi hn Vic p dng cc kiu khc nhau ca mi hn dc v hn theo chu vi phi ph

hp vi Bng 3. Hn gip mp c s dng tm lt c gi li trong khi hot ng, hoc mi

hn chng mp mt pha khng c s dng ni c th xut hin s n mn qu mc hoc chu mi do cc ti trng thay i bt thng hoc ti trng va p.

4.5.6. H s bn mi hn, H s bn mi hn cho php ln nht ca cc mi hn phi theo Bng 3. 4.5.7. Nhn lc hn 4.5.7.1. Nng lc ca gim st vin hn Tt c vic hn phi c tin hnh di s gim st ca ngi c o to

ph hp v c kinh nghim v ch to v cng ngh hn c s dng cho thit b p lc, ngoi tr khi c tha thun khc.

Gim st vin phi c chng ch gim st hn c trnh chuyn mn v kinh nghim khc c ng kim chng nhn hoc chp nhn.

CNG BO/S 585 + 586/Ngy 26-9-2013 55

4.5.7.2. Nng lc ca th hn Mi th hn hn thit b p lc v cc b phn chu p lc phi p ng cc

yu cu sau: (a) c o to hoc c kinh nghim v hn cc quy trnh hn c th c

s dng; (b) c ng kim cp giy chng nhn hoc chp nhn. 4.6. Kim tra khng ph hy (NDT) vt liu v hn Vt liu trc khi ch to v khi c yu cu tng cng s m bo cht

lng v vt liu nh vt liu ch to mt sng hay cc b phn chnh ca cc thit b p lc, kim tra khng ph hy (NDT) phi c thc hin trc khi gia cng.

Cht lng cc mi hn phi c kim tra bng cc phng php kim tra khng ph hy (NDT) tng ng.

Cc phng php kim tra khng ph hy chnh bao gm: a) Kim tra bng mt (VT); b) Kim tra bng chp tia bc x X Ray hoc gama (RT); c) Kim tra bng siu m (UT); d) Kim tra t tnh (MT); e) Kim tra bng thm thu (PT). Cc yu cu v kim tra vt liu, cht lng cc mi hn bng phng php

khng ph hy (NDT) ph hp vi yu cu ca cc tiu chun TCVN, ISO, ASNTSNT, AWS, ASME - Boiler and Pressure Vessel Code - Phn V (Nondestructive Examination)... tng ng.

4.7. Kim tra, chng nhn th hn, gim st vin hn Th hn, gim st vin hn, nhn vin kim tra bng cc phng php ph hy

(DT), khng ph hy (NDT), phn tch thnh phn ha hc, th, kim tra kh nng chu p lc, th ti, th kn p lc... phi c ng kim chng nhn hoc chp nhn theo yu cu quy nh ca Quy chun ny.

4.7.1. Cc loi hnh kim tra, chng nhn - Kim tra cp giy chng nhn ln u; - Kim tra, xc nhn hng nm giy chng nhn; - Kim tra, cp mi giy chng nhn. 4.7.2. Thc hin vic nh gi a) Vic kim tra, cp giy chng nhn thc hin theo yu cu quy nh ca quy

chun, tiu chun p dng.

56 CNG BO/S 585 + 586/Ngy 26-9-2013

b) T chc, c nhn c yu cu chng nhn gi ngh cho ng kim. c) T chc, c nhn ngh cp giy chng nhn chu trch nhim thc hin

cc cng vic cn thit cho vic kim tra, chng nhn. 4.7.3. Cp giy chng nhn Sau khi kt thc qu trnh kim tra, c nhn kim tra t cc yu cu quy nh,

ng kim s cp giy chng nhn cho c nhn theo quy nh ph hp vi quy chun, tiu chun p dng.

Bng 3. H s bn mi hn

H s bn mi hn ln nht i vi thit b p

lc (Ch thch 4) Kiu mi hn

V tr mi ni c

php (Xem hnh 1)

Gii hn mi ni(Ch thch 2)

Kim tra bng tia X hoc siu

m (Ch thch)

Loi 1

Loi 2

Loi 2B

Loi 3

Mi hn gip mp 2 pha, hoc mi hn gip mp khc c cht lng tng ng (khng bao gm cc mi hn c s dng tm lt c gi li khi hot ng)

A, B, C, D Khng c

Ton b im

Khng

1,0 _ _

_

0,85 _

_ _

0,80

_ _

0,70

Mi hn gip mp 1 pha vi ming lt c gi li khi hot ng

A, B, C, D

Mi hn theo chu vi - khng c gii hn, ngoi tr t 16mm i vi mi hn vi g ni Mi hn dc - gii hn ti t 16mm

Ton b im

Khng

0,90 _ _

_

0,80 _

_ _

0,75

_ _

0,65

Mi hn gip mp 1 pha khng s dng tm lt

B, C

Ch cho mi hn theo chu vi trong thit b p lc loi 2 v 3 (xem TCVN 8366:2010) vi t 16mm v ng knh trong ti a

Khng _ 0,70 0,65 0,6

CNG BO/S 585 + 586/Ngy 26-9-2013 57

H s bn mi hn ln nht i vi thit b p

lc (Ch thch 4) Kiu mi hn

V tr mi ni c

php (Xem hnh 1)

Gii hn mi ni(Ch thch 2)

Kim tra bng tia X hoc siu

m (Ch thch)

Loi 1

Loi 2

Loi 2B

Loi 3

Mi chng mp c hn gc kn 2 pha

A, B, C

Ch cho mi hn theo chu vi trong thit b p lc loi 3 (xem TCVN 8366:2010). Cc mi hn dc trong thit b p lc loi 3 ch vi t 10mm

Khng _ _ _ 0,55

Mi chng mp c hn gc kn 1 pha vi hn nt

B

Ch cho mi hn theo chu vi trong thit b p lc loi 3 (xem TCVN 8366:2010) ni y chm vi thn c ng knh trong ti a 610mm

Khng _ _ _ 0,50

Mi chng mp c hn gc kn mt pha khng c hn nt

B

Ch cho mi hn theo chu vi trong thit b p lc loi 3 (xem TCVN 8366:2010) ni (a) y li v pha p lc, vi thn bng mi hn gc pha bn trong ca thn c t 16mm (b) y lm v pha p lc, vi thn c chiu dy t 8mm, ng knh trong ti a 610mm bng mi hn gc trn vai ca y

Khng _ _ _ 0,45

58 CNG BO/S 585 + 586/Ngy 26-9-2013

H s bn mi hn ln nht i vi thit b p

lc (Ch thch 4) Kiu mi hn

V tr mi ni c

php (Xem hnh 1)

Gii hn mi ni(Ch thch 2)

Kim tra bng tia X hoc siu

m (Ch thch)

Loi 1

Loi 2

Loi 2B

Loi 3

Mi hn trong ng v ng dn A, B

i vi cc mi hn dc trong cc ng thp hp kim cao, h s bn mi hn c bao gm trong bn thit k. i vi cc ng thp ccbon, cc bon - mangan v hp kim, phi s dng h s bn mi hn i vi mi hn dc

Ch thch: 1. Vic kim tra c lit k l cho kiu mi hn A v B. 2. t l chiu dy nh mc ca thn. 3. Cc h s ny p dng cho kiu hn dc v hn theo chu vi. 4. H s bn mi hn bng 1,0 c p dng khi thit k: a) Nhng sn phm khng hn, nh cc ng khng hn v cc sn phm rn; b) Mi hn gip mp kiu dc v theo chu vi, v hn gc gn cc y, ch

i vi cc thit b p lc chn khng.

Chng 2 CC THIT B P LC V B PHN CHI TIT

1. Thn hnh tr v thn hnh cu chu p lc trong v ti trng kt hp 1.1. Quy nh chung: a) Chiu dy ti thiu phi khng nh hn cc gi tr c xc nh trong

Quy chun ny. b) K hiu Trong iu ny, s dng cc k hiu sau: D ng knh trong ca thn, tnh bng milimt;

Dm = oD + D

2 ng knh trung bnh ca thn, tnh bng milimt;

Do ng knh ngoi ca thn, tnh bng milimt; E m un n hi ti nhit thit k, tnh bng megapascal; f bn ko thit k ti nhit thit k, tnh bng megapascal; fa = f ti nhit th, tnh bng megamascal; M m men un dc, tnh bng niuton milimt;

CNG BO/S 585 + 586/Ngy 26-9-2013 59

P, Ph p sut tnh ton P, hoc p sut chu th thy lc Ph, ty trng hp tng thch, tnh bng megapascal;

Q m men xon quanh trc bnh, tnh bng N/mm; SE ng sut tng ng trong bnh (c s ng sut ct cc i), tnh bng

megapascal; Sh ng sut vnh trong bnh, tnh bng megapascal; Sl ng sut dc trong bnh, tnh bng megapascal; Ss ng sut ct trong bnh, tnh bng megapascal; W ch vi bnh thng ng H s bn mi hn hoc h s lm yu do khot l, ly theo gi tr nh nht; Aa Sc cng theo chu vi ca thn hay cn; Aa Sc cng theo chu vi ca vng tng cng; As Din tch mt ct ngang ca vng tng cng, tnh bng milimt vung; Ba ng sut on l thuyt ca vng tng cng, tnh bng megapascal; D Chiu cao hng tm ca chi tit tng cng (gia cc bch, nu c), tnh

bng milimt; D ng knh trong ca thn, tnh bng milimt; Dm ng knh trung bnh ca thn, tnh bng milimt

= Do - t; Do ng knh ngoi ca thn trong iu kin b n mn ton b, tnh bng

milimt; E M un n hi Young ca thn, cn hoc b phn tng cng ti nhit

thit k, tnh bng megapascal; f bn thit k ca thn hay cn ti nhit thit k, tnh bng megapascal; Ic M men th cp cn thit ca din tch vng tng cng/thn kt hp trn

mt ct vung gc vi thn v i vi trc trung ha ca n song song vi trc ca thn hnh tr, tnh bng milimt m bn (mm4);

Ir M men th cp cn thit ca din tch vng tng cng trn mt ct vung gc vi thn v i vi trc trung ha ca n song song vi trc ca thn hnh tr, tnh bng milimt m bn (mm4);

L Chiu di hiu dng ca thn hnh tr, tnh bng milimt; L' Chiu di ca thn c th bao gm tnh ton ca m men th cp ca din

tch c cung cp bi cc vng tng cng, tnh bng milimt = (Dmt)1/2, hoc Ls, ly gi tr nh hn;

60 CNG BO/S 585 + 586/Ngy 26-9-2013

Ls Tng ca cc na khong cch t vng tng cng ti cc vng trn cnh kia (i vi cc vng cch u Ls = L), tnh bng milimt;

n S lng cc gn theo chiu chu vi; P p sut tnh ton (tc l p sut thc bn ngoi), tnh bng megapascal; Pe p sut l thuyt cn thit gy ra on n hi ca thn, tnh bng

megapascal; Py p sut l thuyt cn thit gy ra vng do ca thn, tnh bng

megapascal; V Ti trng ct hng tm, tnh bng niuton; Q M men s cp ca din tch i vi ng trung ha ca b phn ca

thn, v b phn c dng nh mt phn ca vng tng cng, tnh bng milimt khi;

t chiu dy tnh ton ti thiu ca b phn chu p lc (khng bao gm cc phn b sung chiu dy, tnh bng milimt;

T chiu dy thc (ly nh chiu dy danh ngha tr i phn gim khi gia cng), tnh bng mt;

tf Chiu dy ca vnh tng cng, tnh bng milimt; tw Chiu dy ca gn tng cng, tnh bng milimt; Y Gii hn chy danh ngha nh nht (ng sut ko 0,2%) ti nhit thit k,

tnh bng megapascal, nu gi tr khng c sn, Y c th ly bng: 1,5f cho thp cc bon, thp hp kim thp v thp ferit; 1,1f cho thp austenit v kim loi mu.

Z = ;2LD

Na gc nh ca y cn hoc cn thu, tnh bng ; Chiu di bc sng, tnh bng milimt; w Chiu rng phn cha ra ca vnh tng cng tnh t tm ca gn, tnh bng

milimt. 1.2. Thn hnh tr Chiu dy tnh ton ti thiu ca thn hnh tr phi bng gi tr ln hn trong

cc chiu dy c xc nh t cc cng thc sau: (a) Da vo ng sut theo chu vi (cc mi hn dc)

t = 2 2

mPDPDf P f = hoc P =

2 f tD t+ (1)

CNG BO/S 585 + 586/Ngy 26-9-2013 61

b) Da vo ng sut dc (cc mi hn theo chu vi)

t = 4 4

mPDPDf P f = hoc P =

4 f tD t+ (2)

1.3. Thn hnh cu Chiu dy tnh ton ti thiu ca thn hnh cu phi c xc nh t cng

thc sau:

t = PD4f - 0.4P

hoc P = 4ft

D + 0.4t (3)

2. y cn v on cn chu p sut trong 2.1. Yu cu chung y cn hoc on cn chu p sut trong phi c thit k theo quy nh ca

mc ny. y cn v on cn c th c cu to t nhiu on c chiu dy gim dn c xc nh bi cc ng knh gim dn tng ng.

2.2. Nhng k hiu Nhng k hiu sau y c dng trong mc ny: D1 ng knh trong ca on cn hoc y cn ti v tr xem xt, tc l D1 c

th bin thin trong khong Ds v DL (xem Hnh 4), tnh bng milimt. DmL ng knh trung bnh ca y cn hoc on cn ti y ln, tnh bng

milimt. = DL + t (xem Hnh 4).

f Sc bn ko thit k ti nhit tnh ton, tnh bng megapascal. P p sut tnh ton, tnh bng megapascal. rL Bn knh trong ca vai (on un chuyn tip) ti phn tr ln hn, tnh

bng milimt. rs Bn knh trong ca vai (on un chuyn tip) ti phn tr nh hn, tnh

bng milimt. t Chiu dy tnh c ti thiu ca y cn hoc on cn (khng tnh phn b

sung chiu dy, tnh bng milimt. Gc thu ca y cn hoc on cn (tnh ti im xem xt) so vi trc ca

bnh (xem Hnh 4), tnh bng . Lu : i vi cn lch, s dng gc ln hn. H s bn thp nht ca mi ch ni trong y cn v on cn i vi

nhng mi ghp ni)

62 CNG BO/S 585 + 586/Ngy 26-9-2013

Hnh 4. y cn v on cn

2.3. on cn Chiu dy tnh ton nh nht ca on cn c xc nh bi:

t = 1 12 os

PD xf P c (4)

hoc P = 1

2 coscos

f tD t

+ (5)

2.4. Ghp cn vo thn tr (a) Nn dng vai cn (on cong chuyn tip) gia on cn v on tr v

phi dng khi gc ln hn 30o. (b) Khi gc khng ln hn 30o th on cn c th ni vi on tr m

khng cn vai cn vi iu kin mi ni l hn gip mp 2 pha. 3. y cn v on cn chu p sut ngoi Chiu dy tnh ton nh nht ca y cn hoc on cn chu p sut ngoi,

hoc khng hn hoc c hn gip mp, c xc nh c cc kch thc tng ng sau y:

(a) Chiu di tng ng L ca thn tr = chiu di o xin theo mt cn.

Gia cng khi cn thit

x

CNG BO/S 585 + 586/Ngy 26-9-2013 63

(b) ng knh trung bnh tng ng Dm ca tr: (i) khi chiu di o xin ca cn 3(DmLt/cos)0,5:

Dm = DmL/cos (6) (ii) khi chiu di o xin ca cn > 3(DmLt/cos)0,5:

Dm = 0,5

mL mLD - 1,1(D t/cos)cos

(7)

4. y cong chu p sut trong 4.1. Yu cu chung Cc y cong khng c ging c dng cu, elip, chm cu... chu p sut

trong (tc l p sut tc dng ln mt lm) phi c dng cu hoc elip. 4.2. Ch thch t Chiu dy tnh ton nh nht ca y im mng nht sau khi gia cng

(khng tnh phn b sung chiu dy), tnh bng milimt; P p sut tnh ton, tnh bng megapascal; D ng knh trong ca y, tnh bng milimt; Do ng knh ngoi ca y, tnh bng milimt; R Bn knh trong ca mt cu hoc chm ca y, tnh bng milimt; Ro Bn knh ngoi ca mt cu hoc chm ca y, tnh bng milimt; r Bn knh trong ca vai y, tnh bng milimt; H s bn nh nht ca bt k mi hn no trn y, bao gm c mi ni

thn vi y trong trng hp y khng c on mp tr. = 1 i vi y lm t 1 tm (khng ghp) v c on mp tr.

f bn ko nhit thit k, tnh bng megapascal; h Na chiu di trc nh pha trong ca y elip, hoc chiu su pha trong ca

y chm cu c o t ng tip tuyn, trong iu kin b n mn hon ton, tnh bng milimt;

ho Na chiu di trc nh pha ngoi ca y elip c o t ng tip tuyn, tnh bng milimt;

k H s trong cng thc dnh cho cc y elip, ph thuc vo t l D/2h ca y

= 21 2

6 2Dh

+ (xem Bng 4);

M H s trong cng thc dnh cho y chm cu, ph thuc vo t l R/r ca y

= 1/ 21 3

4Rr

+ (xem Bng 5).

64 CNG BO/S 585 + 586/Ngy 26-9-2013

4.3. Cc gii hn bin dng Bin dng ca cc kiu y tiu biu c ch ra trn Hnh 5. Bn knh trong ca phn chm y cong khng c ging phi khng ln hn

ng knh ngoi ca y ti ng tip tuyn. Phi xem xt n kh nng bin dng do ng sut cc b cao trong khi th

thy lc. c bit ch khi cc gii hn sau b t n hoc b vt qua: a) Vi cc y elip: D/t 600; b) Vi cc y chm cu c bn knh vai t ti gi tr nh nht cho php (6%

bn knh chm): D/t > 100 hay P 690 kPa.

Khi y c gia cng to hnh c mt vng b mt phng, th ng knh vng trn gi nh ca vng phng khng c vt qu ng knh gi nh cho php ca y phng khng ging s dng K = 5.

Lu : Vi cc y chm cu c D/tk > 300, khuyn co:

0,84

1,53 1,1

150

k

rP Df D R

t D

=

Trong : tk: Chiu dy nh nht ca vai y trong iu kin b n mn hon ton, tnh

bng milimt; Cng thc ny p dng di gii hn do

Hnh 5. Kch thc ca cc y

CNG BO/S 585 + 586/Ngy 26-9-2013 65

4.4. Chiu dy y 4.4.1. y elip Chiu dy tnh ton nh nht ca cc y elip, c hoc khng c khot l, phi

c xc nh bi cng thc sau:

t = 2 0, 2

PDKf P (8)

4.4.2. y chm cu Chiu dy tnh ton nh nht ca cc y chm cu, c hoc khng c khot l,

phi c xc nh bi phng trnh sau:

t = 2 0, 2

PRMf P (9) Bng 4. Cc gi tr ca h s K

(Tra theo gi tr gn nht ca D/2h, khng cn thit phi ni suy) D2h

K

3,0

1,83

2,9

1,73

2,8

1,64

2,7

1,55

2,6

1,46

2,5

1,37

2,4

1,29

2,3

1,21

2,2

1,14

2,1

1,07

2,0*

1,00D2h

K

1,9

0,93

1,8

0,87

1,7

0,81

1,6

0,76

1,5

0,71

1,4

0,66

1,3

0,61

1,2

0,57

1,1

0,50

1,0

0,50

* Thng xem nh y elip 2:1 Bng 5. Cc gi tr ca h s M

(Tra theo gi tr gn nht ca R/r, khng cn thit phi ni suy)

Rm

M

1,0

1,00

1,25

1,03

1,50

1,06

1,75

1,08

2,00

1,10

2,25

1,13

2,50

1,15

2,75

1,17

3,00

1,18 Rm

M

3,25

1,20

3,50

1,22

4,0

1,25

4,5

1,28

5,0

1,31

5,5

1,34

6,0

1,36

6,5

1,39

_

_

Rm

M

7,0

1,41

7,5

1,44

8,0

1,46

8,5

1,48

9,0

1,50

9,5

1,52

10,0

1,54

10,5

1,56

_

_

Rm

M

11,0

1,58

11,5

1,60

12,0

1,62

13,0

1,65

14,0

1,69

15,0

1,72

16,0

1,75

16,66*

1,77

_ _

* T s R/r ln nht cho php khi R bng ng knh ngoi (Do) ca y

66 CNG BO/S 585 + 586/Ngy 26-9-2013

4.4.3. y cu Chiu dy nh nht ca cc y cu, c hoc khng c cc khot l, c xc

nh bi phng trnh sau:

t = PR2f - 0,2P

(10)

4.5. Lp y Cc y c lp bng phng php hn phi tun theo Hnh 6.

thn

Hnh 6. Mi ghp ca cc y cong

CNG BO/S 585 + 586/Ngy 26-9-2013 67

Hnh 6. Mi ghp ca cc y cong (Tip theo)

Nh nht

Nh nht

68 CNG BO/S 585 + 586/Ngy 26-9-2013

Hnh 6. Mi ghp ca cc y cong 5. Cc y cong chu p sut ngoi Cc y cong khng gia cng c dng cu, elip, chm cu... chu p sut trong

(tc l p sut tc dng ln mt li). 5.1. y elip Chiu dy tnh ton nh nht ca cc y elip, c ch to nguyn tm hoc

c ghp bng mi hn gip mp, ti bt k im no sau khi gia cng phi c chiu dy ln hn trong cc gi tr c xc nh nh sau:

Chiu dy ca thn hnh cu tng ng c xc nh nh i vi mc thn hnh tr v hnh cu chu p lc ngoi. Gi tr ca Ro phi ly bng ng knh ngoi ca y nhn vi h s c xc nh t cng thc (11) hoc ly t bng sau:

Bng 6. H s xc nh Ro cho cng thc (11)

H s ho/Do 0,167 1,360 0,178 1,270

0,192 1,180

0,208 1,080

0,227 0,990

0,250 0,900

H s ho/Do 0,278 0,810 0,313 0,730

0,357 0,650

0,417 0,570

0,500 0,500

Lu : Cc gi tr gia c th tnh ni suy hoc t cng thc sau:

H s = 0,25 + 0,4 - 0,200 0 0

hh /D D

(11)

Chiu dy t c xc nh ging nh i vi y cong chu p sut trong, vi p sut c gi tr bng 1,67 ln p sut ngoi, s dng h s bn mi hn bng 1.

5.2. y cu v y chm cu Chiu dy tnh ton nh nht ti bt k im no sau khi gia cng ca y cu

hay y chm cu phi l chiu dy ln hn trong cc gi tr c xc nh nh sau:

CNG BO/S 585 + 586/Ngy 26-9-2013 69

(a) Chiu dy ca thn cu tng ng c bn knh ngoi Ro bng bn knh ngoi ca chm y, c xc nh theo mc thn hnh tr v hnh cu chu p lc ngoi.

(b) Chiu dy t c xc nh ging nh i vi y cong chu p sut trong, vi p sut c gi tr bng 1,67 ln p sut ngoi, s dng h s bn mi hn bng 1.

6. Cc kt cu chung Cc kt cu khng chu p lc bn trong v bn ngoi, v cc ph kin gn vo

bnh s c thit k theo thng l v mt k thut v phi c lp t xa nht c th khng to ra bt k ti trng tp trung cc b no ln thnh bnh.

Cc ti trng t cc kt cu, thit b v ph kin c gn vo phi c chu bi cc vnh tng cng hoc cc vnh lt gn trc tip vo cc gi bnh v qua truyn ti mng m khng gy ra ng sut ln thnh bnh hoc y bnh. i vi cc chi tit gn vo bnh c th vn chuyn, xem Chng 4 - Phn II (Bnh c th vn chuyn).

Cc tai mc, cc vnh, cc vu v cc chi tit tng t phi c thit k x c nc t cc chi tit gn vo bnh. Cn trnh cc khoang trng v khe h c th gi cht lng v gy ra n mn.

7. Cc kt cu bn trong Cc kt cu bn trong phi c thit k trnh hng hc khi vn hnh, v

nn t trn nh ca cc gi thay v c treo trn gi . Cc gi v kt cu nh vy phi c lm bng vt liu chu n mn i vi mi trng lm vic, hoc phi c d phng cho n mn ti nhng ch c kh nng b n mn. i vi cc kt cu c th d dng thay th th d phng cho n mn khng cn thit nh d phng i vi bnh.

8. Phng php gn kt chung Cc vu, kp hoc cc gi cho cc kt cu, lp lt, bo n, thit b hot

ng v ng ng c th c gn vo bn trong hoc bn ngoi bnh, min l phi c tnh ton trnh cc ng sut qu mc hoc bin dng thnh bnh trong cc iu kin vn hnh. Cc vu, kp hoc cc gi c hn vo thnh bnh phi c kch c ln ngn nga vt qu ng sut v khng nn ln hn hai ln chiu dy thnh bnh.

Cc cht hn chu lc ch c th c s dng cho cc chi tit khng chu p lc gn vo cc b phn chu p lc v theo s tha thun gia cc bn lin quan.

Cc chi tit c hn vo phi c thit k theo Hnh 7(A) v (B). c bit i vi cc b phn chu p lc, phi l mi hn lin tc.

i vi kt cu s dng kim loi ph (kim loi nhiu lp) khi cc chi tit c gn vo lp ph m khng gn trc tip vo kim loi c bn, th phi chng t c rng lin kt gia lp ph v kim loi c bn l thch hp cho cc ti trng v tun theo cc yu cu khc c lin quan ca tiu chun ny.

70 CNG BO/S 585 + 586/Ngy 26-9-2013

Hnh 7(A). Gn cc vu, tai v gia cng Ch thch: c t khi t bng chiu dy cc thnh phn gn kt

Hnh 8(B). Gn kt cc gi tr rng

CNG BO/S 585 + 586/Ngy 26-9-2013 71

9. Ca kim tra 9.1. Yu cu chung Tt c cc thit b p lc, loi tr cc thit b c cho php khng cn ca

kim tra phi c ca kim tra thch hp cho php kim tra bng mt v lm sch cc b mt bn trong. Khi cn thit th phi c thit b cho php vo c bn trong.

Cc ca chui ngi phi b tr ngi kim tra vo trong mt cch d dng v phi an ton v sn sng a ngi ra.

9.2. Cc thit b thng dng Ngoi cc thit b c th, cc thit b phi c lp cc ca kim tra theo

Bng 7 hoc cc ca phi c b tr cho php kim tra gn vi vng hay b hng nht.

Bng 7. Cc ca kim tra cho cc thit b thng dng

ng knh trong, mm

Kch c khong trng nh nht ca ca (Ch thch 1), mm

S lng ca t nht (Ch thch 2) V tr ca ca

1 i vi cc thn c chiu di 900mm

Trn y, hoc nu khng t c th t trn thn, gn

vi y 315 30 2 i vi cc thn c chiu di > 900mm

> 315 460 40

> 460 920 50 2 i vi thn c chiu di bt k

1 ci trn mi y, hoc nu khng t c th t trn thn, gn vi

mi y Ca th tay 150

hoc 180 x 120

2 i vi cc thn chiu di 3000mm

(Ch thch 3)

1 ci mi y hoc trn thn,

gn vi y > 920 1500 1)

Ca th tay 290 1 i vi cc thn

di 3000mm (Ch thch 3)

Trn on 1/3 thn gia (Ch thch 4)

> 1500 Ca chui ngi elip hoc tng t 2) 1 cho cc ng c chiu di no

Trn thn hoc y d dng vo ra

Lu : 1) C th la chn ca th tay hoc ca th u 2) Xem Bng 9

72 CNG BO/S 585 + 586/Ngy 26-9-2013

Ch thch: 1. Kch thc l khot trn thn ngoi ca bnh 2 v khng c vt qu 65mm. 2. Chiu di ca thn c o gia cc mi hn ni y vi thn tr. 3. i vi cc thn c chiu di ln hn 3000mm, s lng cc ca phi tng

ln sao cho khong cch gia cc ca th tay khng vt qu 2000mm v vi cc ca th u khng qu 3000mm.

4. i vi cc thn c chiu di nh hn 2000mm, c th s dng 1 ca th u trn 1 y.

9.3. Cc thit b khng b mn Cc thit b khng b n mn, mi mn, xm thc bn trong v cc thit b: (a) c s dng cho cc cng dng tnh (v d, t c nh, hoc thng t

c nh v khng thng xuyn c vn chuyn, khng chu va chm mnh hoc cc ti gy mi), v c dung tch khng qu 60m3;

(b) c s dng cho cc cng dng khng tnh, nhng c dung tch cha khng vt qu 5m3 hoc

(c) c t ngm, c dung tch khng qu 15m3, phi c lp vi cc ca kim tra theo Bng 8. Cc thit b vt qua gii hn ca (a) v (b) trn y phi c lp ca chui ngi, tr khi qu trnh cng ngh hoc c tnh ca mi cht hoc thit k bnh cho thy lp ca chui ngi c th gy rc ri. i vi cc thit b c cch nhit bng chn khng, khi c lp ca chui ngi thn trong, nhng khng lp thn ngoi, th ngi ch to phi nh du r rng trn thn ngoi bng dng ch: Ca chui ngi y ti ch i din vi ca chui ngi nm bn trong.

Trong Quy chun ny, cc thit b khng b n mn bao gm cc bnh cha mi cht lnh, cha kh du m ha lng (LPG) v nhng cht khc m qua th nghim hoc qua thc t cho thy chng khng gy tc ng c hi ln vt liu ch to ra chng.

Bng 8. Cc ca kim tra trong cc thit b khng chu n mn

ng knh trong (mm)

Kch thc nh nht ca ca mm (Ch thch 2 v 3)

S lng ca t nht v v tr cc ca (Ch thch 1)

160 Khng yu cu - > 160 250 25

> 250 400 30

> 400 775 35

> 775 40

i vi thn 3000mm: 1 ca trn y (hoc trn thn gn vi y) i vi cc thn > 3000mm: 2 ca: 1 ci trn mi y (hoc trn thn gn vi y)

CNG BO/S 585 + 586/Ngy 26-9-2013 73

Ch thch: 1. Cc ca nh hn c th c s dng vi s lng ln hn, vi iu kin: (a) Ca nh nht c ng knh khong trng l 25 mm; (b) Tng cc ng knh t nht bng vi yu cu trong Bng 8; (c) Ca c t ni thch hp kim tra d dng. 2. Cc ca (l khot) ny c th c c bng cch: (a) Tho cc van, ph kin hoc ng; (b) Ct cc ng nhnh gn thn; (c) ng nhnh ring kim tra vi np c hn kn. 3. Nu khng c cc ca, th kim tra c th thc hin bng cch: (a) Ct thn; (b) S dng cc phng php kim tra khng ph hy, xem Ph lc A. 9.4. Cc thit b khng cn ca kim tra Cc thit b khng cn ca kim tra khi: (a) Chng c thit k, ch to v lp t sao cho c th tho d d dng

cho php kim tra bng mt v lm sch tt c cc b mt chu ng sut; hoc (b) Chng c thit k v s dng m s kim tra bng mt khng thc hin

c v p dng mt phng php thay th khc nh gi mc h hng. 9.5. Ca chui ngi i vi cc bnh cha kh khng an ton Cc bnh cha, ti thi im yu cu phi chui vo trong, c kh nng cha kh

khng an ton, nh kh bn hoc thiu xi, phi c lp vi t nht 1 ca chui ngi c kch thc nh nht nh sau:

(a) i vi cc bnh t c nh - khng nh hn 450mm x 400mm (elip) hoc 450mm (trn);

(b) i vi cc bnh c th vn chuyn - khng nh hn 400mm x 300mm (elip) hoc 400mm (trn).

Ch thch: Cc phng tin gip chui vo hoc chui ra khi bnh cn m bo d dng (khng b cn tr). Theo , khi cc kh bn hoc cng vic thc hin trong bnh c th cn n cc ng in, cc vi, hay cc ng thng gi hoc cc ng tng t qua ca kim tra, th nn xem xt c thm mt ca th hai.

9.6. Cc ca khc C th b tr cc ca mt cch khc nh sau:

74 CNG BO/S 585 + 586/Ngy 26-9-2013

(a) Khi hnh dng bnh khng phi l tr, cc ca khng cn p dng, nhng phi c cc ca vi kch c v v tr thch hp cho php tip cn bn trong.

(b) Khi quy nh phi c ca chui ngi nhng hnh dng hay vic s dng ca bnh khng cho php lp c, th cn b tr cc ca kim tra c kch thc 150mm x100mm hoc ng knh 125mm, hoc ln hn. Mt ca phi t trn mi y hoc trn thn gn vi y, hoc ti cc v tr khc cho php s kim tra tt c cc vng c kh nng b hng.

(c) Cc bnh c ng knh trong nh hn hoc bng 315mm, c th s dng ng hay ph kin ti v tr cn c ca kim tra, min l chng c t v tr thch hp, c th d dng d ra lm cc ca kim tra vi s lng v kch thc cn thit.

(d) Cc l rt phi trong cc bnh c thng vo bn trong c th c s dng lm cc ca kim tra, vi iu kin l np c th d dng tho v thay th, ng thi chng c t ni cho php kim tra thch hp.

(e) Cc y hoc np tho c c th c s dng lm cc ca kim tra, min l chng t nht phi c kch c bng vi kch c nh nht cn thit ca loi ca kim tra . Mt y hay np tho c c th c s dng thay cho tt c cc ca kim tra khc khi kch thc v v tr ca ca nh vy cho php thy bn trong t nht l bng vi khi s dng cc ca kim tra khc.

9.7. Kch thc ca cc ca Cc kch thc nn dng ca cc ca kim tra c cho trong Bng 9.

Bng 9. Kch thc ca cc ca kim tra Kch thc tnh bng milimt (mm)

Loi Cc ca trn (ng knh) Cc ca elip tng ng

(trc ln x trc nh)

Chiu su ln nht ca l khot

(xem ch thch 1)

L quan st 30 40 50

- - -

30 40 50

L th tay

75 100 125 150 200

90 x 63 115 x 90

150 x 100 180 x 120 225 x 180

50 50 63 75 100

CNG BO/S 585 + 586/Ngy 26-9-2013 75

Loi Cc ca trn (ng knh) Cc ca elip tng ng

(trc ln x trc nh)

Chiu su ln nht ca l khot

(xem ch thch 1)

L th u Ln nht = 300Nh nht = 290

Ln nht = 320 x 220 Nh nht = 310 x 210

100

L chui ngi 400 450 500

400 x 300 450 x 400

150 245 300

Ch thch: 1. Chiu su ca l khot l khong cch nh nht t b mt ngoi ca l khot

ti b mt trong ca l khot. Cho php ni suy tuyn tnh chiu su ca l khot. Chiu su ln hn c th cho php ch khi chiu su cho trong bng l khng thc hin c

2. Ch c th s dng ca chui ngi elip c 400mm x 300mm hoc hnh trn ng knh 400mm khi cc ca ln hn khng th lm c v trong gii hn di y:

(a) Cc bnh cha hi, nc, kh hoc cc loi khc c m bo rng, ti thi im chui vo bnh bt k, th mi cht cng khng c hi;

(b) i vi cc bnh t c nh, ng knh ca bnh khng ln hn 1530mm; (c) i vi cc bnh nm ngang, ca chui ngi elip trn th trc ln ca elip

nm ngang trc bnh; (d) i vi bnh t ng, ca chui ngi trn thn nm trong khong 700 ti

900mm so vi nn t bnh hoc sn thao tc trn ca bnh, v trc chnh ca elip nm ngang trc bnh.

9.8. Thit k cc ca kim tra Vic thit k cc ca kim tra phi tun theo cc yu cu i vi l khot v

ng nhnh. 9.9. Li vo cc thit b Tr khi khng th thc hin c do thit b cng ngh hoc do cc hon cnh

khc, phi b tr sao cho ch t chn hoc bc thang gn k hoc khng qu 1m n mp di ca chui ngi chui vo thit b.

Cc thanh nm phi c lp t khi c th.

76 CNG BO/S 585 + 586/Ngy 26-9-2013

Chng 3 CC LOI BNH HAI V

1. Yu cu chung Cc bnh hai v, trong c loi mng hai v, phi c thit k theo cc yu

cu a ra cho mi thnh phn c cp n mt s mc trong Quy chun ny, tr nhng im c iu chnh trong mc ny.

Phn v ca bnh c xc nh gm thnh trong v thnh ngoi, cc vnh chn v, v tt c cc chi tit xuyn qua hoc cc b phn khc trong phn v chu ng sut. Cc b phn nh cc ng nhnh, cc phn t chn, cc vng tng cng, vng cng thuc phm vi phn v.

Bnh bn trong phi c thit k chu ton b p sut chnh lch m c th tn ti di bt k iu kin vn hnh no, bao gm c chn khng ngu nhin trong bnh do s ngng t ca cc mi cht hi khi trng hp ny c th xy ra.

Khi bnh bn trong phi hot ng di iu kin chn khng v p sut th thy tnh cho v c tng tng ng th nghim bnh trong t bn ngoi, th phi lu sao cho thn ca phn v c thit k chu c p sut gia tng ny.

nh hng ca cc lc ni ti bn trong v bn ngoi cng vi gin n nhit phi c xem xt. Phi t cc tm v vch ngn va p ti u vo phn v, ni c th xy ra n mn ca bnh v vch ca v do s ngng t ca hi nc hoc cc hi ngng t khc.

2. Cc loi bnh hai v Mc ny p dng vi cc bnh hai v c phn v c bao bc bi thn

hoc y nh minh ha trong Hnh 8 v c phn v mt phn c minh ha trong Hnh 11. Cc phn v, nh ch ra trong Hnh 8 phi khng t qung theo chu vi bnh i vi kiu 1, 2, 4 v 5; v phi trn theo mt ct ngang i vi kiu 3.

Cho php s dng kt hp cc kiu ny trn bnh n min l p ng c cc yu cu ring bit cho mi loi. Cc v dp sng khng cp trong mc ny.

CNG BO/S 585 + 586/Ngy 26-9-2013 77

Hnh 8. Mt s kiu cho php ca bnh hai v 3. Thit k cc thn v v y v Thit k cc thn v v y v phi tun theo cc yu cu trong quy chun ny. 3.1. K hiu ts Chiu dy thc t ca thnh bnh trong, tnh theo milimt; trj Chiu dy cn thit ti thiu ca thnh ngoi ca v, khng tnh phn b sung do

n mn, tnh theo milimt; trc Chiu dy cn thit ti thiu khng tnh phn b sung do n mn ca vnh

chn v nh c xc nh trong mc ny, tnh theo milimt; tc Chiu dy thc t ca phn np v, tnh theo milimt; tj Chiu dy thc t ca thnh v ngoi, tnh theo milimt;

78 CNG BO/S 585 + 586/Ngy 26-9-2013

tn Chiu dy nh mc ca ng ni, tnh theo milimt; r Bn knh gc ca vnh chn v hnh xuyn, tnh theo milimt; Rs Bn knh ngoi ca bnh bn trong, tnh theo milimt; Rj Bn knh trong ca phn v, tnh theo milimt; Rp Bn knh l khot trn v ti ch xuyn qua v, tnh theo milimt; P p sut thit k trong bung v, tnh theo megapascal; Pv Chn khng thit k trong bnh bn trong, tnh theo megapascal; f bn thit k, tnh theo megapascal; j Khong cch gia hai v, tnh theo milimt; Bng bn knh trong ca v tr i bn knh ngoi ca bnh bn trong, tnh theo

milimt; a, b, Cc kch thc mi hn ti thiu cho mi ghp vnh chn v; c, Y, Cho mi ghp cc phn t ca vnh chn v vi bnh bn trong, c o

nh ch ra trong cc hnh minh ha; Z Xem trong Hnh 9, tnh theo milimt; L Chiu di thit k ca phn v nh ch ra trong Hnh 8, tnh theo milimt; di ny c xc nh nh sau: (a) khong cch gia cc ng un y ca bnh bn trong cng vi mt phn

ba su ca mi y trong trng hp khng c cc vng tng cng hoc vnh chn v nm gia cc ng cong y;

(b) khong cch gia tm hai vng tng cng lin k hoc hai vnh chn v, hoc; (c) khong cch t tm ca vng tng cng hoc vnh chn v th nht (gn

y nht) ti ng un y bn trong cng vi mt phn ba chiu su y ca bnh bn trong, tt c c o song song vi trc bnh.

i vi thit k cc phn t vnh chn v hoc vng tng cng, phi s dng gi tr ln hn trong chiu di thit k L ca cc on lin k nhau.

3.2. Vnh chn v Cc vnh chn v phi ph hp vi cc kiu vnh trn Hnh 9 v phi tun

theo cc yu cu sau y, tr khi c tha thun khc gia cc bn c lin quan. (a) Cc kiu vnh chn v trn Hnh 9(a) c s dng trong bnh hai v

Kiu 1, 2 hoc 4 nh ch ra trong Hnh 8. Cc vnh chn v ny c trc t nht phi bng trj v bn knh gc un r phi khng nh hn 3tc. Thit k vnh chn v ny gii hn chiu dy ti a trc l 15mm. Khi kt cu ny c s dng trn bnh hai v Kiu 1, th kch thc mi hn Y phi khng nh hn 0,7tc; v khi c s dng trn bnh hai v Kiu 2 v 4, th kch thc Y phi khng nh hn 0,85tc.

CNG BO/S 585 + 586/Ngy 26-9-2013 79

(b) Cc kiu vnh chn v trn Hnh 9(b-1) v (b-2) c trc t nht phi bng trj. Mi hn ni vnh chn v vi bnh bn trong v ngu hon ton qua chiu dy vnh chn v tc, c th c s dng vi bt k kiu bnh no trong Hnh 8. Tuy nhin, mi hn gc c kch thc chn nh nht l 0,7tc cng c th c s dng ni vnh chn ca bnh hai v kiu 1 trong Hnh 8.

(c) Cc kiu vnh chn v trn Hnh 9(c) ch c s dng trn bnh hai v kiu 1 ch ra trong Hnh 8. Chiu dy vnh chn trc, phi c xc nh theo 3.10 nhng khng c nh hn trj. Gc phi gii hn ti a l 30 .

(d) Cc kiu vnh chn trn Hnh 9(d-1), (d-2), (e-1), v (e-2), ch c s dng trn cc bnh hai v kiu 1 nh ch ra trong Hnh 8 v vi mt hn ch na l trj khng vt qu 15 mm. Chiu dy ti thiu cn thit i vi thanh chn phi l gi tr ln hn trong cc gi tr c xc nh bi cc cng thc sau:

Cc kch thc mi hn gc phi nh sau: trc = 2(trj) (12)

trc = 0.707j

0.5Pf

(13)

Cc kch thc mi hn gc phi nh sau: (i) Y phi khng nh hn gi tr nh nht ca (0,75tc v 0,75ts). (ii) Z phi khng nh hn tj. (e) Thanh chn v mi hn thanh chn vi bnh bn trong ca cc kiu vnh

chn trn Hnh 9 (f-1), (f-2) v (f-3) c th c s dng trn bt k kiu bnh hai v no trong Hnh 8. i vi cc kiu khc ca bnh hai v, chiu dy ti thiu cn thit ca thanh chn phi c xc nh bi cng thc sau:

trc = 1.414

0.5sPR j

f (14)

Chiu rng khong trng ca v phi khng vt qu gi tr c xc nh bi cng thc sau:

j = ( )2s s jj

2ft- 0.5 t + t

PR (15)

Kch thc mi hn kt ni thanh chn vi bnh trong nh sau: (i) Y phi khng nh hn gi tr nh nht ca (1,5tc v 1,5ts) v phi c o nh

l tng ca kch thc a v b nh ch ra trong cc minh ha tng ng trn Hnh 9. (ii) Z cao ti thiu chn mi hn gc cn thit khi c s dng kt hp

mi hn c rnh hoc mi hn gc khc duy tr kch thc Y ti thiu cn thit. (f) Mi hn ni v vi thanh chn trn Hnh 9(g-1), (g-2) v (g-3) c th

c s dng trn bt k kiu bnh hai v no trong Hnh 8. Cc mi hn kt ni nh ch ra trong Hnh 9(g-4) c th c s dng trn bt k kiu bnh hai v no trong Hnh 8 khi trj khng vt qu 15mm. Cc mi hn kt ni nh ch ra trong

80 CNG BO/S 585 + 586/Ngy 26-9-2013 Hnh 9(g-5) v (g-6) c th c s dng trn bnh hai v kiu 1 trong Hnh 8 khi tj khng vt qu 15mm.

(g) Mi mi hn hng tm trong phn t vnh chn v phi l mi hn gio mp ngu qua ton b chiu dy ca phn t v phi mi phng khi cc mi hn thc hin xong.

(j) Cc mi ghp bt k kiu v c ni ghp c th c thit k theo cc yu cu ca cc v kiu 1 nh trong Hnh 8 min l ton b v c ni ghp bng bu lng b c cho lc p sut ln y.

Hnh 9. Mt s kiu vnh chn v c chp nhn

CNG BO/S 585 + 586/Ngy 26-9-2013 81

3.3. Chi tit xuyn qua cc v Cc yu cu sau c p dng i vi l qua cc v: (a) Thit k cc l xuyn qua khong trng gia hai v phi tun theo cc yu

cu ca quy chun ny. (b) Gia cng l trn v khng yu cu i vi cc chi tit xuyn qua nh ch

ra trong Hnh 10 do l ny c tng cng bi tc dng ca ng nhnh hoc c ng ca phn t chn.

(c) Chiu dy ti thiu ca phn t chn xuyn qua v ch tnh n ti trng p sut.

(d) Cc thit k phn t chn xuyn qua v bnh nh ch ra trong Hnh 10 s tun theo cc yu cu sau y:

(i) ng nhnh c th c s dng nh phn t chn nh ch ra trong Hnh 10(a), khi v c hn ti ng ni.

(ii) Chiu dy ti thiu cn thit trc, i vi cc thit k trong Hnh 10(b) v (d) phi c tnh ton nh thn chu p sut ngoi.

(iii) Chiu dy ti thiu cn thit trc, i vi thit k Hnh 10(c) phi bng trj. (iv) i vi cc thit k Hnh 10(e-1) v (e-2), chiu dy cn thit ca phn t chn

gn vo bnh bn trong trc1, phi c tnh nh thn chu p sut ngoi theo 3.9. Chiu dy cn thit ca phn t linh hot trc2 phi c xc nh bi mt trong cc cng thc di y:

Khi khng c on hnh ng gia v v xuyn:

trc2 = Pr

(f - 0.5P) (16)

Khi c cc on hnh ng gia v v xuyn:

trc2 = pPR

(f - 0.5P) (17)

Trong : H s bn mi hn t Bng 3 i vi mi hn theo chu vi trong xuyn trong

cng thc c s dng r, hoc i vi bt k mi hn no trn phn t chn l khot trong cng thc c s dng Rp (bn knh ca chi tit xuyn qua).

(v) Chiu dy ti thiu trc, i vi thit k trong Hnh 10(f) phi c tnh nh thn c bn knh Rp, chu p sut ngoi.

(vi) Cc thit k trong Hnh 10(b), (c), (d) v (e) a ra tng linh hot khi s dng v c thit k trn c s tng t i vi cc mi ni b gin n.

82 CNG BO/S 585 + 586/Ngy 26-9-2013

Hnh 10. Mt s kiu chi tit xuyn qua c chp nhn (vii) Tt c cc mi hn hng tm trong cc mng chn lm kn l khot phi

l cc mi hn gip mp ngu hon ton qua ton b chiu dy ca phn t. (viii) Cc khoang ca phn t chn phi c hnh trn, elp hoc hnh y cong

nu c th. Cc khoang phn t chn hnh ch nht c php s dng, min l cc gc c un trn vi bn knh ph hp.

CNG BO/S 585 + 586/Ngy 26-9-2013 83

3.4. Cc v mt phn (khng bao gm cc mng) Cc v mt phn l cc v bao quanh khng ht chu vi ca bnh. Mt s kiu

v ny c ch ra trong Hnh 11.

Hnh 11. Mt s kiu v mt phn

(Xem tip Cng bo s 587 + 588)

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