CNG Cylinders

CNG Cylinders Type I: Material & ProductionCNG Cylinders Type I: Material & Production

National Metal and Materials Technology Center (MTEC)National Metal and Materials Technology Center (MTEC)National Science and Technology Development Agency (NSTDA)National Science and Technology Development Agency (NSTDA)

““การผลิตการผลิต การใชการใช และการกํากับดูแลถังและการกํากับดูแลถัง CNG CNG ใหปลอดภัยใหปลอดภัย””Boiler & Pressure Vessel 2009Boiler & Pressure Vessel 2009

2727 กุมภาพันธกุมภาพันธ 25522552ศูนยการประชุมศูนยการประชุมอิมแพคอิมแพคเมืองทองธานีเมืองทองธานี

Tank & Safety Valve

Pressure Regulator

Pressure Gauge Refilling

Valve

SwitchECU

Electronic SparkAdvance Control

Gas Filter

Injector Rail

OverviewOverview

MaterialMaterial

• Primary alloying element: C, Si, Mn• Secondary alloying element: Cr, Mo, Ni• Trace element: P, S

0.05

0.10

0.15

Gas

cap

acit

y-w

eigh

t ra

tio

(m3

/kg)

0.20

1900 1920 1940 1960 1980 2000

(BS 399/400)(BS 399/400)Carbon steelCarbon steel

(BS 1045/1288)(BS 1045/1288)Carbon Carbon

manganese manganese steelsteel

Chromium molybdenum Chromium molybdenum steelsteel

(BS 5045)(BS 5045)

(HOS)(HOS)

YearYear

High strength steels for CNG cylindersHigh strength steels for CNG cylinders

0.060.080.170.421.150.660.410.22From MTEC Tank

0.035 max.

0.035 max.NA

0.15-0.3

0.9-1.20.6-0.9

0.4 max.

0.3-0.37

34CrMo 4 (DIN 17200)

0.025 max.

0.025 max.

0.25 max.

0.15-0.25

0.8-1.10.4-0.6

0.15-0.35

0.28-0.334130(AISI)

0.040 max.

0.035 max.

1.65-2.00.2-0.3

0.4-0.6

0.45-0.65

0.15-0.35

0.17-0.224320(AISI)

0.040 max.

0.035 max.

1.65-2.00.2-0.3

0.7-0.90.6-0.8

0.15-0.35

0.38-0.434340 (AISI)

0.05 max.

0.05 max.2.3-2.80.4-0.7

0.5-0.80.5-0.7

0.1-0.35

0.27-0.35NCM (BS 5045)

0.05 max.

0.05 max.

0.5 max.

0.15-0.25

0.8-1.20.4-0.9

0.1-0.35

0.37 max.CM (BS 5045)

% S%P%Ni%Mo%Cr%Mn%Si%CSteel Grade

MaterialMaterial

81703560IE (J) at -50˚C

18171414Elongation (%)

1046.61118.79901100UTS (N/mm2)

957.61004.3890990YS (N/mm2)

4340 - II4340 - IFaberISO 9809Mechanical Properties

43404340--I: Tempering @ 590I: Tempering @ 590˚̊C, 4340C, 4340––II: Tempering @ 620II: Tempering @ 620˚̊CC

High strength steels for CNG cylindersHigh strength steels for CNG cylindersMaterialMaterial

MicrostructureMicrostructureMaterialMaterial

Seamless pipeSeamless pipeMaterialMaterial

•• AdvantagesAdvantages-- Thin wall (Thickness to OD ratioThin wall (Thickness to OD ratio

= 0.2%)= 0.2%)-- Dimension accuracy Dimension accuracy

(prevent eccentricity and thickness(prevent eccentricity and thicknessdeviation)deviation)

-- Improved inner surfaceImproved inner surface(prevent roll(prevent roll--in scale)in scale)

•• Standard: Standard: JIS G 3429JIS G 3429 (Seamless Steel Tubes for High Pressure Gas Cylinder)(Seamless Steel Tubes for High Pressure Gas Cylinder)

•• Grade:Grade:STH 22 (ChromeSTH 22 (Chrome--molybdenum steel tube)molybdenum steel tube)

•• Chemical composition:Chemical composition:C = 0.33C = 0.33--0.38%, Si = 0.150.38%, Si = 0.15--0.35%, 0.35%, MnMn = 0.40= 0.40--0.90%, P = 0.030% max.0.90%, P = 0.030% max.S = 0.030%(max), Ni = 0.25%(max), Cr = 0.80S = 0.030%(max), Ni = 0.25%(max), Cr = 0.80--1.20%, Mo = 0.151.20%, Mo = 0.15--0.30%0.30%

Type 2Type 2 Type 3Type 3 Type 4Type 4

Type 1Type 1

CNG Type Weight Cost

Type-1: Metal Cylinders 100% 40%

Type-2: Metal liner - Hoop wrapped cylinders 55-65% 80-95%

Type-3: Metal liner - Fully wrapped cylinders 25-45% 90-100%

Type-4: All Composite cylinders 30% 90%

ProductionProduction

1. Steel : billet2. Steel : plate3. Steel : tube4. HS steel : plate5. HS aluminum : billet6. Aluminum : tube/E-glass hoop7. Steel : plate/E-glass hoop8. Steel : billet/E-glass hoop9. Aluminum : tube/E-glass full10.Aluminum : plate/E-glass full11.Aluminum : plate/S-glass full12.Aluminum : thin/carbon full13.Plastic/carbon full14.Plastic/E-glass full15.Plastic/hybrid full

11

8

2

15

4

0.00

0.10

0.20

0.30

$0.00 $0.50 $1.00 $1.50

Total Cost ($/scf)

Spe

cific

Wei

ght (

lb/s

cf)

1

7

13

6

3

10

12

914

5

NGV Cylinder Weight vs. Cost

Ref. “Compressed Natural Gas Storage Optimization for Natural Gas Vehicles” Final Report, Dec., 1996, Prepared by IGT and Powertech Labs for GRI


CNG Type : 1 CNG Type : 1 –– steel cylindersteel cylinder

Material : BS5045 Steel / AISI4340Material : BS5045 Steel / AISI4340

Cylinder Volume : 70 LittersCylinder Volume : 70 Litters

Weight : 70Weight : 70--80 kg80 kg

Working pressure : 200 barsWorking pressure : 200 bars

Mileage : about 200 km/refillMileage : about 200 km/refill

Periodic Test : every 5 yearsPeriodic Test : every 5 years

Service Life : 20 yearsService Life : 20 years

:most commonly used in Thailand


CNG cylinder typeCNG cylinder type--II

Heating

External – Internal shot blasting

Cupping –Hot Extrusion

Wall thickness reduction

Shell Inspection

Quenching & Temping

Hot spinning

shot blastingNeck Machining

(www. faber-italy. com)

Production Production –– CNG Cylinder Type CNG Cylinder Type -- II

Detailed Detailed manumanu. process (steel billet) . process (steel billet)

Hardness Test Shell Inspection Neck Threading

Ultrasonic Inspection MarkingVolumetric Expansion

Hydro test

Surface Coating Final Operation Shell Inspection

(www. faber-italy. com)


Detailed Detailed manumanu. process (steel billet) . process (steel billet)

Cold Deep Drawing

Cold Deep Drawing

Annealing Flow Forming Hot Neck Spinning

•• Main machines required Main machines required -- Drawing hydraulic press: tonnage 1500 ton upDrawing hydraulic press: tonnage 1500 ton up-- Flow forming machineFlow forming machine-- Hot spinning machine Hot spinning machine


Main Main manumanu. process (steel plate) . process (steel plate)

Base Spinning Base Shaping – Internal Dressing

Flowing Forming Hot Neck Spinning

(www faber italy com

•• Main Machines Required Main Machines Required -- Flow Forming MachineFlow Forming Machine-- Hot Spinning MachineHot Spinning Machine


Main Main manumanu. process (steel tube) . process (steel tube)

1.1. Material tests Material tests

2.2. Hydrostatic Pressure Burst testHydrostatic Pressure Burst test

3.3. Pressure Cycling Test Pressure Cycling Test

4.4. Leak Before Break Test Leak Before Break Test

5.5. Bonfire TestBonfire Test

6.6. Gunfire TestGunfire Test

Bonfire testBonfire test

Gunfire test


Prototype testing (ISO 11439) Prototype testing (ISO 11439)

Gunfire testGunfire test

Leak before break testLeak before break test

Thank You for Thank You for Your Attention!!!Your Attention!!!

Documents

CNG Cylinders