“Quality is never an accident; it is always the result of high intention, sincere effort, intelligent direction and skillful execution; it represents the wise choice of many alternatives.
TYPICAL QUALITY ASSURANCE PLAN FOR CNG AUTOMOTIVE CYLINDERS.
Sr. No.
Description Of Work.
Characteristic
Acceptance Limits.
Method of Test.
Quantum of Check.
Format of Records.
1
Design
Thickness calculation
2
Raw material Check
Chemical Composition
As given in Drawing
Chemical Analysis
Mill TC
3
Roundness,Mean dia,,Straightness & Verticality
Measuring
Visually & Measurements
5%
Recorded
4
Heat Treatment
Quenching tempering
Time - Temp Chart
100%
Temp chart/numbering Recorded
5
Hardness Test.
Hardness
Brinell
6
Neck thread.
Threads
Gauges
7
Volumetric Capacity.
Water capacity
+ 5% - 0 %
Deferential Weighing
8
Volumetric expansion test
Pressure Testing
At test pressure for 30 sec.
Hydraulicaly Pressurised
9
Pneumatic Leakage Test.
Leakage Testing
At working pressure for 60 Sec
Air Pressure
10
Visual Inspection
Defects
No Injurious defects
Visual
11
Pressure cycling test
Fatigue Test
15000 Cycles At 260 BAR
Pressurising & Depressurising
1 Cyl./Batch
12
Hydraulic pressure Burst Test.
Burst Pressure
450 BAR
Pressuring for Rupture
Cyl of Press. Cyc. Test
13
Bonfire test
Behavior at temperature
Vent through pressure Relief Device
Heating of gas filled cylinder.
14
Leak before break test
Pressure Cycling
45000 Cycles at 300 Bar
3 Cyl./Batch
15 A
Physical Tests
Mechanical properties
Tensile, Impact , etc.
B
Thickness
THICKNES GAUGE
C
Base check
THICKNES GAUGE & VISUAL
16
Exterior Coating.
D.F.T.
Spray
2%
17
Markings
Data verification
18
Ultra Sonic Flaw Detection
Checking Internal Defects
Defect size <5 % of W T
Contact /ss Immersion
