SYP cng cylinder is strict product in according to ISO11439:2000 and DOT 3AA(American area use) . each cylinder will be 100% achieve hydraulic pressure test before we ship to our customer . All the cylinder is Pass finish the type test and choose the 34CrMo4 seamless steel tube for Type 1 and Type 2 CNG cylinder Till now SYP can offer to our customer the full serice CNG cylinder product as following Type 1 steel CNG cylinder Type 2 Glass fiber hoop wrapped Steel CNG cylinder ISO11439:2000 standard Type 3 Carbon fiber full wrapped aluminum CNG cylinder Cylinder size and volume we offerType 1 279mm seriese from 20L , 30L. 35L. 40L. 55L. 60L. 70L. 80L 325mm series from 40L. 50L. 60L, 70L. 80L. 90L. 100L.110L. 120L 356mm series from 60L , 70L, 80L, 90L, 100L, 110L, 120L 130L. 140L 406mm series from 60L , 70L, 80L, 90L, 100L, 110L, 120L 130L. 140L