Zhejiang TianEn Pressure Vessel Co.,Ltd is a ProfessionalManufacturerof Seamless Steel gas cylinders, CNG-1 cylinder in Zhejiang, China . Zhejiang Tianen CNG cylinders : The specification of our CNG cylinder of Type-1 as following :Production standard : ISO11439 ,GB17258.Working Pressure :20Mpa ,Testing Pressure :30MPa ,33.4Mpa.Water Capacity :20L, 25.5L, 28L, 34L,50L ,57L ,65L, 70L ,75L, 80L,85L,90L ,95L,100L ,110L,113L,120L,130L,150L.Out Diameter :232MM, 325MM, 356MM ,279MM,406MM .Wall thickness :5.5MM ,6.4MM,7.6MM,8.2MM, 8.8MM,9.0MM.Material :34CrMo4 ,30CrMo.Other speciifcation also available for customers requirement . Welcome to inquiry us . We will reply you immediatelly .