... J55,K55,N80,L80,P110.usage:Tubing is used in extracting gas. casing pipe serves as wall of well ... API gas tube.API SPEC 5CT J55\K55\N80\ ... transportation of gas,water,oill in oil&gas industry.API SPEC 5CT.Tubing is used in extracting petroleum & natural gas. casing ... boiler,water&petroleum.ASTM A53 It is used for conveying water,petrolem,gas and other common fluids.ASTM A179 ...