... ,B,X42,X52,X56,X60,X65,X70,X80 2.standard:API 5L seamless linepipe The line pipe is used for gas, water ... is plain or thread. And the connection are welding ends, coupling, bell and spigot .The grades are A,B,X42,X52 ... ,X42,X52,X56,X60,X65,X70,X80TypeSeamless, weldingEndPlain, bevelConnectionWelding ends, coupling, bell and spigotWorkmanshipERW,SSAW,LSAW