api 5L X52,ISO 3183 L320 seamless steel pipe, for gas and oil lines

boiler tube
ASME SA-192M,Grade SA-192 boiler steel tube, OD 22 inch SCH40
November 17, 2016
astm a53
ASTM A53, ERW steel pipes, Grade B, SCH40.OD219.1mm
November 30, 2016