seamless tube and pipe for lowand medium pressure boiler Grade:20 OD:25---76mm WT:1.5--4.0mm Seamless tube and pipe for ... lowand medium pressure boiler-----American Petroleum Institute:Certificate of Authority ... , DZ40, DZ50, N80, J55, GCr15, GCr15SiMn, GCr9, GCr9SiMn seamless tube and pipe for low and medium pressure boiler