Steel welded seamless pipe fittings GB / T 12459-2005 " […]
Steel welded seamless pipe fittings GB / T 12459-2005
"Steel welded pipe fittings" GB / T 13401-2005
"DL / T 695-1999" power plant steel pipe fittings
SH 3408 steel welded seamless pipe fittings
SH 3409 is made of welded steel pipe
SH 3410 Forged Steel Socket Welding Accessories
HGJ514-87 carbon steel, low alloy steel seamless pipe fittings