National standard, American standard, British standard, and various non-standard high-pressure stamping "Steel plate welded fittings" GB/T13401-2005 specification for reducing pipe standards
The quality of the reducing pipe should comply with the current national standard "Steel Welded Seamless Pipe Fittings" GB/T12459-2005
Standard GD0506~0507 of the Ministry of Electric Power
Groove clamp type reducer
Groove clamp type reducer
National standard (GB/T9112-2000)
Mechanical Department Standards (JB81-59, JB/T74-94)
Petrochemical Department Standard (SH3406-96)
Ministry of Chemical Industry Standards (HG5010-58, HG20592-97)