we can supply relief valve Here are brief introduction of our company: THE SNPN MECHANICAL FACTORY is specializing in manufactuary of pneumatic，including Safety Valve、Non-return valve、ball valve、Series of Pressure Regulating Valve and so on. Our company located in YUHUAN county,Zhejiang province as ＂the capital of valve in china＂We established in 1992 ,we have more than 300 staff and the total value more than 50 million RMB this year. The kind of valve is a safety valve which directly loaded by spring and sealed by rubber, It will be locked by locknut after adjust the pressure nut of container. And it has a yellow (red or black) dustproof plastic cap on outside. It is a indispensa