A21 is the spring Weiqi safety valve thread.
Type A21H is suitable for the work temperature are less than 200 of the air, ammonia, oil gas and other media equipment and pipeline.
Type A21W is suitable for equipment and Road gas or liquid for working temperature is not higher than 200 DEG with corrosive on.
Type A21F is suitable for the work temperature are less than 200 of the liquefied gas, gas pipeline and other equipment. As overpressure protection device
Body structure: closed; the valve opening height: Weiqi; structure: spring type; main material: stainless steel; suitable temperature: 200; pressure range: 1.6-10.0Mpa; medium: air, steam, water, nitrogen and hydrogen mixed gas; nominal diameter: 15-80 (mm); connection form: thread Product Name:; micro and safety valve with a wrench spring; applicable scope: national defense, scientific research, aerospace, electronics, machinery, metallurgy, petroleum, chemical, energy, environmental protection, bio medicine, refrigeration, food etc.