Valve, valve core, valve cage, the ring material should be rigid steel or alloy steel, or for processing, such as nitriding or surface coating (for example, Levin-plated Adams too).

• 阀体、阀芯、阀笼、胶木手轮、座环的材质应采用硬质钢或合金钢，或者进行渗氮等处理或加表面涂层(譬如镀斯太莱)。