Stems shall be of dezincification-resistant silicon bronze ASTM B 371 or low-zinc alloy B 99, non-asbestos packing and malleable or ductile iron handwheel.

阀杆材质是符合美国材料试验协会ASTMB 371标准抗失锌现象的硅青铜，或B 99低锌合金，不含石棉的填料，和可锻或球墨铸铁手轮。