主要零部件材料 Materials for main parts                

GA41H、A51H型安全阀除杠杆（材料为碳钢），重锤（材料为铸铁），其余材料均和A41H-16C型弹簧式安全阀相同。

GA41H, A51H type safety valve, except the lever ( material is  carbon steel), hammer (material is cast iron),  the materials of other parts is the same as A41H-16C spring load type safety valve.