译文：
一、常用材料 针型阀门通常由阀体、阀盖、阀瓣（闸板）、阀座、阀杆、热片、填料及驱动装置（手轮、齿轮箱或气动、电动装置等）组成。 针型阀门里的阀体、阀盖的材料为壳体材料（也称主体材料），闸板（阀瓣）、球体、阀座、阀杆、密封座常常称为内件，此外还有紧固件、密封件等。 按壳体/主体材料分类，针型阀门可分为： 1.金属材料针型阀门：如碳钢阀门、合金钢阀门、不锈钢阀门、铸铁阀门、钛合金阀门、蒙乃尔阀门、铜合金阀门、铝合金阀门、铅合金阀门等。 2.金属阀体衬里针型阀门：如衬胶阀门、衬氟阀门、衬铅阀门、衬塑阀门、衬搪瓷阀门。 3.非金属材料针型阀门：如陶瓷阀门、玻璃阀门、塑料阀门。 二、材料的选用原则 一般情况下，针型阀门材料应根据其参数及材料的性能按本标准选用，并应符合有关产品标准的规定。也可选用性能不低于本标准规定的或供购双方合同商定的其他材料。 而特殊情况下针型阀门的技术要求如下： 1.灰铸铁制针型阀门 用于公称压力pN≤1.0MPa，温度为–10~200℃的水、蒸气、空气、煤气及油类等介质的灰铸铁制阀门。 2.可锻铸铁制针型阀门 用于公称压力pN≤2.5MPa，温度为–30~300℃的水、蒸气、空气及油类等介质的可锻铸铁制阀门。 3.球墨铸铁制针型阀门 用于公称压力pN≤4.0MPa，温度为–30~350℃的水、蒸气、空气及油类等介质的球墨铸铁制阀门。 4.铜合金制针型阀门 用于公称压力pN≤2.5MPa的水、海水、氧气、空气、油类等介质，以及温度为–40~250℃的蒸气介质的铜合金制阀门。 5.碳素钢制针型阀门 用于公称压力pN≤32.0MPa，温度为–30~450℃的水、蒸气、空气、氢气、氨、氮及石油产品等介质的碳素钢制阀门。 6.高温钢制针型阀门 用于公称压力pN≤16.0MPa，温度小于或等于550℃的蒸气及石油产品等介质的高温钢制阀门。 7.低温钢制针型阀门 用于公称压力pN≤6.4MPa，温度高于或等于–196℃的乙烯、丙烯、液态天然气及液氮等介质的低温钢制阀门。 8.不锈耐酸钢制针型阀门 用于公称压力pN≤6.4MPa，温度低于或等于200℃的硝酸、醋酸等介质的不锈耐酸钢制阀门。

“ Needle valve commonly used materials and materials selection of the principles of ”是由提供的国际阀门新闻，译文仅供参考。另外，中国针型阀网还提供相关产品搜索：、、、、等。

原文：
A commonly used material Needle valve is usually the valve body, valve cover, valve valve (gate), valve seat, stem, hot films, packing and drive unit (hand wheel, gear box or pneumatic, electric devices, etc.). Needle valve inside the valve body, valve cover material for the shell material (also known as the main material), gate (valve flap), ball, valve seat, stem, sealing seat is often referred to as cases, in addition to fasteners, seals and so on. By shell / main material categories, needle-type valves can be divided into: 1. Metallic Materials needle valve: If carbon steel valves, alloy steel valves, stainless steel valves, cast iron valves, titanium valves, Monel valves, copper alloy valves, aluminum valves, lead alloy valves and so on. 2. Metal body lined with needle-type valve: If the rubber lined valves, lined valves, lead-lined valves, lined with plastic valves, valves lining enamel. 3. Non-metallic materials, needle valves: valve, such as ceramics, glass valve, plastic valve. Second, the principle of material selection Under normal circumstances, needle valve materials shall be in accordance with its parameters and properties of the materials selected in accordance with this standard and shall comply with the relevant product standard requirements. Can also use the performance of not less than specified in this standard or for a contract the two sides agreed to purchase other materials. The exceptional circumstances, the technical requirements of needle valve are as follows: 1. Gray cast iron needle valve For the nominal pressure pN ≤ 1.0MPa, a temperature of -10 ~ 200 ℃ of water, steam, air, gas and oil and other media, gray cast-iron valves. 2. Malleable iron needle valve For the nominal pressure pN ≤ 2.5MPa, a temperature of -30 ~ 300 ℃ of water, steam, air and oil and other media malleable iron valves. 3. Ductile iron needle valve For the nominal pressure pN ≤ 4.0MPa, a temperature of -30 ~ 350 ℃ of water, steam, air and oil and other media, ductile iron valve system. 4. Copper alloy needle valve PN pN ≤ 2.5MPa for water, sea water, oxygen, air, oils and other media, as well as the temperature of -40 ~ 250 ℃ steam medium copper alloy valves. 5. Carbon steel needle valve For the nominal pressure pN ≤ 32.0MPa, a temperature of -30 ~ 450 ℃ of water, steam, air, hydrogen, ammonia, nitrogen and petroleum products such as medium carbon steel valves. 6. High temperature steel needle valve For the nominal pressure pN ≤ 16.0MPa, the temperature is less than or equal to 550 ℃ steam and petroleum products such as media, high-temperature steel valves. 7. Cryogenic steel needle valve For the nominal pressure pN ≤ 6.4MPa, the temperature is higher than or equal to -196 ℃ ethylene, propylene, liquefied natural gas and liquid nitrogen temperature steel valves and other media. 8. Stainless acid-proof steel needle valve For the nominal pressure pN ≤ 6.4MPa, temperature is less than or equal to 200 ℃ of nitric acid, acetic acid and other media, stainless steel valves.