Needle valve technical requirements:
Under normal circumstances, the needle valve material should be selected according to this standard according to its parameters and material properties, and should comply with the relevant product standards. It can also use other materials whose performance is not lower than that specified in this standard or agreed upon by the buyer and the seller. The technical requirements of the needle valve under special circumstances are as follows:
1, gray cast iron needle valve:
For gray pressure cast iron valves with a nominal pressure of pN ≤ 1.0 MPa and a temperature of -10 to 200°C in water, steam, air, gas, and oils.
2, malleable cast iron needle valve:
For the nominal pressure pN ≤ 2.5MPa, temperature -30 ~ 300 °C of water, steam, air and oil and other media malleable cast iron valve.
3, ductile iron needle valve:
Used for nominal pressure pN ≤ 4.0MPa, temperature -30 ~ 350 °C water, steam, air and oil and other medium ductile iron valve.
4, copper alloy needle valve:
It is used for valves made of copper alloys, such as water, seawater, oxygen, air, and oils with a nominal pressure of pN ≤ 2.5MPa, and steam media with a temperature of -40 to 250°C.
5, carbon steel needle valve:
For carbon steel valves with a nominal pressure of pN≤32.0MPa and temperatures of -30 to 450°C in water, steam, air, hydrogen, ammonia, nitrogen and petroleum products. Valve inlet pump
6, high temperature steel needle valve:
High-temperature steel valves for mediums such as steam and petroleum products with nominal pressures pN ≤ 16.0 MPa and temperatures less than or equal to 550°C.
7, low-temperature steel needle valve:
Low temperature steel valves for mediums such as ethylene, propylene, liquid natural gas and liquid nitrogen with nominal pressures pN ≤ 6.4 MPa and temperatures above or equal to -196 °C.
8, stainless acid resistant steel needle valve:
It is used for valves made of stainless acid-resistant steel with a nominal pressure of pN ≤ 6.4MPa, a temperature of less than or equal to 200°C, **, and acetic acid.