Normally, Needle Valve materials should be based on the parameters and the properties of materials according to the standard, and shall conform to the relevant provisions of the standard products. Also can choose performance not less than the standard for the purchase contract or agreed by the parties and other materials.
And special circumstances needle valve technical requirements are as follows:
1 needle valve of grey cast iron
For nominal pressure, temperature than 1.0 MPa pN -- 10 ~ 200