The general technical conditions of drainage cast basalt valve are introduced by the manufacturer of cast basalt plate

Cast basalt valve is introduced by the manufacturer of cast basalt plate. Now the relevant contents of the standard are introduced as follows: cast basalt valve. The standard is applicable to nominal pressure PN4.0MPa and nominal diameter DN? 4000mm, the working temperature is not greater than 80 ° C, and the working medium is drinking water, raw water, industrial circulating water, seawater, sewage and other non corrosive media. The technical requirements in the standard are as follows:

1. The structural length and dimension of flange connected slow closing check valve shall be in accordance with the provisions of GB / t12221 or as agreed by the user. When the butterfly check valve is opened, the extension length of the butterfly plate shall not affect the use.

2 flange connection size and sealing surface type shall comply with the provisions of GB / t17241.6, GB / t17241.7 or GB / t9112.

3 the minimum wall thickness of valve body shall comply with the provisions of GB / t12236, GB / t12238 or GB / T 13932 standards.

4 materials

4.1 the materials of main parts such as valve body, bonnet, disc (butterfly plate) and valve shaft of slow closing check valve shall comply with the provisions of GB / t12236, GB / t12238 or GB / t13932.

4.2 the material of damping piston cylinder of slow closing device shall meet the requirements of system pressure, the surface of piston and piston rod shall be plated with hard chromium, and the sealing ring of piston and piston rod shall be made of oil resistant materials such as laminated rubber.

4.3 the anti-corrosion coating and rubber seal used for the inner cavity of slow closing check valve body for water supply and other metal parts in contact with water shall be non-toxic and tasteless.

5 the closing process of slow closing check valve shall be divided into two stages: quick closing and slow closing, and its slow closing time shall be adjustable.

6 the slow closing opening of the check valve disc of the slow closing check valve, that is, the extension length of the slow closing piston, shall be adjustable in the whole process.