General technical description for slow closing check valve drainage:
The main function of the slow-closing check valve is to prevent the backflow of the medium in the pipeline, also known as the check valve. The horizontal installation method is generally adopted. Here is a general technical description of the slow-closing check valve for drainage. There are mainly fifteen points:
1. The structural length and dimension of the flanged slow-closing check valve should be in accordance with the provisions of GB/T12221 or according to the agreement of the user. When the butterfly check valve is opened, the extension length of the butterfly plate should 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 smaller wall thickness of the valve body should meet the requirements of GB/T12236, GB/T12238 or GB/T13932 standards.
4.1 The material of main parts such as valve body, valve cover, valve disc (disc) and valve shaft of the slow-closing check valve shall be in accordance with the provisions of GB/T12236, GB/T12238 or GB/T13932.
4.2 The material of the damping piston cylinder of the slow-closing device should meet the requirements of the system pressure, the surface of the piston and piston rod should be plated with hard chrome, and the sealing ring of the piston and piston rod should be made of oil-resistant materials such as stacking rubber.
4.3 The anti-corrosion coatings and rubber seals used in the valve body cavity of the slow-closing check valve for water supply and other metal parts in contact with water should be non-toxic and tasteless.
5. The closing process of the slow-closing check valve should be divided into two stages: quick-closing and slow-closing, and the slow-closing time should 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 should be adjustable throughout the entire process.
7. The check valve disc (disc) of the slow-closing check valve should be opened and closed flexibly without jamming.
8. The damping piston in the slow closing device must be sensitive, and can automatically and quickly extend to the predetermined working position when the reverse valve disc (disc) is opened, and can start when the reverse valve disc (disc) is closed to the slow closing position. Effective soothing action. The capacity of the damping piston cylinder in the slow closing device should be matched with the regulating valve used, so as to avoid excessive force of the damping piston cylinder and pipeline, and achieve the purpose of adjusting and eliminating hammer.
9 The slow-closing device of the external damping slow-closing check valve and the hydraulic-controlled butterfly check valve shall be equipped with a mechanism for monitoring the liquid level of the damping medium.
10. The self-damping slow-closing return valve does not allow raw water, sewage, etc. with solid particles to directly enter the slow-closing device, so as not to block or damage the seal.
11 Hydraulic control butterfly check valve and butterfly slow closing check valve shall be provided with an indicating mechanism that correctly displays the opening position of the butterfly plate.
12 Hydraulic control butterfly check valve should be set with heavy hammer or accumulator as an additional force source, in case the valve is automatically closed when power is cut off.
13 The connection, transmission and support of the slow-closing device should have sufficient strength and rigidity.
14 Hydraulic device: Standard hydraulic parts and electrical parts should be products with reliable quality, good performance and long service life, and should be tested according to the regulations of their respective relevant standards, and can only be used after passing the test. After the hydraulic device is assembled, the performance test and adjustment of various parameters should be carried out to make it meet the design requirements of “slow closing” of the valve.
15. The external paint layer and color of the slow-closing check valve should be uniform, the appearance should be smooth and smooth, and there should be no defects such as scars, sagging, blisters and obvious cracks.
The above fifteen points are the general technical instructions on the drainage of slow-closing check valves that I shared with you today. If you find it helpful, please forward it~