Chemical valves

Chemical valves are an important accessory to control the flow of media on chemical pipelines.

Function

1. or communicate with the flow of fluid in the tube;

2, regulating role - to regulate the flow rate in the tube, flow rate;

3. throttling effect - to make the fluid through the valve after a large pressure drop;

4. other roles --a. Automatically open and close b. Maintain a certain pressure c. Block steam drainage.

Types

1.1 By application: cutoff valves, regulating valves, diverter valves, check valves, safety valves;

1.2 By application: cutoff valves, regulating valves, diverter valves, check valves, safety valves;

2. By force: other-acting valves, automatic valves.

Primary

PN Nominal pressure (the maximum pressure through which fluid is allowed to pass);

DN nominal diameter;

TN temperature range (the temperature range over which the fluid is allowed to pass).

Pre-use inspection

Inspection items include:

1. whether there are defects such as sand holes and cracks on the inner and outer surfaces of the valve body;

2. whether the valve seat is firmly bonded to the valve body, whether the valve spool fits the valve seat, and whether there are defects on the sealing surface;

3, whether the stem and spool connection is flexible and reliable, whether the stem is bent, whether the thread is damaged and corroded;

4, whether the packing and gasket are

5, whether the valve is flexible to open, etc.

Common problems

1. Leakage of flanges and threads at the connection with the pipeline;

1. font-size: 15px;line-height: 30px;"> 2, packing culm leakage, waist gasket leakage and valve stem opening;

3, the spool and the valve seat is not closed tightly to form internal leakage.

Selection principles

The chemical industry generally selects valves with straight flow paths because of the lower flow resistance, and Usually choose to cut off and open the media with the valve, this type of valve is easy to adjust the flow of valves used as control flow, ball valves and plug valves are suitable for directional diversion with the sliding of the closing member along the sealing surface with the wiping effect of the valve, such words are suitable for the media with suspended particles. Usually we see the use of more chemical valves are globe valves, ball valves, gate valves, safety valves, check valves, plug valves and so on. Chemical valve media mainstream with chemical substances, containing acid and alkali corrosive media mostly.

• Beijing Xinmuyuan Technology Co., Ltd
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