Chemical equipment valve selection principles

Yongjia Dalunwei Valve Co., Ltd recommends that you refer to the following basic principles of valve setting and selection for some chemical devices:

1. Physical property

1.1 Material state

 The material status of a gaseous material includes data on physical properties, whether it is a pure gas or a mixture, whether there are droplets or solid particles, and whether there are easily condensed components.

1.2 Other properties; Including corrosiveness, toxicity, solubility of valve structural materials, whether flammable and explosive and other properties. These properties sometimes not only affect the material, but also cause special requirements on the structure, or the need to improve the grade of the pipe.

2. Operating conditions

2.1 According to the temperature and pressure under normal working conditions, it is also necessary to combine the working conditions of opening and stopping or regeneration.

 When the system regeneration temperature is much higher than the normal temperature, but the pressure is reduced, for this type of system, to consider the combined effect of temperature and pressure.

 The degree of continuity of operation. That is, the frequency of valve opening and closing also affects the requirements for the degree of wear resistance, and the system with more frequent switching should consider whether to install double valves. Valves with very low switching frequency need to consider the problem of valve jam.

2.2 The environment of the valve: outdoor in cold areas, especially for chemical materials, the valve body material is generally not cast iron but cast steel (or stainless steel).

3. Valve function

3.1 Cut off: Almost all valves have a cut off function. Simply used to cut off without regulating the flow can be selected gate valve, ball valve, etc., require rapid cut off, then plug, ball valve, butterfly valve, etc. More suitable. The stop valve can both adjust the flow and cut off. Butterfly valves can also be suitable for large flow adjustment.

3.2 Change the flow direction: The choice of two-way (channel L-shaped) or three-way (channel for shape) ball valve or cock can quickly change the flow of materials, and because a valve plays the role of more than two through valves, it can simplify the operation, make the switch accurate, and reduce the space occupied.

4.The power of the switching valve

4.1 The vast majority of the valves operated in situ use handwheels, and for those with a certain distance from the operation, sprockets or extension rods can be used. Some large diameter valves have motors in the valve design due to excessive starting torque. In the explosion-proof area to use the corresponding grade of explosion-proof motor.

4.2 Remote control valve: The types of power taken are pneumatic, hydraulic, electric, etc., which can be divided into solenoid valves and motor driven valves. The choice should be based on the need and the energy that can be provided.