Emergency shut-off valve - application selection
Time: September 14, 2020 18:46:08 Source: Yonglong Valve Reading: zero second
Emergency shut-off valve - application selection
In response to emergencies in flammable and corrosive fluid pipeline system, the emergency shut-off valve is the first to bear the brunt. Its main role is to quickly cut off the medium flow of storage tank equipment and pipeline system. Prevent leakage or fire. It can also be used to control the flow of various fluids such as air, water, steam, various corrosive media, mud, oil, liquid metal and radioactive media. As it is very important to select a suitable shut-off valve for the pipeline system, it is also crucial to understand the characteristics of the valve and the steps and basis for selecting the valve.
The main body of the emergency cut-off valve includes: cut-off valve, ball valve, gate valve, butterfly valve, which is used to connect or cut off the pipeline medium. The driving device is the valve operated by manual, electric, hydraulic and pneumatic means. The nominal pressure of the valve shall be selected according to the actual pressure of the pipeline. The specification of the valve shall be selected according to the inner diameter of the pipeline, and the valve disc seal and packing seal materials shall be selected according to the temperature of the medium.
1. The stop valve is applicable to the pipeline with less strict requirements for fluid resistance, that is, the working condition with little consideration for pressure loss.
2. The ball valve is not suitable for flow regulation, but it is suitable for situations requiring quick opening and closing, which is convenient for emergency shutdown.
3. The gate valve is suitable for medium containing granular solids and high viscosity, as well as for venting and low vacuum systems in addition to steam, oil and other media.
4. The pressure loss of butterfly valve is relatively large compared with that of gate valve and ball valve, so butterfly valve is applicable to the pipeline system with less strict pressure loss requirements.
1. Flange: the valve body is equipped with a flange, and the valve is connected to the pipeline with a flange.
2. Welding: the valve body is equipped with welded junction, and the valve is connected with the pipeline by welding.
3. Ferrule: valve connected with ferrule and pipeline.
4. Thread: The valve body is equipped with internal thread or external thread, and is connected with the pipeline by thread.
5. Clamp: a valve with a clamp on the valve body and connected with the pipeline by clamp.
The structural characteristics of the emergency shut-off valve determine some structural characteristics of the installation, maintenance, and other methods of the valve. The structural characteristics include: the structural length and overall height of the valve, and the connection form with the pipeline (flange connection, threaded connection, clamp connection, external thread connection, welding end connection, etc.); Form of sealing surface (insert ring, threaded ring, surfacing, spray welding, valve body); Valve stem structure (rotating rod, lifting rod), etc.
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