Sep.20.2024
The efficient and reliable operation of pipelines is essential across various industries, and the proper installation of valves plays a crucial role in ensuring fluid control and system safety. In this comprehensive guide, we explore the five common valves installation vital for pipeline functionality: Safety Valve, Pressure Reducing Valve, Check Valve, Globe Valve, and Gate Valve. Each valve type serves a specific purpose, and understanding their correct installation procedures is paramount for optimizing performance, preventing accidents, and maintaining the integrity of fluid transport systems.
01 Safety Valve
1. Before installation, a thorough inspection of the product must be conducted to verify the presence of a certificate and product manual, ensuring clarity on the factory-set pressure conditions.
2. Safety valves should be positioned near platforms whenever possible for easy inspection and maintenance.
3. Install safety valves vertically, ensuring that the medium flows from bottom to top. Check the verticality of the valve stem.
4. In general, isolation valves should not be placed before or after safety valves to ensure safety and reliability.
5. Pressure relief for safety valves:
- For liquid media, discharge into pipelines or closed systems is typical.
- For gas media, discharge generally occurs outdoors into the atmosphere.
6. For oil and gas media, discharge into the atmosphere is common. The vent pipe outlet for safety valve discharge should be at least 3m above surrounding structures. However, in specific cases, discharge into a closed system may be required for safety.
7. The diameter of the vent pipe, if smaller, should be equal to the inlet diameter of the valve. The outlet diameter of the discharge pipe should not be smaller than the valve outlet diameter. The discharge pipe should lead outdoors and be installed with bends directing the pipe outlet towards a safe area.
8. When installing safety valves with an opening weld connection to equipment and pipelines, the opening diameter should match the nominal diameter of the safety valve.
02 Pressure Reducing Valve
1. For vertically installed pressure reducing valve assemblies, place them along the wall at a suitable height above the ground. For horizontally installed assemblies, place them on a durable operating platform.
2. Use support brackets on the outside of two control valves (commonly used as stop valves), fixed inside the wall to form a frame. Side pipes should be clamped on the frame for leveling.
3. Pressure reducing valves should be installed upright on horizontal pipelines without tilting. The arrow on the valve body should indicate the direction of medium flow and should not be installed in reverse.
4. Install stop valves and high and low-pressure pressure gauges on both sides to observe pressure changes before and after the valve. The diameter of the pipeline after the pressure reducing valve should be 2#-3# larger than the inlet diameter, and a bypass pipe should be installed for maintenance.
5. For membrane-type pressure reducing valves, the pressure equalization pipe should be connected to the low-pressure pipeline. Install a safety valve for low-pressure pipelines to ensure system safety.
6. For steam pressure reduction, a drain pipe should be installed. For pipeline systems with high purity requirements, install a filter before the pressure reducing valve.
7. After the installation of the pressure reducing valve assembly, conduct pressure testing, flushing, and adjustment according to design requirements for both the pressure reducing valve and safety valve. Mark adjustments accordingly.
8. When flushing the pressure reducing valve, close the inlet valve and open the flushing valve for cleaning.
03 Check Valve
A check valve, also known as a non-return valve or one-way valve, is a valve that automatically opens and closes under the influence of pressure differences before and after the valve. Its function is to allow fluid to flow in only one direction and prevent the medium from flowing backward.
Check valves come in different structures, including lift-type, swing-type, and butterfly-type. Lift-type check valves can be further categorized as horizontal and vertical.
When installing check valves, attention should be paid to the direction of the medium flow, and they should not be installed in reverse.
04 Globe Valve
A globe valve controls the opening and closing of the valve through the movement of the valve disc. By changing the gap between the valve disc and the seat, the size of the channel cross-section is altered to regulate fluid flow or shut off the fluid path. The installation of globe valves must consider the direction of fluid flow.
The principle to be followed when installing globe valves is that the fluid in the pipeline passes through the valve hole from bottom to top, commonly known as "low in, high out," and reverse installation is not allowed.
05 Gate Valve
Gate valves, also known as gate plate valves, control the opening and closing of the valve using a gate plate. They regulate the flow and open or close the pipeline by changing the cross-sectional area.
Gate valves are commonly used for fully opening or fully closing operations in pipeline systems. There is generally no directional requirement for the installation of gate valves, but they should not be inverted.
