It is a common practice to install the compensator on the upper side of the valve (i.e., upstream), and this arrangement helps protect the valve from thermal expansion and contraction of the pipe and other mechanical stresses. Here are some key considerations and advantages about installing the compensator on the upper side of the valve:
Reason for mounting on the upper side of the valve
Protective valve：
The compensator is able to absorb the expansion and contraction of the pipe due to temperature changes, reducing the stress transmitted to the valve, thereby extending the life of the valve and ensuring its sealing performance.
Optimize system layout：
Installing a compensator upstream of a valve can help better plan the layout of your piping system, especially if you need to deal with complex displacements or vibrations.
Prevent stress concentration：
By providing a compensator in front of the valve, the valve can be avoided from being directly subjected to thermal or other mechanical stresses from the pipeline, preventing the stress from concentrating at the valve connection.
Easy maintenance：
If the valve needs to be replaced or overhauled in the future, a compensator located upstream can make operation easier because the compensator can absorb the displacement generated during disassembly.
Reduce the water hammer effect：
The presence of compensator can alleviate the water hammer effect that may be triggered when the valve is closed quickly to some extent, and reduce the impact on the whole pipeline system.
Installation Considerations
Maintain an appropriate distance：
A certain distance should be maintained between the compensator and the valve to ensure that the compensator can be freely expanded and contracted without being restricted by the valve. The exact spacing depends on the type and specification of the compensator, as well as the layout of the piping system.
Fixed bracket and guide bracket：
Install fixed brackets and guide brackets in appropriate positions on both sides of the compensator to ensure that the compensator only moves in the intended direction and prevents lateral displacement or torsion. This also helps protect the valve from unwanted stresses.
Pre-stretched or compressed (if necessary)：
For some compensators that require "cold tightening", appropriate pre-stretching or compression is performed at installation according to design requirements to achieve optimal compensation at operating temperatures.
Follow Manufacturer Guidelines：
Proper installation is ensured by strictly following the installation manuals and technical specifications provided by the manufacturer of the compensator and valve.
Application Scenario Example
Steam piping system: In steam delivery lines, compensators are typically installed upstream of shut-off or regulating valves to cope with pipe expansion and contraction due to temperature changes.
Chemical industry: For piping systems containing corrosive media, compensators protect expensive and sophisticated control valves from mechanical stress damage.
Long distance conveying pipelineIn long-distance pipelines such as oil and natural gas, compensators are often installed before critical valves to accommodate displacements caused by foundation settlement and temperature changes.
Summary
It is reasonable and effective to install a compensator on the upper side of the valve, which not only helps protect the valve, but also optimizes the performance and safety of the entire pipeline system. However, the specific installation scheme should be flexibly adjusted according to the actual working conditions and equipment characteristics, and strictly comply with relevant standards and technical specifications. Through reasonable planning and correct installation, the compensator and valve can be ensured to work together to guarantee the stable operation of the pipeline system.