Directly buried compensators, especially directly buried corrugated compensators, are installed to follow a specific set of requirements to ensure that they can work effectively and maintain the safety of the pipeline system. Here are some key installation requirements:
Uses and features：
The directly buried compensator is mainly used for axial compensation of directly buried pipelines, and has strong bending resistance, so the influence of pipeline sinking can not be considered.
Fixed Point and Pipe Configuration：
The pipe shall be equipped with a compensator between two high fixed points, one at the end of the straight section and the other at the branch of the pipe.
For a long straight pipeline section without branches, there can be no fixed point between the two compensators, and the natural "stationary point" of the pipeline can play the role of fixed point.
The stationary point refers to the fixed point of the pipe between the two compensators. When the pipe diameter and buried depth are consistent, the stationary point is equal to the distance between the two compensators.
Maximum installation length：
The maximum installation length of the pipe shall ensure that the frictional force does not exceed the elastic force under the allowable stress of the pipe.
The distance between the compensator and the fixed point shall not exceed the maximum installation length Lmax of the pipe.
Pre-installation inspection：
Check the model, specification and pipe configuration of the compensator to ensure that it meets the design requirements.
For the compensator with the inner sleeve, verify that the direction of the inner sleeve is consistent with the direction of the medium flow.
Installation Environment Preparation：
Before installation, ensure that the bottom of the pipe trench is flat so that the compensator and the connected directly buried insulated pipe can be smoothly aligned.
Thermal insulation and landfill：
When the insulation pipe is buried underground, it should be filled with sand with a particle size of less than 20mm around it, and then covered with original soil, and the thickness of filling sand should not be less than 200mm.
The buried depth of the top of the insulation pipe is generally no more than 1.2 meters, but try not to be less than 0.7 meters.
Avoid improper handling：
It is strictly prohibited to use the method of compensator deformation to adjust the installation excess tolerance of the pipeline, so as not to affect its normal function and reduce the service life.
During the installation process, the welding slag is not allowed to splash onto the surface of the corrugated shell to avoid other mechanical damage to the corrugated shell.
Guide bracket：
When using directly buried compensators, it is generally not necessary to set guide brackets, unless special design requirements.
Except for the designated locations, the rest of the parts shall be insulated.
External dimension inspection：
Perform a cosmetic dimensional inspection to ensure that the perimeter of the nozzle meets the allowable deviation range.
Fixed end positioning：
The fixed end should be close to the fixed bracket to ensure that the core tube end can move freely.
Avoid cold tightness：
The installation of the directly buried compensator does not need to be cold tight, nor does it need to be welded after the whole line of steel pipes is connected, and then the pipes equal to the length of the expansion joint are cut off.
During the installation process, it is important to adhere to the specific installation guidelines and engineering design standards provided by the manufacturer. These requirements help ensure the correct installation of the compensator, which improves the reliability and safety of the plumbing system.