Installation requirements for directly buried compensators are specificated to ensure that the compensator works properly while protecting the pipeline system from stress damage caused by thermal expansion and contraction. Here are some key requirements and specifications for directly buried compensator installation sorted out according to the information you queried before:
General Installation Requirements
Inspection and Verification：
Before installation, check that the compensator model, specification, flow direction symbol, and line configuration meet the design requirements.
Verify that the liner flow direction of the compensator coincides with the media flow direction to reduce fluid resistance and vibration.
Appearance check：
Check the permissible deviation of the perimeter of the connector to ensure that the dimensions meet the standard (e.g. nominal diameter DN1000 ± 6mm, DN1000 or less ± 4mm).
Ground preparation：
Prior to installation, tamp the bottom of the trench to ensure that the corrugated compensator and directly buried underground insulation pipe are level.
Fixing and guiding：
The compensator must be mounted on a stable support structure that ensures that the equipment is not damaged by swaying or instability.
The installation position shall have guide brackets to control the axial displacement of the pipe and avoid the lateral displacement.
Ventilation and heat dissipation：
The installation location should have good ventilation conditions to dissipate heat and reduce the temperature of the equipment, and ensure the proper operation of the equipment.
Grounding and Protection：
The compensator must be properly grounded to prevent electrical breakdown and personal safety issues.
The installation location should have appropriate protective measures, such as protective covers, safety railings, etc., to prevent accidental injuries caused by personnel misoperation or contact with equipment.
Specific installation requirements
Maximum installation length：
The distance between the compensator and the fixed point shall not exceed the maximum installation length Lmax of the pipe, ensuring that the frictional force does not exceed the elastic force under the allowable stress of the pipe.
Thermal expansion compensation：
Ensure that the compensator can absorb the displacement of the pipeline due to thermal expansion and contraction, especially in directly buried heating pipelines, and consider the large temperature difference caused by the soil insulation effect.
Insulation requirements：
When the thermal insulation pipe is buried in the ground, apply sand with a particle size less than 20mm to fill the surroundings, and then cover the original soil, and the thickness of the filling sand is not 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.
Pre-stretched or pre-compressed：
Depending on the ambient and medium temperature, the compensator may need to be pre-stretched or pre-compressed to reserve sufficient compensation space.
Avoid improper handling：
It is strictly prohibited to use the method of compensator deformation to adjust the installation excess tolerance of pipeline, so as not to affect the normal function of compensator and reduce the service life.
Other Precautions
Ensure that no damage is caused to the corrugated portion of the compensator during installation.
Installation should be carried out in accordance with the manufacturer's recommended length unless installation tolerances have been specified by the system designer.
Depending on the specification, internal pressure compensators may need to be pre-stretched or pre-compressed according to ambient temperature prior to installation.
The above specifications and requirements should be regarded as basic guidelines, and specific installation details and procedures may vary depending on the manufacturer's instructions and engineering design. When installing a direct buried compensator, it is important to always follow the latest industry standards and manufacturer's guidance.