Common faults and troubleshooting methods of PVC pipeline construction and installation

Update:29 Jan 2021

As a commonly used pipe in our lives, PVC pipes are also particular about their construction process. It is not just a simple installation. There are some precautions if you do not pay special attention during the construction process, which may cause subsequent projects. Failure or failure soon.

Precautions for PVC pipe construction and installation

  1. When the small diameter pipe is bonded by solvent, the socket must be rounded to form a bevel, and the fracture should be flat and vertical axis, so that it can be bonded firmly and avoid water leakage.

  2. Generally, PVC pipes with a diameter greater than or equal to 100 mm use rubber ring joints. Before installation, personnel must be arranged to chamfer the pipe socket, and the quality of the rubber ring must be checked.

  3. The trench excavation of traditional pipeline installation only requires that the pipe can be put into the trench and can be sealed. When the original soil layer is not loosened, the cushion layer can be compacted under pressure.

       4. During construction, you can add a saddle-shaped fitting half a two-in-three link, and clamp it with a U-shaped bolt, which thickens the pipe wall, and then directly drill holes on it, and then connect it with an external threaded plastic part .

   5. As a new type of non-metallic pipe, PVC pipe can not detect its specific location with existing metal pipe detection equipment. However, this problem can be easily solved if a wire is buried on the pipe during the pipeline burying facility.

Common faults and troubleshooting methods of PVC pipes

Broken pipe

the reason:

1. Pipeline fractures caused by poor pipe quality; preventive measures: strictly control the purchase to ensure the quality of pipes.

2. Pipeline fracture caused by poor foundation; preventive measures: basic treatment of bad foundation, such as compaction, replacement and setting of concrete or reinforced concrete foundation, etc.; the stones, hard objects, and rock foundation pipes under the pipe should be removed. A 15 cm sand cushion is required underneath.

3. Pipeline fracture caused by temperature stress; preventive measures: the pipe should be covered with soil below the maximum freezing depth of 20 cm, and pay attention to the lateral and the depth of the soil under the pipe; pay attention to timely backfilling in winter construction, and drain the water in time after the hydraulic test ; High temperature construction in summer must be avoided, expansion joints should be installed as far as possible to avoid shrinkage of pipelines.

4. Pipeline fractures caused during construction are not eliminated; preventive measures: construction management must be strengthened, especially in several processes such as pipe trench excavation, foundation treatment, laying and installation, pipe pressure testing, and pipe trench backfilling, etc. .

  Removal method: excavate the backfill. The length of the excavated trench should be about 2.0 meters longer than the length of the broken pipe, cut off the broken part, and use 100-mesh emery cloth to roughen the outer side of the pipe opening in the ditch, the length is about 5-10 cm. Use a flared tube instead of a split tube. The inner diameter of the flared tube is equal to the outer diameter of the inner tube in the trench. The inner wall of the flared tube is roughened with emery cloth, the length is about 6~11 cm, and the adhesive is coated. Lift the ditch tube, cover the ditch tube with the flaring tube, and rotate the flaring tube left and right to make it evenly adhered.

Vacuum break

   Reason: The pipeline system suddenly shuts down when it is running, and a negative pressure (vacuum) occurs, which flattens the pipeline.

  Precautionary measures: The exhaust valve is designed in the pipeline system and installed at the beginning of the pipeline when it is downhill. It is designed to be installed at the end of the pipeline when it is uphill or where the terrain changes greatly.

  Removal method: replace the damaged pipes, install the intake and exhaust valves according to the terrain.

Air resistance destruction

  Cause: In the undulating section of the water pipeline, the inlet and exhaust valves are not installed, resulting in a gas-locked pipe burst.

  Precautionary measures: Intake and exhaust valves must be installed in the mountain or valley pipe section.

  Removal method: replace the damaged pipe and install the exhaust valve according to the terrain.

Interface leakage

the reason:

   1. Cracks in the pipe head cause water leakage.

   2. The lap length of the pipe head is too short or the joint is not firm and leaks water.

  Understanding the common faults of PVC pipes, it is especially important to maintain, handle or replace them to ensure our normal life. We must pay attention to every detail during the installation process to ensure that it can be put into use as soon as possible.