I. Introduction to PVC Pipe Products

Polyvinyl chloride (PVC) pipes—often abbreviated as PVC pipes in English—are the earliest type of plastic pipe to be developed and put into practical use. They are manufactured by heating and extruding a mixture of polyvinyl chloride resin combined with auxiliary materials such as stabilizers, lubricants, and color masterbatches. After years of accumulated experience in processing and application, PVC pipes have now established standardized production and processing techniques, along with a comprehensive supporting infrastructure. Coupled with their economic, environmentally friendly, and cost-effective advantages, PVC pipes have become the dominant product among rubber and plastic pipelines.

II. Characteristics of PVC Pipes

Lightweight and easy to handle, load, and unload; PVC pipes are very lightweight, making them convenient to transport, load, unload, and install, thus saving labor costs.

Excellent chemical resistance: PVC pipes exhibit outstanding resistance to acids, alkalis, and corrosive substances, making them highly suitable for applications in the chemical industry.

Low fluid resistance: The walls of PVC pipes are smooth, resulting in low resistance to fluid flow. Its roughness coefficient is only 0.009, which is lower than that of other pipe materials. Under the same flow rate, the pipe diameter can therefore be reduced.

High mechanical strength: PVC pipes exhibit excellent resistance to water pressure, external pressure, and impact, making them suitable for piping projects under various conditions.

Excellent electrical insulation properties; PVC pipes offer superior electrical insulation, making them ideal for use as conduits for wires and cables, as well as for wiring installations in buildings.

III. Application Fields of PVC Pipes

Water supply projects, electrical engineering, and construction engineering. Sewerage projects, telecommunications engineering, and well-drilling projects. Brine projects and natural gas projects. Chemical plants, paper mills, brewing and fermentation plants, and electroplating plants. Agricultural estates, mines, aquaculture farms, highway construction projects, golf course development projects, plastic rafts for fisheries, landscaping and greening projects, and more.

IV. Construction Methods and Precautions for Polyvinyl Chloride (PVC) Water Supply Pipes

Construction method

The TS adhesive application procedure is as follows:

Bevel the male pipe end at a 30° angle on the outer corner, leaving a pipe-end thickness of 1/3t.

Wipe clean the inner wall of the pipe socket and the outer wall of the pipe end within the insertion range, and mark the insertion depth.

Then apply an appropriate amount of rigid adhesive. Once the adhesive has fully evaporated and its adhesion has increased, firmly insert the male pipe into the small-diameter pipe and rotate it by 90° to ensure even distribution of the adhesive. For medium- and large-diameter pipes, you can use a wooden mallet to tap them into place.

After insertion, it should be held in place for about 30 seconds before being moved. The glued area must not be disturbed for at least 2 hours.

After the pipeline installation is completed, water pressure testing can only be conducted 48 hours later. The optimal length of the pipeline for pressure testing should be between 400m and 500m.

Live casing construction method

Bevel the male pipe end at a 20° angle, leaving a wall thickness of 1/4 to 1/3 t at the prepared pipe end; (the pipes are already beveled at the factory).

Wipe the rubber ring and the flexible groove clean, then install the rubber ring into the groove with the larger diameter facing outward.

Mark the insertion length on the male pipe end;

Apply lubricant (such as soapy water or dishwashing detergent) to the inserted portion of the male pipe and to the inner surface of the rubber ring. Then, use a tensioning device to connect the two pipes together.

After the fitting is complete, use a hacksaw blade to check whether the rubber ring has been pushed over.

Construction Precautions

During product handling and loading/unloading, it is strictly prohibited to throw, drop, roll, or drag the items. During transportation, the bottom of the vehicle should be lined with anti-abrasion pads to prevent pipes from being bumped or damaged.

After the trench excavation is completed, the trench bottom must be manually leveled. Any hard objects such as stones must be removed, and fine sand or fine soil should be spread to protect the pipeline.

When connecting live pipe fittings, make sure to insert the rubber ring into the groove with the larger diameter facing inward and the smaller diameter facing outward, to prevent the rubber ring from flipping over.

When installing adhesive-type pipes, apply an appropriate amount of adhesive—do not use too much—to prevent the adhesive from corroding the pipe body and reducing its pressure-bearing capacity.

After connecting pipes and fittings, be sure to reinforce the branch points of the fittings with concrete.

During pipeline pressure testing, it is essential to install air vents at the initial end, highest point, and terminal end to prevent water hammer, which could cause the pipe body to rupture.

When there is a significant temperature difference between the water temperature inside the pipeline and the ground temperature, water should be introduced first. Only after the pipeline is completely filled with water and 24 to 48 hours have passed can the pressure test be carried out.

V. Construction Methods and Precautions for Rigid Polyvinyl Chloride (PVC-U) Pipes Used for Drainage

Construction method

The construction method for solid-wall drainage pipes is the same as that for PVC water supply TS pipes; please refer to the construction method for PVC water supply TS pipes.

When installing PVC double-wall hollow spiral pipes, pay attention to the installation of the hollow spiral pipe sealing ring.

PVC corrugated pipe installation method: During construction, pay attention to installing corrugated pipe rubber rings at the second and fourth grooves on the male pipe end.

For construction precautions, please refer to the national standards.

VI. Construction Methods and Precautions for Insulated Conduit Installation

Construction method

Use a pipe cutter to cut the pipe and trim it neatly.

Use a measuring tape to mark the positions where cold bending is required, then insert the cold-bending spring into the pipe.

Hold both ends of the pipe firmly with your hands, and apply force to bend it to the desired angle. The bending angle should be about 15% larger than the intended angle to prevent rebound after bending, which could affect normal use.

Construction Precautions

Light and heavy-duty electrical conduit cold-bend springs must be used in matching pairs and should not be mixed.