FRP pipe installation guide / how to install fiberglass pipe insulation

FRP pipe installation guide / how to install fiberglass pipe insulation

Fiberglass reinforced plastic (FRP) pipes are widely used in municipal water supply and drainage, chemical engineering.

power generation, and environmental protection projects due to their corrosion resistance, lightweight, high strength, and long lifespan.

However, installation quality often determines the long-term reliability of a piping system. 

Even the highest-quality products can suffer from leakage, deformation, and even system 

failure if improperly installed. This article will introduce the standard installation process and common connection methods for FRP pipes to help you avoid potential installation hazards.

1. Preparation before installation

To ensure a smooth installation, each step from site survey, material inspection to tool preparation must be closely linked and standardized.

 

1.1 Site Survey

 

Before installation, a detailed on-site survey of the route should be conducted. Focus on verifying that the trench dimensions, slope, and surrounding environment meet design requirements. Underground obstructions should also be checked to prevent deviations during construction.

 

1.2. Pipe and Fitting Inspection

 

Upon arrival at the construction site, the specifications, models, and quantities of the pipes and fittings should be individually verified to ensure they conform to the design.

 

Also, check that the inner and outer walls are smooth and undamaged, and that the sockets and spigots must be free of defects such as cracks, notches, or deformation.

 

1.3 Trench Preparation

 

The trench bottom should be flat, solid, and continuous. To prevent sharp rocks from scratching the pipe body, a 100-200mm thick layer of medium-coarse sand should generally be laid on the bottom to ensure uniform load distribution.

 

1.4 Tool Preparation

 

All necessary equipment for installation should be prepared in advance, including a crane, soft sling, manual hoist, fall chain, crowbar, and cleaning tools.

 

Note: Direct lifting with wire rope is strictly prohibited to avoid damaging the FRP pipe surface.

 

2.Common connection methods

 

FRP pipes can be connected in a variety of ways, with socket-and-spigot bonding and flanged connections being the two most common.

 

The former is economical, provides excellent sealing, and is suitable for low- and medium-pressure systems; the latter is easy to assemble and disassemble, making it suitable for high-pressure applications or those requiring maintenance.

 

 

2.1 Socket-and-socket Bonding (O-Ring Sealed Connection)

 

This is the most widely used connection method, offering simple operation and reliable sealing.

 

Standard procedures are as follows:

 

Cleaning the joint: Remove dust, moisture, and oil from the inner and outer surfaces of the socket and keep them clean and dry.

 

Lubricating: Apply soapy water or silicone grease evenly to the socket and O-ring. Do not use petroleum-based lubricants such as motor oil, as they may corrode the rubber.

 

Installing the sealing ring: Place the sealing ring into the socket groove and ensure it fits smoothly and without twisting.

 

Marking the insertion line: Measure the insertion depth and mark the socket end to ensure a secure connection.

 

Butt-jointing: Use a crane or manual labor to align the centerline and slowly push in until the marked line is flush with the socket end.

 

Checking the seal: Use a probe to check the gap to confirm the sealing ring is correctly positioned and securely fastened.

 

 

2.2 Flange Connections

 

Flange connections are removable, high-pressure-resistant, and highly robust. They are commonly used for valve connections, equipment inlets and outlets, or high-pressure pipe sections.

 

Installation key points are as follows:

 

Alignment and Sealing: Align the two flanges, sandwiching a rubber or PTFE gasket between them to ensure the gasket is centered.

 

Tightening: Tighten the nuts in three or more diagonal steps to ensure uniform force on the gasket and prevent unilateral stress.

 

Torque Control: Tighten to the specified torque to avoid excessive force and crushing the fiberglass flange.

 

3.Installation precautions and quality control

 

 

3.1Lifting and Transportation

Wide nylon slings or canvas straps must be used; wire ropes must not be used to prevent localized damage.

 

3.2Backfill

Use soft soil or gravel for backfill, avoiding materials with sharp corners and rocks. Tamp the backfill layer by layer from both sides simultaneously to ensure uniform stress distribution and prevent displacement.

 

3.3Environmental and Temperature Control

The bonding temperature should be between 5°C and 40°C. Temperatures that are too low will affect the curing of the adhesive, while temperatures that are too high will reduce its strength.

 

3.4Hydraulic Pressure Test

A hydrostatic test should be performed after installation. When filling the water tank, exhaust the air first. The pressure should be increased slowly and steadily, and sudden pressure increases should be avoided to prevent impact damage.

 

4. Summary

 

Fiberglass pipe installation is more than just a mechanical operation; it's a project that demands meticulous attention to detail and experience.

Only by strictly adhering to installation specifications and controlling construction conditions can the full benefits of fiberglass pipe be realized.

For large or high-pressure systems, it's recommended to select a team with professional installation experience to ensure system safety and long-term stable operation.