FRP Pipe Supports Types Spacing and Design Considerations

Why Are FRP Pipe Supports Important?

FRP piping has a relatively lower modulus of elasticity than steel, meaning it can behave differently under bending and external loads. As a result, simply applying steel pipe support spacing to an FRP piping system may lead to excessive deflection or other design issues.

Properly designed supports help distribute the pipe load over an adequate contact area. They also help prevent excessive sagging, vibration, and localized stress that could affect the piping system during operation. Support design becomes particularly important when the pipeline contains heavy fluids, operates at elevated temperatures, includes valves or fittings, or has long horizontal runs.

Types of FRP Pipe Supports

The type of FRP pipe support depends on the function required and the piping configuration. Common support arrangements include weight supports, guides, and anchors.

1. Weight Supports

Weight supports carry the vertical load of the piping system. They are commonly positioned beneath horizontal pipe sections to transfer the pipe and fluid weight to the supporting structure. The support should provide sufficient contact area rather than concentrating the load at a small point.

2. Pipe Guides

Guides help control lateral movement while allowing the pipe to move in the intended direction. They can be important in systems where thermal expansion and contraction need to be accommodated. The guide arrangement should prevent unwanted sideways movement without creating excessive localized stress.

3. Pipe Anchors

Anchors restrict movement at designated locations and divide a piping run into controlled expansion sections. Anchor locations need to be established as part of the overall piping design because excessive restraint can transfer significant loads into the pipe or connected equipment.

4. Pipe Clamps and Saddles

Clamps and saddles can be used to hold and support FRP piping. Because FRP can be sensitive to concentrated loads and abrasion, the contact surface should be properly designed. Elastomeric liners are commonly recommended between the support and FRP pipe to reduce abrasion and provide a more uniform contact surface.

FRP Pipe Support Spacing

FRP pipe support spacing should not be selected using one universal distance for every project. The required spacing depends on pipe diameter, wall thickness, mechanical properties, fluid density, temperature, support configuration, and allowable deflection.

For example, ISO 14692 guidance provides indicative span values for GRP pipes filled with water, ranging from approximately 2.0 m for a 25 mm nominal diameter pipe to around 6.0 m for a 600 mm pipe under the stated design conditions. These values are guidance rather than a universal spacing table for every FRP piping application. Actual FRP pipe support spacing should therefore be confirmed using the pipe manufacturer's technical data and project-specific engineering calculations.

Key FRP Pipe Support Design Considerations

Several factors should be evaluated when developing an FRP pipe support design.

Pipe Size and Construction

Pipe diameter, wall thickness, laminate construction, and mechanical properties influence the allowable span. Larger pipes do not automatically mean that supports can be spaced farther apart without checking the design conditions.

Pipe and Fluid Weight

The support system needs to carry both the empty pipe weight and the operating weight of the contained fluid. Heavy fluids can significantly increase the load on horizontal piping. Other components such as insulation may also add weight and should be included where applicable.

Deflection

Excessive deflection can cause sagging and affect the alignment of the piping system. Support spacing should therefore be checked against the allowable deflection for the specific pipe. ISO 14692 guidance, for example, considers a deflection criterion of 0.5% of span or 12.5 mm at the center, whichever is smaller, under its stated assumptions.

Temperature and Thermal Expansion

FRP piping can expand and contract as operating temperature changes. The support arrangement should allow the intended movement while preventing excessive lateral movement or unwanted loads on connected equipment. Anchors and guides should therefore be positioned based on the thermal movement analysis rather than simply installed at convenient structural locations.

Fittings and Heavy Components

Valves, pumps, flowmeters, and other concentrated loads may require independent support. Their weight should not automatically be transferred to the FRP pipe unless the system has been specifically designed for those loads.

FRP Pipe Support Installation Considerations

During installation, the support surface should be smooth and properly aligned with the pipe. Narrow contact points should be avoided because they can create localized stress on the FRP wall.

Supports should generally be positioned on suitable straight pipe sections rather than directly at fittings or joints unless the engineering design specifically requires another arrangement. Protective liners can also help reduce abrasion between the pipe and support.

Installers should follow the approved piping drawings and the manufacturer's recommended support locations. Any changes to support spacing during installation should be reviewed because moving a support can change the loading and deflection behavior of the piping system.

FRP Pipe Supports vs Metal Pipe Supports

FRP pipes can be supported using suitable metallic structural supports, but the interface between the two materials requires attention. Direct contact between rigid metal and FRP can create abrasion or localized loading.

For this reason, the support design may incorporate wider saddles, protective liners, or other suitable contact materials. The support should also accommodate the outside diameter and movement characteristics of the specific FRP pipe. The objective is not simply to make the support strong, but to distribute loads appropriately while maintaining the required movement and alignment of the FRP piping system.

How to Choose FRP Pipe Supports

Before finalizing an FRP pipe support design, project teams should review:

• Pipe diameter and wall thickness
• Pipe construction and mechanical properties
• Fluid density
• Operating and design temperature
• Operating pressure
• Required support spacing
• Allowable deflection
• Thermal expansion
• Vibration conditions
• Location of valves and fittings
• Anchor and guide requirements
• Support contact area
• Protective liner requirements
• Existing structural steel configuration

The final support arrangement should be based on the specific FRP pipe manufacturer's recommendations and applicable engineering requirements rather than relying on a generic spacing value.

GAJA FRP Piping Solutions

GAJA has experience manufacturing industrial FRP products, including FRP Pipe and FRP Pipe Fittings. Its FRP Pipe manufacturing facility was established in 2017, while GAJA entered the Malaysian market with FRP Pipe Fittings in 2021. GAJA also supplied GRP Pipe for the MRT Jakarta Phase 2 project in 2022. For projects requiring an FRP piping system, support requirements should be considered together with pipe dimensions, operating conditions, fittings, and installation requirements.

If you need assistance discussing FRP pipe, fittings, support requirements, or project-specific piping applications, you can contact GAJA to discuss your project requirements with the team.

FAQ

1. What are FRP pipe supports?

FRP pipe supports are components used to carry and stabilize FRP piping while controlling deflection, movement, and vibration.

2. How is FRP pipe support spacing determined?

FRP pipe support spacing depends on pipe diameter, wall construction, fluid weight, temperature, mechanical properties, allowable deflection, and the support configuration. Manufacturer recommendations should be followed.

3. Can FRP pipes use steel supports?

Yes. Suitable structural steel supports can be used, provided the contact area, protective lining, pipe movement, and localized stress are properly considered.

4. Do FRP pipes need guides and anchors?

Depending on the piping design, guides and anchors may be required to control thermal and lateral movement. Their location should be determined through the piping design rather than installed arbitrarily.

5. Why should FRP pipe supports have a protective liner?

A suitable liner can reduce abrasion and help distribute contact pressure between the support and FRP pipe. This is particularly important where rigid support materials could create localized stress or surface wear.