How to Use Shims in Pipe Supports

Shims are used in pipe supports to correct alignment, adjust elevation, and fill gaps between the pipe and its support structure. Proper shim installation is critical for pipeline longevity and safety. This guide covers everything you need to know about using shims in pipe supports.

When Do Pipe Supports Need Shims?

• When the pipe sits higher or lower than the design elevation
• When supports are not perfectly level after installation
• When thermal expansion changes pipe position
• When fabrication tolerances create gaps
• When foundation settling causes misalignment

Step-by-Step Shim Installation

1. Measure the gap between pipe and support using feeler gauges
2. Select shim thickness to match the measured gap
3. Choose shim material compatible with pipe and support materials
4. Cut shim to match the full width of the support contact area
5. Place shim between pipe and support saddle
6. Verify alignment after shim placement
7. Tack weld or secure shim to prevent movement
8. Document installation in your shim tracker

Types of Pipe Supports That Use Shims

• Saddle supports — shims placed on top of the saddle
• Spring supports — shims under the spring can assembly
• Pipe shoes — shims between shoe and structural steel
• U-bolt clamps — shims under the pipe at clamp points
• Pipe rack supports — shims on structural beams

Shim Selection Guidelines

Always select shims based on: required thickness, material compatibility, temperature rating, and corrosion resistance requirements. For stainless steel piping, use stainless steel shims. For carbon steel piping in non-corrosive environments, carbon steel shims are acceptable.