Why Travel Stop Installation and Removal Matters
Improper handling of travel stops during spring support installation is one of the most common causes of startup issues in piping systems. If not removed or adjusted at the right time, these mechanical restraints can lock the spring in place, preventing thermal movement and introducing stress into the pipeline.
The result? Cracked welds, failed supports, or misaligned pipe, typically discovered late in commissioning, when field access is limited and delays are costly.
What Are Travel Stops?
Travel stops, also called hydrostatic stops, are temporary restraints installed on variable and constant spring supports to:
- Keep the spring locked during shipping
- Support extra pipe load during hydrostatic testing
During a hydrotest, water is used to pressurize the system. Water weighs more than the gas typically used in operation, so the support must temporarily carry a higher load. Travel stops lock the spring in its “cold” position (before startup), preventing over-compression or coil damage during this test phase.
How Travel Stops Function by Spring Type
- Variable Spring Supports
Travel stops are typically metal bars. These must be fully removed before the system goes into operation. - Constant Spring Supports
Travel stops are bolts. These should be adjusted, not removed, so the support can function properly during thermal movement.
If these steps are skipped, the spring remains locked, which stops the pipe from moving as designed. The trapped stress can propagate through the system, damaging welds, nozzles, or supports.
Travel Stop Common Installation Mistakes
Most issues arise when travel stops aren’t clearly tagged. Field crews misunderstand whether to remove or adjust them, variable and constant springs are treated the same, or communication breaks down between construction and startup teams, leaving springs locked when the system goes live.
Each of these issues stems from lack of clarity or incomplete handoffs between construction, inspection, and startup teams.
Key Field Guidance for Installation Teams
- During Hydrotest: Ensure travel stops are engaged to carry the temporary water load
- Before Startup: Remove stops from variable springs; adjust bolts on constant springs
- Walkdown Ready: Use visual tags or checklists to confirm travel stops are cleared
- Team Coordination: Confirm travel stop status is clearly communicated across construction and startup crews
Real-World Example of Travel Stops Not Removed
On a recent Gulf Coast refinery job, variable spring supports were installed for an elevated, insulated 14-inch pipe. After hydrotesting, the travel stops were never removed. At startup, expansion forces created unexpected load on a nearby anchor point, resulting in misalignment and support bracket damage. Resolving the issue delayed startup by three days and required re-inspection of every spring in that system.
Engineer and Project Manager’s Take
If you’re managing pipe systems with thermal displacement or elevated runs, spring supports are only effective if they’re allowed to move. Travel stops are meant to be temporary. Leaving them in place locks the spring, blocks pipe movement, and shifts stress into the system, often at welds, nozzles, or anchor points.
From an engineering perspective, this is a preventable failure. From a project management perspective, it’s a high-risk RFI waiting to happen. The fix is simple but critical: flag it, inspect it, and verify it during every pre-commissioning walkdown. Doing so avoids startup delays, costly rework, and post-installation repairs.
Related Products
Some common products that come to our customers with travel stops in place are:
- Variable and Constant Spring Supports – Each comes with travel stops pre-installed
- Pipe Shoes – Frequently paired with springs for vertical load distribution
- Slide Plates – Allow lateral movement under guided systems
- Spring Hangers and Rod Assemblies – Used in overhead piping where thermal expansion is expected
Talk to an Engineer
Need help verifying travel stop status or building out a field checklist for your walkdown? Our engineering team supports your project from install through startup.
→ Contact Us and Talk to an Engineer Today