Tip #10 · Supports
A guide without a stop is half a support system.
Always design supports for hydrotest weight (water-filled), not just operating weight. A gas line weighing 30 kg/m in operation may weigh 150 kg/m when water-filled for testing.
Guides control lateral movement; stops control axial movement. Using only guides on a thermal expansion loop means the pipe will find its own stop — usually a structural beam, an adjacent nozzle, or a piece of equipment it was never meant to touch.
The failure mode
If support spacing was designed for operating weight only, the pipe sags or supports fail during hydrotest. Many project specs require hydrotest weight as the design basis for exactly this reason. Check your project spec on day one.
The takeaway: Support systems are systems. A guide without a coordinated stop is a design intent waiting to be violated by thermal expansion. Work with your stress engineer to define both — they are two halves of the same answer.
