Size, Pressure & Special Routing · Size, Pressure & Special Routing
Large 16–30 inch spiral main
Main distribution
ConnectionCoupling/gasket/flange
SupportEngineered saddles/trapezes
Before you start
- Confirm 16–30 inch diameter, actual section weight, joint type, lifting plan, support design, fitting weight, and route clearance.
- Inspect for ovalizing, dented beads, damaged gaskets, and distorted ends.
- Plan soft-sling lifting and enough control points.
- Verify saddles or trapezes are installed before long sections are released.
Tools and materials
Large spiral sections and fittings, approved coupling, gasket, or flange hardware, soft slings, lift equipment, engineered saddles or trapezes, fasteners, sealant, level, and tag lines.
Lay it out
- Mark centerline, support points, and fitting locations.
- Confirm lift path and swing clearance.
- Plan independent support for heavy fittings.
Set and support it
- Install saddles or trapezes before lifting.
- Use soft slings and spread lifting points.
- Control roll with tag lines.
Make the connection
- 1
Lift and set the first section on permanent supports.
- 2
Bring the next section to the same centerline.
- 3
Align the full circumference.
- 4
Complete the approved joint.
- 5
Seal and inspect the connection.
- 6
Set fitting supports.
- 7
Release rigging slowly and watch for ovalizing.
Check the install
- The shell remains round.
- Support load is carried by saddles or trapezes.
- Heavy fittings have independent support.
- Joints are fully seated and sealed.
- No lift damage remains.
Common mistakes
- Using a narrow sling that dents the shell.
- Letting a heavy elbow hang from the joint.
- Releasing the lift before support is complete.
- Forcing distorted ends together.
Stop and ask
Stop if the lifting plan, support capacity, fitting support, or control method is inadequate for the section size and weight.