One-time expansion joints

One-Time Expansion Joints is a one-off axial expansion joint specially developed for installation in district heating systems, where the pipeline’s temperature variations are absorbed as tensile and compresive stresses in the steel pipe instead of expansion movements.
The One-Time Expansion Joints are delivered 100% pre-set according to suppliers standard movements. If needed it could also be delivered pre-set according to customers calculated reduced movements, and fixed with tack weldings until pressure test have been approved. The movement will be marked with line on shroud, and before the pipeline is heated up with district heating water the tack welding should be removed.
When One-Time Expansion Joints are free of damage, correctly installed and filled with district heating water at mean tempeature, it should be locked by fully welding at the non-welded end of shroud. Once the One-Time Expansion Joints are locked, and have absorbed the full movement, it has function as a normal pipe.
Leak test of the shroud welding can be done from the leak test hole placed on the middle of the conical shroud (small screw). Leak test hole must be closed with welding after leak test inspection.

FEATURES:                     ONE-TIME RANGE:

•Maintenance free                 • Size: DN25 – DN1000
• Sealing Shroud                     •Temp.: +120°C
•Easy installation and isolation          •Pressure: 25 BarG
• Can be delivered with costumized pre-setting