Pipe in Pipe Waterstop Seal

Waterstop Seals

Waterstop Seals

Pipe in Pipe Waterstop Seals

The SIStop™ Pipe-In-Pipe Waterstop Seal provides a field proven solution for isolating a section of flooded annulus by preventing water passage to the adjacent Pipe-In-Pipe sections during installation and normal operation.  The Waterstop Seal resists the maximum external hydrostatic pressure without damage or detriment to long term integrity should the outer pipe be breached due to impact, corrosion or other failure.

Each assembly comprises two sealing elements and a mechanical clamp assembly. The mechanical clamp anchors the assembly onto the inner pipe to prevent any axial movement of the waterstop assembly should a breach of the outer pipe occur. The clamp assembly incorporates integral high strength precision locking collets. The mechanical clamp also allows the seals to be positioned at any point along the inner pipe.

The SIStop™ Pipe-In-Pipe Waterstop has an extensive track record. Over 600 seals have been successfully installed in 10 years. The seal assembly is suitable for j-lay, s-lay and reel lay.

All SIStop™ assemblies are designed in house and subjected to a factory acceptance test at Subsea Innovation to a client approved procedure. This test is performed with sections of project inner and outer pipe, modified by Subsea Innovation specifically for testing purposes. A full representation of the bellmouth and riser / umbilical is manufactured and pull-in tests and activation pressures reproduced.

Technical Specification

  • Inner pipe sizes: 6” to 14” NS
  • Outer pipe sizes: 8” to 18” NS
  • Test pressures: 0 to 500 bar.g
  • Operating temperatures: upto 170 degC
  • Activation: automatic
  • Installation into outer pipe: during pull-in operation

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