Stub End Solutions

It is often impractical to excavate directly above a main or tee piece. This may be because the main is located under a busy junction or is in a sensitive area such as near a petrol station or where disruption caused by the work would be unacceptable.

The Steve Vick International (SVI) Contract Service can offer a number of solutions to the problems associated with these problematic operations, using various remote methods.

Stub End Abandonment (Remote FOAMBAG™)

For the secure and final abandonment on short stubs of live gas main, Live Gas Stub End Abandonment (or Remote FOAMBAG™) is a well proven technique deployed by the SVI Contract Service team.

The technique is remotely carried out from a safe location and is suitable for use on low pressure systems from 3”-12” diameter; typically employed on short ‘stub ends’ of two to 20 m in length.

CCTV equipment is used in combination with the SVI FOAMBAG™ technique to complete the sealing off operation.

SEALBACK®

Sealback is a technique used by the Contract Services to remotely carry out live mains replacement. The technique is especially applicable for traffic sensitive locations.

Live mains replacement using the Sealback® technique

P.E pipe is inserted from a remote location (3m-13m) into an old cast iron main. A SEALBACK™ nose cone is inserted into the end of the P.E pipe which in turn is inserted into the old cast iron main through a gland box.

Gas supplies to customers are uninterrupted while the operation takes place and the final gas seal is achieved through the introduction of SVI patented expanding foam into the annular space.
 

 
 

Advantages of using the Sealback technique include:

  • Reduced project costs
  • Reduced time customers are off gas
  • Reduced disruption to traffic

Pipe Inspection

CCTV camera system used for pipe inspection of PE and metallic mains

CCTV camera surveys are possible on 3”-18” metallic pipe and 63mm-180mm P.E pipe. The CCTV systems are live gas approved and enable accurate mapping of internal mains; quickly identifying any obstructions, poor pressure or leaks.

SVI flowstopping techniques can be used to stop gas flow where needed or the camera can be inserted through a 2” BSP tapping using a Wask Tee Set.

Mapping internal pipework can prevent unnecessary excavation, and ultimately reduce costs. The footage produced is in colour and the technology used is ‘auto uprighting’ to ensure a true image of the main is received.