ALH Large Diameter Bag Off

The ALH large-diameter bag tubes provide a safe and effective method for flow-stopping 14” to 24” diameter gas mains.

Large-diameter bag tubes are a safe, easy-to-use and cost-effective flow-stopping system for maintaining, repairing and modifying distribution networks whilst preserving the continuity of supply. The entire procedure is totally gas-free, carried out through an arrangement of valves.

PES supplies the complete package, including drilling machines, plug insertion equipment, flowstopping bagtubes and bags. The aluminium construction reduces weight and makes the flowstopping equipment easily transported and positioned onto the gas main.

System Parameters

14” to 24” diameter mains
Maximum operating pressures dependent on the main size
Ideal for use with the ALH Bond & Bolt saddle system
Flow rate up to 5 metres per second
Standard System 3 Iris Stop valve, adaptor and spool connector
Lightweight aluminium construction
Can also be used as the second position for Iris StopALH Large diameter bag off
Strong bags for additional safety (GIS/E20)

Large Diameter PE Flowstopping

The large-diameter bagtube system offers an alternative to squeeze-off on polyethylene (PE) mains. On PE mains, bag insertion is via a fused branch saddle, which can be permanently plugged to remove the entry valve after the operation.

If you’re interested in our ALH Large Diameter Bag Off process, get in touch and our dedicated team will be happy to answer any questions you may have.