Inflatable stopper bags

Inflatable stopper bags: overview

The inflatable stopper bags are used to stop off medium- and high-pressure gas pipelines. Type A is a single bag (DN50 to 1000 mm / 2"-40"), fitted with a valve with nipple and standard rubber plug. Type B is a single bag with a mechanism for measuring the pipeline's internal pressure (DN50 to 600 mm). Type C combines double bags with doubled safety: each bag has an individual air supply and a single pipe drilling is enough (DN50 to 400 mm). Type D is a single bag for higher pressures, with a terylene sheath (DN50 to 600 mm).

The basic equipment varies by type: one or two valves with nipple(s), pressure gauges for type C, standard rubber plugs (except the G model) and a terylene sheath for type D. Several models are available (1/2; S/L/O; G; G/P).

What they are for

To work on a gas main without emptying the whole network, the work section must be isolated. The stopper bag, inserted through a tapping and then inflated, blocks the pipe on either side of the work: repair, connection, replacement of a section.

Which type to choose

The choice depends on diameter, pressure and the level of safety required. Type A covers the widest diameter range. Type B allows the pipe pressure to be monitored during the work. Type C doubles the seal through a single tapping, for operations where a leak would have the most serious consequences. Type D is designed for higher pressures.

Inflatable stopper bags: technical specifications

Inflatable stopper bags: documentation