Inflatable Plug Warning
Maximum head pressures that a pipe plug may hold back can only be estimated. Pressures are influenced by many factors including fluid in the pipe, coefficient of pipeline friction, pressure required to inflate the plug, and the length of the inflated plug. Generally, an inflatable plug inserted fully into pipeline will begin slipping between 50% and 80% of the inflation pressure, but even 50% may be high with some liquids. The inflation pressure is also subject to temperature change and debris or protrusions in the pipeline that could rupture the plug. The inflation pressure must be monitored and plugs anchored and/or mechanically blocked when slippage may cause property damage or injury. NEVER use a test pressure greater than the capacity of the weakest pipe or component in the system.