Quick Opening Closure

A quick-opening closure is a pressure- containing component used for repeated access to the interior of a piping system: Quick-actuating or quick-opening closures are those that permit substantially faster access to the contents space of a pressure vessel than would be expected with a standard bolted flange connection.

Quick opening closures are primarily installed on pig launchers and receivers, pressure vessels such as filter units, and blowdowns on vertical vent stacks.

Pig launcher and receiver closures are normally designed to pipeline design codes ASME B31.4 for liquid pipelines or ASME B31.8 for gas pipelines. Quick-opening closures installed on pressure vessels are normally designed to ASME Section VIII, Division 1.