GAS PIPELINE CAVITY DRYING METHOD AFTER HYDRAULIC PRESSURE TESTS ARE COMPLETED Russian patent published in 2009 - IPC F26B7/00 F26B5/04 

FIELD: heating systems, drying.

SUBSTANCE: invention refers to gas supply via main gas line and can be used when constructing main gas lines after hydraulic pressure tests are completed in order to dry them. Method is differed by the fact that in order to increase drying effectiveness, first, gas line is vacuumised till the specified pressure is reached, and is divided with cutoff valves into sections independent of each other. The first section is filled up with nitrogen-based inert gas, thus forming receiver; drying of the next gas line section after receiver and being under pressure is performed from receiver with nitrogen-based inert gas till specified values of humidity, pressure and concentration of nitrogen are obtained, and receiver is supplied with recirculating nitrogen obtained by separation of inert gas saturated with water vapours into nitrogen, oxygen, water and removal of oxygen and water from polymeric hollow fibre membranes. At that, inert gas saturated with water vapours to membrane is removed from the gas line section after receiver. Drying is stopped after specified values of humidity, pressure and concentration of nitrogen are obtained in the whole volume of the cavity of dried gas line.

EFFECT: invention must increase drying effectiveness of gas line cavity after hydraulic pressure tests are completed.

3 cl, 1 dwg