Working Pressure

The working pressure capability of a coupling varies with its size and construction. It is also dependent upon correct pipe tolerances and surface finish.  Wider pipe OD tolerances than those specified will result in a reduction in pressure capability. For most pipe materials, the actual test pressure will be lower than that of the coupling and will be determined by the pipe capability or class.  Similarly the pressure rating of a flange adaptor will be determined by the rating of the main flange (eg. PN16 = 16 bar working pressure, 24 bar test).

When assembled onto the pipe(s), the pressure rating of the completed assembly will be that of the lowest rated component. Under normal circumstances working pressures are up to 2/3 of the maximum test pressure shown in any Viking Johnson literature appropriate schedule.