What is the main concern for the shutdown valve design in pipeline installation?
Pipeline is usually required to be cleaned periodically using pigging system. Pigging system consist of pig launcher, pig receiver and a pig. Pig has brush part which can tear out soft material.
Metal material is required to avoid broken seat due to pigging. Therefore, the design of pipeline shutdown valve shall specify metal seat.
Another requirement is that ball valve type Shutdown Valve (SDV) in pipeline shall be full bore.