A dedicated Pig Receiver has a minor barrel length which can accommodate the full length of a pig so that once a signaller, that is located close to the reducer, detects the front end of the pig, the back end will have cleared the main isolation valve and allow this to be closed. The major barrel is normally as long as the minor barrel. Where spheres are received, it is often common practice to incline the barrels towards the closure to facilitate their removal from the barrel.