Pig Stopper

A pig stopper is pneumatically actuated to position a rod across the housing to prevent movement of the pig. The pig stopper has two functions dependent on the system design:

• If the catching pipe (see illustration on right) is used as a pig launching station then the pig stopper prevents the pig from moving from the catching pipe under vacuum. See diagram EMII/1.
• Pig stoppers allow the positioning of pigs before and after Tee pieces.