Check List for Layout of Pig Launching and Receiving Stations (Pig Trap or Scraper Trap Stations)

Sr.No Check Description
1 Launchers and Receivers
1.1 Grouped together close to the fence and lined up along the primary road to allow easy maintenance.
1.2 Provided with adequate lifting facilities or mobile equipment for maintenance.
1.3 Access provided for pig handling trolleys, mobile lifting cranes or trucks to safely handle, load and unload the pig from two sides.
1.4 End Closures  are oriented away from personnel, hydrocarbon containing equipment, main accessways, traffic path or safety critical equipment (This is to prevent accidental release of a pig projectile from the end closure causing harm to personnel and damage to equipments).
1.5 Pigging requirements such as sphere, foam pigs, intelligent tools are considered. (Note that Intelligent Pigging may require the pig trap length to be longer and hence requires more space).
1.6 Bi-directional pigging requirements are considered if applicable.
1.7 Space requirements for riser bends, barred tees are considered.
1.8 All hinges of the end closure doors are oriented on the same side and the hinge location and the door swing volumes are modelled/shown in the layouts.
1.9 Pig Trap supports are of sliding type.
1.10 Catch pit or tray is provided below the end closure with sufficient volume and surface area to prevent any oil or debris contamination of the surrounding ground.
1.11 Drainage system is provided to collect spills from the trap and wash water.
1.12 All major operating valves are accessible from one side of the trap where a platform may be provided if required.
1.13 Bottom of end closures are located approximately 700-1000mm above grade to allow enough room to route the pig trap drain lines and for ease of handling the end closure doors and pigs.
1.14 A minimum of one pig length of straight pipe run is provided upstream and downstream of all bends.
1.15 A minimum of one pig length of space plus operator space is provided behind the trap to facilitate the launching and
receiving operations.
1.16 Pig Traps are located at least 15 m away from equipments that could be a potential source of ignition.
1.17 Horizontal pig launchers are sloped towards the minor barrel  and pig receivers are sloped towards the end closure with a slope of 3-5 degrees. Bi-directional pig traps are not provided with any slope.
2 Manifolds and Flowline Battery Limit Valves
2.1 Flowline Battery Limit Valves and Pipeline Emergency Shutdown Valves are located close to the fence.
2.2 Manifolds are located at least 50m from Flowline Battery Limit Valves
2.3 Manifolds are provided with adequate lifting facilities
3 Pipeline Corridor
3.1 Incoming and departing pipelines are grouped together within a common corridor, with adequate clearance maintained between the pipelines and must not pose an obstacle for mobile equipment and personnel
4 Slug Catchers
4.1 Located close to Receivers to minimise possibility of slug flow.
5 Provision of Wind Sock
5.1 A windsock is installed at the pig trap stations to indicate wind direction in the event of a leak.