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. | |