Pipe systems used to transport water, typically returning to the cooling tower, to various units in the process units of large oil supply lines and chemical, petrochemical, and refinery-type facilities are particularly placed underground. The term “underground” encompasses both buried pipes and those placed in trenches. These underground systems include gravity flow drainage systems carrying process waste, leakage, reclaimable hydrocarbons, sanitation and rainwater, firewater, and drinking water systems.
The design of the underground pipeline system in the facility is determined by good engineering practices, local codes/regulations, and specific customer requirements.
Common underground services in chemical/petrochemical/refinery facilities include:
- Cooling water
- Firewater
- Contaminated Rainwater Sewer from the process catchment area
- Oily Water Sewer
- Liquid Effluent to the Effluent Treatment Plant
- Closed Blow Down system
- Sanitary system
- Stormwater
- Equipment drainage to the slop tank
- Electrical cables
- Instrument cables