On ships, an oily water separator (OWS) is a crucial piece of equipment used to remove oil from bilge water before it’s discharged overboard, ensuring compliance with environmental regulations and preventing pollution.

• Purpose:

OWS systems are designed to separate oil from oily waste water, such as bilge water, which may contain oil from leaks or spills.

• Regulatory Requirement:

The installation of OWS is a regulatory requirement, as outlined in MARPOL Annex I, Regulation 14, for ships above 400 GT.

• How it Works:

OWS systems typically use a combination of gravity, coalescing, and filtration to separate oil from water.

• Oil Content Monitoring:

An oil content monitor continuously measures the oil content of the effluent, and if the limit (typically 15 ppm) is exceeded, the effluent is automatically recirculated to the collecting tank, or the separator is stopped.

• Types of OWS:
  • Centrifugal OWS :These use centrifugal force to separate oil from water.
  • Other types :Some OWS systems utilize dissolved air flotation and flocculation.
• Importance:

By effectively separating oil from water, OWS systems help protect the marine environment from pollution and ensure compliance with international regulations.