What are the different types of Petrol/Oil Interceptor (Separator) and what is the difference between them?

Following on from last week’s question on the difference between a Petrol/Oil Interceptor & a Separator, another customer asked; What are the different types of Petrol/Oil Interceptor (Separator) and what is the difference between them?

There are 2 main types of Petrol/Oil Interceptor;

Full Retention Interceptors, which are designed to treat the full flow delivered by a drainage system up to 50 mm/hr.

Bypass Interceptors which, are designed to treat flows of up to 5 mm/hr.  This covers 99% of rainfall.

A Full Retention Interceptor is normally used when there is a risk of regular contamination of surface water run off with petrol/oil and/or the risk of larger spills e.g. vehicle maintenance areas, heavy goods parking areas or where frequent vehicle manoeuvring takes place.

A Bypass Interceptor is normally used when there is a risk of infrequent light contamination of surface water run off with petrol/oil and/or the risk of only small spills e.g. car parks, airports, industrial estates, roads and other low risk areas.          

Under normal flow conditions the BMS Full Retention Interceptor is designed to retain the full contents of an oil spill or contamination up to flows of 50 mm/hr.  For flows under 5 mm/hr a bypass interceptor functions in the same way.  In the case of storm water flows above 5 mm/hr an internal vortex arrangement allows the stormflows to bypass the retention chamber, this has the benefit of considerably reducing the size of the interceptor required while still treating 99% of rainfall.  The majority of pollutants in any storm water event will be trapped before the bypass takes place.

BMS manufacture produce a full range of 'plug & play' interceptors/separators from 1,000 - 100,000 litres manufactured in corrosion and rot proof GRP under ISO 9001:2008 to European Standards and are Irelands leading producer.

BMS have introduced a full set of Petrol Interceptor/Holding Tank Sizing & Selection Charts to help you easily size and select an Interceptor/Holding Tank suitable for your requirements. They can be downloaded at this link.

If you have any other questions or queries please contact us.