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 a   rrangement 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 9001:2015 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 as part of updated Brochure. It can be downloaded at this link:

BMS Petrol Oil Interceptor Brochure and Selection Charts

A Load of Bypass Interceptors leaving the BMS Factory

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A bit about the company

BMS is a quality manufacturer of package products for wastewater and stormwater treatment. BMS started in 1986 and has exported products to over 50 countries around the world.  It is a third-generation family business with huge expertise in wastewater and stormwater.

BMS also manufacture a full range of products for surface water and wastewater treatment including our pioneering next generation RBC system the Aerotor, which forms part of our world-leading Blivet package sewage treatment plant, a ‘one stop shop’ for all surface water products from design to installation including;

• attenuation,

• interceptors,

• holding tanks (incl. chemical resistant),

• hydrobrakes,

• rainwater harvesting tanks & vortex silt/oil/debris separators,

• fully fitted pumping stations,

• our plug & play vehicle wash water recycling system; the Recyclone

• and much more. 

Please see our enclosed Company & Product Profile for a full summary or View our full product/services catalogue at this link

BMS also provides:

• Free Design Service for Sewage Treatment, Pump Stations, and Surface Water Treatment

• Full Operation and Maintenance, Repair, Advice, and Testing services for existing installations.

We also can do free CPD Presentations on Sewage Treatment/Surface Water Management at any location. 

We would be delighted to discuss any requirements you might have, and we are available to meet you at your convenience.  Contact us today.