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External & Underground Grease Separators

External & Underground Grease Separators

Hydromechanical Grease Separation

Hydromechanical Grease Separators separate Fat, Oil and Grease (FOG) from greasy water which typically results from the preparation and service of food.  The term Hydromechanical Grease Trap means a design that incorporates air entrainment, hydromechanical separation, interior baffling, or barriers in combination or separately.

In the past concrete was commonly used in the manufacture of grease traps but the presence of acids in greasy waste resulted in corrosion and breakdown of the unit within as little as 10 years.

MACTRAP manufactures grease separators from High Density Polyethylene (HDPE) which remains totally unaffected by greasy water acidity allowing us to provide a 30 year warranty with all inground units – a strong financial motivation for building owners.

The benefits of MACTRAP grease separators start at installation. Because they are lightweight and easy to transport and maneuver they require less machinery and time to install saving up to 50% of upfront costs. If your application requires a custom size or configuration we can typically design and build to meet those requirements within four weeks.

MACTRAP manufactures products to support New Zealand’s environmental goals and all of our products comply with the NZBC G13.

Polymer grease separator systems are a superior alternative to concrete grease traps as they do not need to be refurbished, even after many years.


Only New Zealand grease separator with an inground 30 year warranty against leak tightness and structural integrity.

HDPE polymer is lightweight and manoeuvrable saving up to 50% of installation costs.

Above and below ground options with vehicular and pedestrian risers and covers

Welded frame with 12mm wall thickness for robustness and reliability

Increased baffles and chambers for greater efficiency

Flexible couplings for earthquake protection

Handles harsh chemicals, heavy FOG, and temperatures up to 65°C

The polyethylene material used is resistant to aggressive fatty acids – and therefore particularly durable. We provide a 30-year warranty for leak tightness, fitness for purpose and structural safety of tanks and upper sections.


S = Above Ground Standard
A = Below Ground Pedestrian
D = Below Ground Vehicular
Treatment Capacity
MTPT250 (S) (A) (D) 250 1200 520 627
MTPT500 (S) (A) (D) 505 1200 645 880
MTPT750 (S) (A) (D) 779 1200 806 1050
MTPT1000 (S) (A) (D) 1038 1600 806 1050
MTPT1500 (S)* (A) (D) 1557 2400 806 1050
MTPT2000 (S)* (A) (D) 2014 2410 844 1210
MTPT2500 (S)* (A) (D) 2506 2410 1040 1210
MTPT3000 (S)* (A) (D) 3013 3000 794 1510
MTPT4000 (S)* (A) (D) 4110 3000 1000 1610
MTPT5000 (S)* (A) (D) 5100 3000 1250 1610
MTPT6000 (S)* (A) (D) 6018 3000 1475 1610

* Above ground separators from 1500L to 6000L are shipped with metal cages to prevent heat distortion.

** If required, the cages can be constructed for seismic restraint. Contact Mactrap for more information.


MTPT250 Data Sheet
MTPT500 Data Sheet
MTPT750 Data Sheet
MTPT1000 Data Sheet
MTPT1500 Data Sheet
MTPT2000 Data Sheet
MTPT2500 Data Sheet
MTPT3000 Data Sheet
MTPT6000 Data Sheet
GT Installation Cover Web

Covers and Risers

Mactrap separators are available with Class A Pedestrian lids in HDPE and Class D Vehicular lids in cast iron. The riser mounts are pre-welded and a flexible coupling allows easy installation of the fully sealed riser flanges and screw on covers. Surrounding concrete or other medium must be engineered for the appropriate loading.

Further Information

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Greasy Lift Pump

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