Grease traps work on the basis that animal fats and vegetable oils (grease) are 10 to 15 percent less dense than water and that grease won’t mix with water. Thus, fats and oils float on top of water.
When wastewater enters a grease trap, the flow rate is reduced enough so the wastewater is given enough time to cool and separate into 3 layers. The grease rises to the top inside the interceptor and is trapped using a system of baffles. Solids settle at the bottom and the separated clear water escapes under an outlet baffle. Many grease traps also have strainers for collecting solid debris, which reduces the amount of solids that settle at the bottom of the trap.
Over time solids and grease build-up, and if left to accumulate for long enough they can start to escape through the outlet and in some circumstances, they can back-up through the inlet. For this reason, the trap must be cleaned / pumped out on a regular basis.
The PRemier Tech range of GNS Grease Traps/Separators works through a simple two-chamber tank where wastewater enters the primary chamber and debris settles. The wastewater then flows into the gravity separation chamber where grease and oil rise to the surface.
A low-level pipe removes the separated water from the secondary chamber and releases it to the drainage system. The surface layer of grease will remain inside the tank until it is removed by a Waste Disposal company
Tank Code |
Capacity (litres) |
Diameter (mm) |
Length (mm) |
Flow (litres/second) |
Meals served per day |
GNS2 |
1250 |
1000 |
1718 |
1 (2 max.) |
100 meals |
GNS4 |
1750 |
1000 |
2330 |
2 (4 max.) |
200 meals |
GNS7 |
2600 |
1200 |
2427 |
4 (7 max.) |
400 meals |
GNS10 |
4300 |
1200 |
3957 |
5 (10 max.) |
500 meals |
GNS15 |
6000 |
1500 |
3645 |
8 (15 max.) |
800 meals |
GNS20 |
8500 |
1800 |
3640 |
10 (20 max.) |
1000 meals |
GNS25 |
11000 |
1800 |
4623 |
13 (25 max.) |
1300 meals |