Engineering Bulletin

Cleaning can easily be performed by following the steps listed
below:
1. Loosen and remove the fastener(s) securing the cover to
the interceptor body.
2. Remove the cover.
3. Remove the flow diffusing baffle and/or sediment tray
assembly from the body.
4. Wipe down the baffle assembly, disposing of grease in a
proper waste container.
5. Clean out any liquid grease by skimming it from the top
surface. Remove any remaining solid material with a spade
or shovel.
GENERAL PRODUCT INFORMATION
Typical Zurn Grease Interceptor
In a Zurn Grease Interceptor, the static water level is at the
bottom of the outlet. Any piping into the interceptor below this
elevation will remain filled with water.
Odor from accumulated grease in an interceptor may pass
back through the piping system and through the drain opening.
An additional trap should be considered between the fixture
and interceptor. Consult local codes.
All Zurn Interceptors are 100% steel construction, coated with
a white acid resisting epoxy (A.R.C.). Z1170 Series Interceptors
are certified by the Plumbing and Drainage Institute (PDI).
Zurn Grease Interceptors are listed by the International
Association of Plumbing and Mechanical Officials (IAPMO).
Variables Affecting Grease Interceptor Performance
1. Velocity of Incoming Water
A higher velocity of water will contribute to a more turbulent
mixture. This will slow the grease separation process,
thereby reducing efficiency.
Recommended Solution – Install additional flow control
fittings at all sources of flow.
2. Ratio of Grease to the Water
The higher the ratio of grease particles to the water, the
lower the efficiency of the interceptor.
Recommended Solution – Increase the size of the interceptor.
3. Specific Gravity (Weight) of the Filtrates
Grease has a lower specific gravity than water and will
rise to the surface quickly. Grease-ladened food particles
having a higher specific gravity than water will linger and
accumulate at the bottom, eventually passing out of the
interceptor.
Recommended Solution – Install a solids interceptor at the
source of solid particles, prior to the grease interceptor.
4. Possible Presence of Detergents in the System
Grease-cutting detergents will break the liquid grease
into minute particles that can cause these liquids to
pass through the interceptor.
Recommended Solution – Increase the size of the
interceptor.
5. Percentage of Maximum Flow Capacity
If the maximum recommended flow is exceeded, the
efficiency of the interceptor will decrease considerably.
Recommended Solution – Install additional flow control
fittings at all sources of flow.
6. Location of Grease Interceptor
The interceptor should be located as close as possible to
the source of grease. Waste pipes leading to the grease
interceptor may become clogged if liquid cools prior to
entering the grease interceptor.
6. Remove the clean-out plug on the outlet portion of the body.
Using a clean water supply, hose down and wipe the inside
of the body.
7. Replace the cleaned baffle assembly back into the unit.
8. Ensure that the cover gasket material is intact and in good
working condition. Replace gasket material if it is damaged.
9. Securely refasten the cover and the clean-out plug back
onto the trap.
MAINTENANCE, continued
Old Style
New Style
Page 2