Choosing the best grease interceptor for a 3-compartment sink means matching the unit’s flow rate and grease capacity to your kitchen’s workload, then making sure it fits beneath the counter and connects to your plumbing. The options below are under-sink models with three-compartment separation designs. Their listed capacities, included parts, and maintenance features differ, so check the product dimensions and confirm local plumbing requirements before you buy.
Quick Comparison
| Product | Listed flow rate | Listed capacity | Standout feature | Best suited for |
|---|---|---|---|---|
| Commercial Grease Trap, 50 lb, 20.32 GPM | 20.32 GPM | 50 lb | Heavy-duty 1.8 mm carbon steel body | Kitchens seeking the highest stated capacity and flow in this group |
| Commercial Grease Trap, 40 lb, 15.32 GPM | 15.32 GPM | 40 lb | Removable filter basket and included hoses | Busy kitchens that want a more complete installation kit |
| Commercial Grease Trap, 40 lb, 15.32 GPM with Valves | 15.32 GPM | 40 lb | Heat rating below 80°C and tool-free basket access | Kitchens handling hot dishwashing or pot-sink wastewater |
| Commercial Three-Compartment Grease Trap with Hoses | Not specified | 40 lb stated in description | Top handle, lift-out basket, and quarter-turn valves | Buyers who value convenient access for routine upkeep |
| 40 lb Under-Sink Grease Trap with Filter Basket | 15.32 GPM | 40 lb | Included inlet and drain hoses | Those seeking a 40 lb unit with stated flow and connection parts |
Our Picks: Best Grease Interceptor For 3 Compartment Sink reviews
1. Best Higher-Capacity Option: 50 lb Commercial Grease Trap
This under-sink interceptor has the highest stated capacity and flow rate among the products in this roundup: 50 lb and 20.32 GPM. Its three-compartment design is intended to separate grease and solids from wastewater before it continues into the drain system. A 1.8 mm carbon steel body is listed as part of its heavy-duty construction.
The unit measures 20 x 20 x 28 inches, so check your available space carefully before ordering. Its threaded inlet and outlet, sealed lid, and locking buckles are designed to support a secure connection. The product is described as pre-assembled, with removable baffles and a smooth interior for maintenance.
The greater capacity may suit a kitchen with heavier sink use, but it does not automatically make this the right choice for every 3-compartment sink. Confirm that the stated flow rate fits your sink and plumbing plan, and ask a qualified installer about local requirements. Its listed dimensions may also make it harder to fit beneath some counters than the smaller-footprint options.
Pros:
- Highest stated capacity and flow rate in this group
- Three-compartment design with removable baffles
- 1.8 mm carbon steel construction
- Pre-assembled, with threaded ports and a sealed lid
Cons:
- Its 20 x 20 x 28-inch size needs careful space planning
- Confirm the installation and sizing requirements for your location before buying
Verdict: Consider this model if you need its higher stated capacity and flow rate and have enough room for its larger dimensions.
2. Best 40 lb Kit with Filter Basket and Hoses
This 40 lb under-sink interceptor is rated for a flow of up to 15.32 GPM. Its three-compartment layout is intended to help separate grease and solids as wastewater passes through. The listed construction includes a 1.8 mm, three-layer carbon steel structure with an inner rust-proof layer and an outer anti-corrosion coating.
For upkeep, the unit has a removable filter basket with a handle and a dedicated oil-draining port. Threaded joints with rubber sealing rings and a close-fitting cover are intended to help limit leaks. The package description includes an inlet hose, drain hose, and spare parts, which may simplify planning, though you should check that the supplied connections match your plumbing.
Its listed dimensions are 65.5 x 46 x 46 cm, and its stated unit weight is 22.4 kg. Measure the cabinet opening as well as the space inside it; hoses and access for opening the lid also need room. Compared with the 50 lb option, this model has a lower stated capacity and flow rate, but the removable basket and included hoses make it a practical middle-ground choice.
Pros:
- Stated 15.32 GPM flow rate and 40 lb capacity
- Removable filter basket and dedicated oil port
- Includes inlet and drain hoses plus spare parts
- Three-layer carbon steel construction is specified
Cons:
- Its dimensions and 22.4 kg weight require a suitable installation space
- Check hose length and connection compatibility before installation
Verdict: Choose this model if its 40 lb capacity and 15.32 GPM rating fit your needs and you want a basket and hoses included.
3. Best 40 lb Option for Hotter Wastewater
This three-compartment, 40 lb interceptor has a stated flow rate of 15.32 GPM. Its description specifies that it is designed for wastewater below 80°C, a useful detail for kitchens where hot dishwashing or pot-sink water enters the system. The 1.8 mm triple-layer body and vertical baffles are intended to manage the wastewater flow through the unit.
A lift-out inlet basket can be removed for emptying without tools, and the product description also lists dual filter tubes. Threaded ports, rubber rings, and PVC ball valves are included, along with a spare valve, inlet hose, and drain hose. These features may make routine cleaning and maintenance more straightforward, but access to the lid and basket still needs to be planned into the installation.
The listed footprint is 65.5 x 46 cm, and the unit is described as weighing 22.4 kg. Check the full installation dimensions and allow enough room for the hoses and valve access. Compared with the previous 40 lb model, this option stands out for its stated wastewater temperature limit and included valves; both have the same stated flow and capacity.
Pros:
- Specifies suitability for wastewater below 80°C
- 40 lb capacity and 15.32 GPM stated flow rate
- Lift-out basket, dual filter tubes, and vertical baffles
- Includes valves, a spare valve, and hoses
Cons:
- The temperature limit should be checked against your actual wastewater conditions
- Its size and weight call for a planned, accessible installation spot
Verdict: This is a sensible option if you need a 40 lb interceptor and the stated below-80°C wastewater rating suits your kitchen setup.
4. Best for Convenient Lid and Valve Access
This under-sink, three-compartment carbon steel interceptor is described as a 40 lb model. Its listed maintenance features are practical: a lift-out filter basket for catching larger solids, a top handle for opening the lid, and quarter-turn PVC ball valves for shutting off flow during maintenance.
The description also notes a rust-proof inner layer, smooth inner surfaces, and replaceable rubber sealing rings. These design details focus on making cleaning and seal checks easier. Hoses are mentioned in the product title, but the supplied description does not state a flow rate or provide the hose lengths, so confirm those details on the product listing before you plan the installation.
This option is most appealing if easy access for regular upkeep matters more to you than having a published flow-rate figure in the product details. Its listed size is 65.5 cm, but the supplied description does not give a complete set of dimensions. Verify the full measurements and make sure the lid can be opened where you plan to place it. Unlike the other 40 lb choices here, its supplied information focuses more on access and maintenance than on flow specifications.
Pros:
- Lift-out basket makes solids easier to remove
- Top handle is designed for easier lid access
- Quarter-turn valves support shutoff during maintenance
- Rubber sealing rings are described as replaceable
Cons:
- No flow rate is specified in the supplied product description
- Confirm full dimensions and hose details before ordering
Verdict: Consider this model if straightforward access and maintenance features are priorities, but verify its flow rating and complete dimensions first.
5. Best 40 lb Choice with a Compact Listed Footprint
This three-compartment interceptor is listed with a 40 lb capacity and a flow rate of up to 15.32 GPM. Its 1.8 mm, three-layer carbon steel construction is described as having an inner rust-proof layer and an anti-corrosion outer coating. The stated dimensions are 25.8 x 18 x 18 inches, giving you a clear starting point for checking whether it will fit beneath your sink.
The model includes a removable filter basket with a handle, a dedicated oil port, threaded joints with rubber sealing rings, and red butterfly valves. Its listed package also includes a 22.5-inch inlet hose, a 30-inch drain hose, and spare parts. Because hose routing and connection types vary by installation, check that these parts will work with your sink and plumbing layout.
The listed footprint is more compact than the 50 lb model, but this unit still weighs 22.4 kg, so plan how it will be positioned and accessed. It has the same stated capacity and flow rate as the other 40 lb options with flow information. The choice between them may come down to dimensions, the included fittings, and which maintenance features best match your kitchen routine.
Pros:
- 40 lb capacity and 15.32 GPM stated flow rate
- Listed dimensions make space planning easier
- Includes a removable basket, oil port, valves, and hoses
- 1.8 mm, three-layer carbon steel construction is specified
Cons:
- At 22.4 kg, it is not a lightweight unit to position
- Check included hose lengths against your plumbing layout
Verdict: Pick this model if its stated dimensions fit your cabinet and you want a 40 lb, 15.32 GPM unit with hoses and a removable filter basket.
How to Choose a Grease Interceptor for a 3-Compartment Sink
Match the Flow Rating to Your Sink
Flow rate is a key number to compare because the interceptor must handle wastewater from your sink setup. These products list flow rates from 15.32 to 20.32 GPM, while one listing does not provide a flow figure in its supplied description. Do not choose by capacity alone: ask your plumber or local authority what rating your sink and installation require.
Choose Capacity for Your Kitchen’s Workload
The options here list capacities of 40 lb or 50 lb. A higher stated capacity may be worth considering for heavier use, but the right size depends on how your sink is used and the sizing rules that apply where you operate. Confirm the required capacity before ordering rather than assuming that a larger unit is automatically suitable.
Measure the Installation Space
Measure the full under-counter area, including the opening needed to move the interceptor into place. Also allow room to open the lid, lift out the basket or baffles, reach the valves, and route the hoses. Compare those measurements with the product’s complete dimensions, not just its width or a single measurement in the title.
Check Connections and Included Parts
Look at the inlet and outlet type, hose lengths, valve design, and any included fittings. Some models list threaded connections and sealing rings; others include hoses, valves, or spare parts. These additions do not guarantee a direct fit with your plumbing, so confirm compatibility with your installer before you rely on them.
Plan for Regular Cleaning
Grease interceptors need routine maintenance. Removable baskets can make it easier to clear larger solids, while accessible lids and valves can help with inspection and cleaning. Choose a unit that staff can reach safely and maintain on the schedule required for your kitchen and local rules.
Check Temperature and Local Requirements
One model specifies wastewater below 80°C; the other supplied descriptions do not give a matching temperature limit. Compare any stated limit with the water entering the interceptor. Also check local plumbing codes and any site-specific requirements before purchasing, since product details alone cannot confirm that a unit is approved for your installation.
Frequently Asked Questions
Can these models be used with a 3-compartment sink?
They are described as under-sink, three-compartment grease interceptors. Whether a specific model is suitable for your sink depends on its flow needs, plumbing connections, available space, and local requirements. Confirm those details with a qualified installer.
What does GPM mean when comparing grease interceptors?
GPM means gallons per minute and describes the listed flow rate. Compare that figure with the requirement for your sink and plumbing setup. If a product description does not provide a flow rate, check the listing or ask the seller before buying.
Is a 50 lb interceptor always better than a 40 lb model?
No. A larger stated capacity may suit some kitchens, but the correct choice also depends on required flow, available space, and applicable sizing rules. Choose a unit that matches the installation rather than selecting capacity alone.
How much space should I leave around an under-sink unit?
Allow room for the interceptor’s full dimensions, its connections and hoses, and access to the lid, basket, and valves. The required clearance depends on the exact installation, so have the installer check the cabinet and service access before the unit is placed.
Do these interceptors need routine cleaning?
Yes. The product descriptions include baskets, baffles, or oil ports intended to support maintenance. Follow the manufacturer’s instructions and the maintenance schedule required for your kitchen and local rules.
Are the included hoses guaranteed to fit my sink?
No. Hose lengths and connection details vary, and compatibility depends on your plumbing layout. Check the supplied measurements and fittings, then confirm the connection plan before installation.
Final Recommendation
For the highest stated flow rate and capacity in this group, the 50 lb model is the standout, provided its larger dimensions fit your space and its ratings meet your installation requirements. For a 40 lb option with a stated 15.32 GPM flow rate and included hoses, the second and fifth models offer useful maintenance features to compare. Before choosing any interceptor, verify the full dimensions, connection details, and local sizing requirements with a qualified installer.