A grease trap, also called a grease interceptor, catches fats, oils and grease before they enter the sewer. Most food service businesses need one, and local rules control its size and placement. This guide explains how grease traps work, how sizing is usually approached and what to ask before you buy.
Shop the equipment in this article: Carbon steel grease trap interceptor, S3C-141612-NF 47 x 22 three compartment sink and grease traps. Freight is included on every order.
How a Grease Trap Works
Wastewater from sinks flows into the trap. Inside, baffles slow the water down. Grease is lighter than water, so it floats to the top and stays in the tank. Solids sink. Cleaner water flows out to the sewer. Over time, grease builds up and must be removed. If it is not, it passes through and clogs pipes, causing backups and fines from the sewer authority.
Who Needs One
Restaurants, cafes, bakeries, bars that serve food and commissaries typically need a grease trap on fixtures that handle greasy water, such as three compartment sinks, pre-rinse sinks and floor sinks. Some areas also require them on dishwashers or mop sinks. Requirements vary a lot by city and county, so confirm with your local plumbing inspector, sewer authority or a licensed plumber before buying.
Sizing Basics
Grease traps are rated by flow rate in gallons per minute and by grease holding capacity in pounds. A common approach is to calculate the volume of the sinks connected, then estimate how fast they drain. For example, a larger three compartment sink holds a lot of water, and draining all three bowls at once creates a high flow. Your plumber will run the numbers for your fixtures. Pick a trap whose flow rating meets or exceeds that calculation.
GT-40-LO 40 lb low profile steel grease trap interceptor, 20 GPM
GT-70-LO 70 lb low profile steel grease trap, 35 GPM, 3 inch inlet and outlet
Carbon steel grease trap interceptor
Installation Location
Under-sink traps sit on the floor next to or below the sink. Low profile traps help where space under a sink is tight. Some jurisdictions require in-ground interceptors outside the building for larger operations. Leave room to open the lid and pump the trap. A trap you cannot reach does not get cleaned.
Flow Control
Many installations include a flow control device on the inlet so water does not rush through faster than the trap is rated. Ask your plumber whether one is needed.
Cleaning and Maintenance
Small traps may need cleaning weekly or even more often in busy kitchens. Keep a log of each cleaning. Scrape plates into the trash before washing so food solids stay out. Never pour fryer oil down a drain. Store used oil in a proper container for pickup.
Questions to Ask Before You Buy
- Which fixtures will drain into the trap?
- What flow rate did my plumber calculate?
- Does my city require an under-sink trap or an in-ground interceptor?
- How much space do I have under or near the sink?
- Who will clean it, and how often?
- Do I need a flow control device?
Connecting to Your Sinks
The trap is only as good as the sink setup. Plan your three compartment sink and pre-rinse station with the trap in mind.
S3C-141612-NF 47 x 22 three compartment sink
Next Steps
Browse grease traps and 3 compartment sinks, then have your plumber confirm the size. Questions? Contact Express KitchQuip and we will help you pick the right size and configuration.
Models in this guide at a glance
The models linked above are listed here with the main points from each product page, so you can compare them side by side before opening the full listings.
GT-40-LO 40 LBS Low Profile Steel Grease Trap Interceptor (model GT-40-LO)
- Brand: Express KitchQuip
- Protect your municipal sewer system and drainage facilities from the damaging effects of fat, oil, and grease with this durable grease interceptor.
GT-70-LO 70 lb Low Profile Steel Grease Trap – 35 GPM (model GT-70-LO)
- Brand: Express KitchQuip
- This 70 lb Low Profile Steel Grease Trap is engineered to handle tough, high-volume commercial kitchen environments.
- Designed with a 35 GPM flow rate, it efficiently separates grease, fats, and oils from wastewater before they reach your plumbing.
Express KitchQuip Carbon Steel Grease Trap Interceptor – NSF Certified, Under Sink (model EKQ-GT-CARBON)
- Brand: Express KitchQuip
- NSF certified carbon steel grease trap interceptor for commercial kitchens, available in 8, 14, 20, 30 and 40 lb grease capacities.
- 11-gauge carbon steel with corrosion-resistant coating, no-hub connections, removable baffles, T-vent and non-skid deck plate included.
- PDI certified.
S3C-141612-NF 47″ x 22″ Three Compartment Stainless Steel (model S3C-141612-NF)
- Brand: Express KitchQuip
- 47″ x 22″ three compartment stainless steel sink designed for compact commercial kitchens.
- Features (3) 14″ x 16″ x 12″ bowls, durable stainless steel construction, and NSF certification for professional foodservice use.
Before you order
- Measure the space and every doorway on the delivery path, and compare them with the dimensions on each product page.
- Check the spec sheet for power, gas or water requirements and match them to what your building has.
- Compare capacity with your busiest day rather than your average day.
- Read the warranty terms for the brand before you order.
Delivery, warranty and payment
- Delivery: delivery within the continental US is included in the price on the product page, and freight orders include liftgate service.
- Warranty: each product carries its manufacturer warranty. Terms by brand are on our warranty page.
- Financing: lease-to-own financing through Clicklease is offered on items of $500 and up. See how financing works.
- Quotes: buying for a business and need a written quote? Call +1-877-558-2253 or use our contact page.
Not sure which model fits?
Call +1-877-558-2253 with your space, power supply and daily volume, and we will help you narrow it down.