Tips for Choosing Right Size Commercial Kitchen Grease Trap

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Tips for Choosing Right Size Commercial Kitchen Grease Trap

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A grease trap’s size should be determined based on the type of commercial kitchen and the type of restaurant. Overflows, backups, and unnecessary costs can be prevented. Grease trap sizes aren’t easily determinable, especially since each commercial kitchen is different. Additionally, most plumbing codes ignore peak flow when sizing, indicating more capacity than required. Similarly, these codes assume that most kitchen fixtures are constantly experiencing peak flows. 

To determine the right grease trap size for a commercial kitchen, how do you calculate the volume of the grease? Relax! The following guide provides grease trap sizing guidelines that will keep your establishment’s septic system functioning at its best.

What is a Grease Trap?

Grease traps are a device used to collect grease, and they are normally installed underneath kitchen sinks so grease can be collected.

As soon as oil or fat is poured down the drain, it funnels into the grease trap container to be disposed of. It is a device that slows down the flow of water, which allows the grease to be stored safely as it slows down the flow of water.

As part of the grease trap equipment, Grease trap cleaning Lehigh Acres of used oil may be a better choice for restaurants that serve fried foods often.

Factors that Determine Grease Trap Sizing

Grease tarp size depends on how much water flows down drains (incoming flow rate). However, your food service establishment’s grease trap size will depend on other factors. There are several factors to consider, including: 

  • Commercial kitchens have a certain number of sinks and fixtures
  • Food served at the event
  • The size and type of the restaurant
  • Regulations of local authorities

How to choose the Right Size Grease Trap

1. Solo Use Or Shared Grease Trap

Another consideration is whether your establishment will use the grease trap alone or share it with adjacent businesses. Sometimes, especially in shopping centers and malls, a group of businesses will share a grease trap system with a capacity of 5000 or 6000 liters.

The grease trap’s size would be based on the type and number of businesses using it together. However, grease trap experts have formulas for such situations, and it is part of their job to determine the right size for your system when installed.

2. Local Authority Codes And Regulations 

Local authority codes should be consulted when calculating grease trap size for restaurants. A code determines what should be installed and designed. The Plumbing and Drainage Institute already set codes that they usually follow.

A dishwasher may not be attached to a grease trap in most cases, depending on the municipal code. In this way, wastewater is directly discharged into sanitary sewers. The grease traps must, however, be connected to all drains according to some codes. 

Commercial grease traps can also be designed and installed according to local plumbing codes. Moreover, these codes may require plumbers and engineers to estimate the trap’s size in two ways. There are two factors to consider: gravity flow rates and fixture capacities. IAPMO (International Association of Plumbing and Mechanical Officials) established the UPC (Uniform Plumbing Code), which guides both options. 

3. Grease Trap Sizing Using Fixture Capacity

When you know the dimensions of your fixtures, you can use the fixture capacity approach. The gravity flow rate method will be the best option if the fixture dimension is unknown. 

As previously mentioned, a grease trap’s flow rate determines its rating. By measuring the volume of fixtures draining into it, you can estimate its size. 

Flow rates are calculated by determining the capacity of fixtures draining into the trap. To calculate the volume of the fixture, measure its width, depth, and length in inches. Considering that 1 gallon equals 231 cubic inches, convert this figure into gallons. 

Calculate the loading factor (fill factor). A loading factor measures how much water can be drained from a fixture into a grease trap. For example, if the sink is typically filled to 75%, the loading factor is 0.75. To determine the fixture capacity, multiply the loading factor by 7. 

Obtain the time it takes for fixtures and sinks to drain wastewater into the grease trap designed for the restaurant for proper grease trap cleaning in Florida. Minute drainage periods are typically between 1 and 2 minutes long. You should divide the previous step’s result by one or two minutes. Gallons per minute will be the flow rate.

4. Grease Trap Sizing Using Gravity Flow Rates

According to this method, the size of the grease waste pipe is determined according to the diameter of the pipe. The maximum flow rate allowed for a waste pipe with a diameter of 20 inches or larger is 20 gallons per minute (GPM), according to the Uniform Plumbing Code.

A grease trap rated at 10 gallons per minute (GPM) will be required if you choose a two-minute drainage period for the grease. The specific requirement is that, in this particular case, you must ensure that the volume of the sink that feeds into the grease trap, rated at 10 gallons per minute GPM, does not exceed 25 gallons.


When choosing a grease trap, it is important to consider your restaurant’s needs and flow. Ultimately, any grease trap needs to be properly maintained to work efficiently. Professional cleaning services will ensure that the invention will save money on plumbing repairs.

The team at Crews Environmental specializes in maintaining, Grease Trap Cleaning, and repurposing the oil. Get in touch with us today to find out how we can help you prevent waste oil from going to waste and maintain your grease trap.