What Is an Ejector Pump?

As a property owner, you understand the importance of maintaining a functional and habitable building. Still, you may not know the intricacies of every system or device that keeps operations running smoothly. Your property uses several pumps in everything from heating and cooling to hot water and cold water supplies and even waste management. In fact, one of the essential pumps in many NYC properties is the sewage ejector pump, but what is an ejector pump, and why is it so important?

What Is an Ejector Pump, and How Does It Work?

Purpose and Use

A sewage ejector pump is a straightforward centrifugal pump. Most modern designs are submersible and can move soft solid and liquid waste. The pump is not essential in every NYC building. It is mainly used in properties with laundry or bathroom facilities in their basements.

In a typical property, sewage and wastewater lines slant towards sewer mains. Gravity assists the waste in flowing from the building into the sewage lines, along with extra water supplies. The problem arises when pipework does not have enough of an angle or grade to use gravity or when plumbing is below grade, meaning waste lines must somehow move contents up to the mains. The sewage ejector system uses centrifugal force and horsepower to propel wastewater to an appropriate height, allowing gravity to work from there.

Types

As you learn about the uniqueness of an ejector pump, you must familiarize yourself with the three pump categories: submersible, self-priming, and vertical. Each pump offers unique benefits and use cases. Learning about each helps you determine which is best for your building.

The submersible pump is the most modern and common of the three ejector pump options. As the name implies, the pump is fully submersible; it is installed in a sump basin with single- or double-seals. Double seals offer more durability and might be better for apartment or multi-unit properties with more operational demands.

As a property owner, you may want to invest in a grinder ejector pump, which can break down solid waste without risking clogs or breakdowns. Grinder pumps can help septic and sewage systems run more efficiently.

A self-priming pump is less durable than a submersible option but better for small, tight spaces. The self-priming ejector option sits on top of the sump basin rather than inside and fills with water. Significant advantages of the self-priming over the submersible pump include easier cleaning and repair work. These pumps work best for shallow basins.

Finally, the vertical ejector pump is an ejector pump with a long operating life. It is the oldest model still in use and seems like a deconstructed ejector model. The pump motor rests on the plate outside the basin, and the pump shaft and discharge pipe are submersible. These pumps require frequent lubrication and are best for infrequent use.

Typical Operations

Sewage ejector pumps are not complex pieces of machinery. They comprise a two-piece arrangement: a pump and a float. With a submersible setup, the pump sits in the sump basin with a float attached. As the sewage level in the basin rises, the float lifts. Once the float reaches a certain height, it engages the pump motor. Then, the pump expels the waste, providing adequate pressure to lift the waste to the proper line and down the sewer pipe to the main septic line.

The float lowers to its usual resting location as the wastewater level recedes in the basin. Once back in its proper place, the pump disengages, turning off and ending the cycle.

Because the continuous cycles result in shifting pressure, a vent is necessary to equalize the system. The vent also helps release built-up sewer gasses, preventing odors from entering the living spaces. The vent pipe usually runs from the pump basin to an existing vent stack, which runs up the property to the roof.

Installation

An ejector pump installation typically occurs in a basement or sub-basement where plumbing and septic fixtures exist. For example, your building may have basement-level laundry facilities that require a wastewater ejector pump because the plumbing is below your sewer main. You may also need the pump installed if you renovate your property and install basement units or bathrooms.

Professionals should handle all installations. While the pump is not complicated to understand, the installation process is relatively complex. Installers need to:

– Assess the sewage basin location and seals
– Remove old pumps
– Inspect the existing pit
– Drill a weep hole
– Test the unit

Maintenance

Ideally, an ejector pump should last 7 to 10 years with minimal maintenance. The pump requires an annual inspection and service by a licensed plumber. During the service, the professional cleans the unit, performs a complete inspection, oils the motor, and assesses all components and connection points.

Building owners can help keep their systems running well by informing tenants of what can and can’t go down the drain. Flushing anything other than waste and toilet paper can clog the pump or overwork the motor. Not only can these issues shorten the lifespan of the pump, but they can also lead to unfortunate sewage backups.

What Is the Difference Between a Sewage Ejector Pump and a Sump Pump?

Wastewater Versus Groundwater

People often compare ejector pumps to sump pumps. While there are some similarities between the two devices, they perform entirely separate tasks. The expulsion of wastewater and waste is the only job of a sewage ejector pump. The primary purpose of sump pumps is to remove groundwater or rain runoff, not sewage.