How Does A Commercial Toilet Flush Valve Work? A Comprehensive Guide

If you’ve ever used a public restroom, chances are you’ve encountered a commercial toilet with a flushometer-valve system. But have you ever wondered how it actually works?

In this article, we’ll take a closer look at the inner workings of a commercial toilet flush valve and explore the technology that makes it all possible.

From the basic components to the latest advancements, we’ll cover everything you need to know about this essential piece of plumbing equipment.

So, let’s dive in and discover how a commercial toilet flush valve really works!

How Does A Commercial Toilet Flush Valve Work

A commercial toilet flush valve is a crucial component of any public restroom. Unlike traditional gravity-powered tank-type toilets, flushometer-valve toilets use water pressure from the water supply system to flush waste away.

The flush valve itself is located in the center of the cistern tank and is typically made of plastic or brass. It is operated by a rubber or neoprene flapper, or a ‘float ball’, which sits against the valve opening and keeps water in the cistern tank until the flush handle is operated.

When the user presses down on the handle, a chain or lift wire connected to the handle rod lifts the flapper away from the valve seat, allowing water to flow down out of the cistern and fill the toilet bowl. Once all of the water has left the tank, the flapper falls back down into the valve seat, sealing the opening and allowing water to refill the tank.

Integrated into the flush valve is a vertical overflow tube that extends from the base of the flush valve up into the tank. This overflow tube serves two purposes: it prevents water from overflowing the tank and allows small amounts of water to flow down into and fill the toilet bowl as the tank refills.

A small refill tube located at the top of the overflow tube allows a stream of water to flow down into the bowl during the refill cycle. This restores the level of standing water in the toilet bowl, keeping the trap sealed.

The Basics: Components Of A Flush Valve System

The flush valve system consists of several key components, including the flush valve, flapper, overflow tube, and refill tube.

The flush valve is the main component of the system, located in the center of the cistern tank. It is typically made of plastic or brass and is operated by a rubber or neoprene flapper or a ‘float ball’. The flapper sits against the valve opening and keeps water in the tank until the flush handle is operated.

When the user presses down on the handle, a chain or lift wire connected to the handle rod lifts the flapper away from the valve seat, allowing water to flow down out of the tank and into the toilet bowl. Once all of the water has left the tank, the flapper falls back down into the valve seat, sealing the opening and allowing water to refill the tank.

Integrated into the flush valve is a vertical overflow tube that extends from the base of the flush valve up into the tank. This overflow tube serves two purposes: it prevents water from overflowing the tank and allows small amounts of water to flow down into and fill the toilet bowl as the tank refills.

A small refill tube located at the top of the overflow tube allows a stream of water to flow down into the bowl during the refill cycle. This restores the level of standing water in the toilet bowl, keeping the trap sealed.

How Does Water Enter The System?

Water enters the commercial toilet system through the water supply line, which is connected to the flush valve. As soon as the user presses down on the handle, the flush valve opens, allowing water to flow from the cistern tank into the toilet bowl. The water pressure from the supply line is what powers the flush, and once the water has left the tank, the flapper closes off the valve seat, stopping the flow of water.

During the refill cycle, water enters the system through the refill tube located at the top of the overflow tube. This stream of water flows down into the bowl, restoring the level of standing water and keeping the trap sealed. The overflow tube also allows small amounts of water to flow down into and fill the bowl as needed.

It’s important to note that using clean and safe water is crucial for any commercial toilet system. Installing a water purifier or filtration system can ensure that the water entering the system is free from harmful microorganisms and additives that could interfere with its function. By maintaining a steady supply of clean water, a commercial toilet flush valve can work efficiently and effectively for years to come.

Understanding The Role Of The Diaphragm

The diaphragm is a crucial component of a flushometer valve. It is responsible for regulating the pressure within the flush valve and controlling the volume of the flush. When the flushometer handle is pulled or the sensor is activated, the diaphragm acts as a regulator, maintaining the necessary pressure within the unit to prevent water from flowing when it isn’t supposed to.

The diaphragm assembly is located directly below the inside cover in the top of a flush valve. It consists of a flexible rubber disk that separates the upper from the lower chambers in a diaphragm flushometer. The diaphragm assembly, along with other working parts like the vacuum breaker, needs to be replaced after about 250,000 flushes or approximately 4 years in high traffic facilities.

Signs that your drop-in kit needs to be replaced include a flushometer that no longer flushes, one that will not shut off, a flush that is too short or too long. The diaphragm and piston valves both include components and design characteristics that control the rate at which the valve opens and shuts, as well as the amount of water that flows to the fixture during this operation. This allows both valve technologies to accurately deliver a controlled amount of water to the fixture under a variable range of water pressures and flow rates.

Diaphragms are best used for medium to high traffic areas because they require higher water pressure and are designed for faster recovery after each flush. Understanding the role of the diaphragm in a commercial toilet flush valve is crucial for maintenance teams in order to recognize when replacement is needed and how to properly install it without damaging it. The ability to fine-tune a flush when needed ultimately results in water savings versus only being allowed to make major changes to the discharge that waste water.

The Mechanics Of The Flush: From Handle To Valve

The flush mechanism of a commercial toilet begins with the user pressing down on the flush handle. This handle is connected to a chain or lift wire that lifts the flapper away from the valve seat, allowing water to flow down into the toilet bowl. The flapper is a crucial component of the flush valve, and it is typically made of rubber or neoprene.

As the water flows out of the cistern tank and into the bowl, the flapper slowly sinks back down to seat on the flush valve. This closing off of the water to the bowl triggers the toilet fill valve, also known as a ballcock, to begin bringing water back into the cistern tank to recharge for the next flush.

The flush valve itself is located in the center of the cistern tank and can be made of either plastic or brass. It operates with a rubber or neoprene flapper or a float ball, which sits against the valve opening and keeps water in the cistern tank until the flush handle is operated.

Integrated into the flush valve is a vertical overflow tube that extends up into the tank from the base of the flush valve. This tube serves two purposes: it prevents water from overflowing the tank and allows small amounts of water to flow down into and fill the toilet bowl as the tank refills.

A small refill tube located at the top of the overflow tube allows a stream of water to flow down into the bowl during the refill cycle. This restores the level of standing water in the toilet bowl, keeping the trap sealed and preventing odors from escaping into the restroom.

Advancements In Flush Valve Technology

With the rise of environmental concerns and the need for water conservation, advancements in flush valve technology have been made to improve the efficiency of commercial toilets. One such advancement is the retrofit flush valve, which converts a manual flush valve into an automatic one. This technology allows for highly advanced features without the need for a complete system overhaul.

Another notable advancement is the use of touchless technology, which is becoming increasingly popular in both commercial and residential settings. Kohler’s Touchless Toilet, for example, uses a sensor in the flush lever to allow users to flush without touching the handle and spreading bacteria. This technology also includes a nightlight feature that can be adjusted through a mobile app.

In addition to touchless technology, water-saving toilets have also seen significant advancements in recent years. With regulations mandating that toilets use no more than 1.6 gallons per flush, manufacturers have developed new technologies to provide optimal water savings while still maintaining exceptional performance. Piston technology in flush valves has proved to be more predictable than diaphragm valves, with only a 6% variation in discharge from 15 psi to 125 psi.

Finally, sensor-operated valves have become standard in most public facilities due to their hands-free operation and reduced maintenance costs. Manufacturers are now competing to develop energy sources such as hard-wired transformers, batteries, solar power, and water power that use kinetic energy flowing through the valve.

Maintenance And Troubleshooting Tips For Flush Valves

To ensure that your commercial toilet flush valve is functioning properly, regular maintenance and troubleshooting may be necessary. Here are some tips to help you keep your flush valve in good working order:

1. Check the main water supply valve: Make sure that the valve feeding the fixture is open.

2. Inspect the flushometer valve screw: Ensure that no one has inadvertently adjusted the screw to close off water to the fixture.

3. Check for damaged handle assembly or internal parts: If the flushometer handle is leaky, does not cause the valve to flush, or does not return cleanly to its normal position, you may need to either replace the whole handle assembly or remove it and install replacement parts from a flushometer handle repair kit.

4. Inspect the relief valve inside the flushometer: A damaged relief valve can cause issues with flushing. Rebuild the relief valve internal parts using a repair kit available from the manufacturer.

5. Check for debris clogging of the bypass orifice: If your toilet continuously runs after use, there could be a blockage in the bypass component. Clean any debris or foreign objects impeding proper function.

6. Inspect for dirt or debris on the valve seat or in the valve seal area: Debris on these areas can cause issues with flushing. Clean them thoroughly to ensure proper function.

7. Drops in supply pressure: If you notice a decrease in pressure, check your facility’s line pressure and consult a professional for further steps.

8. Diaphragm assembly issues: A broken or compromised diaphragm assembly may require a complete replacement with a suitable gallons per flush (GPF) kit.

9. Relief valve problems in piston-type toilets: These toilets can fall victim to a worn relief valve that demands new components.

By following these maintenance and troubleshooting tips, you can keep your commercial toilet flush valve functioning properly and avoid any potential issues that could arise.