Feeling Flush

By David Thompson

Flush valves have been a part of our society since the early 1900s. Even though the principles on which they function haven’t changed much over the last century, today’s flush valves are a far cry from that first generation. Those first flush valves were designed to flow as much water as possible in a short amount of time to empty and clean the fixture.

As time progressed and the U.S. population grew, the demand for water was also growing, but at an exponential rate. It became increasingly apparent that the need for flush valves that used less water was vital. In 1992, the EPA Act reduced the amount of water that could be used in a toilet from 3.5 gallons per flush (gpf) to 1.6 gpf, and urinals were reduced from 1.5 to 1.0 gpf. While the amount of water used during each flush cycle was being reduced, advances in manufacturing allowed for tighter tolerance, resulting in much better accuracy. The 1980s saw the introduction of sensor flush valves in restrooms. The need for hands-free restrooms was brought about by a demand for cleaner and more sanitary restrooms and reduction in germ contamination.

Building owners today are demanding better flush valve performance and water conserving flush volumes. Through advances in technology, flush valves today can meet these demands with lower flows, better sensors and electronics and even with alternative power sources. Electronic (battery or hardwired) flush valves today require less voltage, which has resulted in greater battery life or reduced requirements of a building’s electrical system. These lower powered flush valves are also using better sensor technology. Advances in infrared technology over the years have greatly reduced unwanted flushing and increased the accuracy of user detection.

The newest generations of flush valves offer alternative energy power sources, either solar or hydro-generated power. Solar valves convert light in the restroom into electrical energy to power the system, while hydro-generated valves use turbines that spin as the valve is flushed to create power. High efficiency valves are available not only in alternative power but also in battery, hardwired and traditional manual flush valves. These valves are offered from1.28 gpf for toilets all the way down to 0.125 gpf for urinals. These systems not only help building owners conserve water, but they also greatly reduce overall operating costs.

When architects and engineers are specifying flush valves for facilities, key issues such as performance, sustainability and the cost of the valve over its expected life cycle need to be evaluated. Before these issues can be addressed, however, specifiers need to know what a customer is looking for in restroom equipment.

Are they looking for a manual or sensor activated valve, diaphragm or piston operated, standard flow or a high efficiency system? The answers to these questions will lead specifiers to the type of flush valve that is required for a project. Once the type has been determined, specifiers can look at several manufacturers and begin addressing a product’s performance, sustainability and LCA, or Life Cycle Cost, which is the cost of the flush valve over its entire life expectancy.

When addressing valve performance, it’s important to note that it’s not just about the stated flow rate or the minimum pressure at which the valve can be operated; it’s about repeatable performance. Flush valves that offer accurate and consistent flushes time after time help to maintain a plumbing system’s performance, and they save water. Some manufacturers’ flush valves can have a “break in” period, in which higher volumes of water are used; in facilities that are using high efficiency systems, the extra water can cause problems such as splashing and overflows. Other manufacturers’ valves can have flush volumes that degrade over time from internal part wear, which leads to short flushes, thus, until new replacement parts are installed, a double flush may be required to evacuate fixtures.

Sustainability concerns flush valves that, once installed, will not have to be “touched” again for maintenance for years to come. There are a lot of low flow valves on the market that, while they may use less water and offer return on investment through water usage reductions, can still consume internal parts on an annual basis. Whether those parts are batteries, gaskets, seals or internal kits, they still must be replaced; the old parts wind up in the trash. Alternative energy-powered flush valves help reduce battery replacement cost and disposal, but, if the valves use traditional black rubber seals and gaskets, routine maintenance will still need to be performed. Newer advances in flush valve seals, gaskets and internal kits’ material compositions allow the internal parts to last longer in today’s potable water supply, even with increased levels of chloramines.

Finally, the LCA, or cost of the flush valve over its expected life cycle, needs to be determined. Tied to both the performance and sustainability of the valve, life cycle costs incorporate all the cost associated with ownership of that flush valve. The initial product purchase cost historically has been the key factor in decision making. Today’s building owners are not only looking at the initial purchase and installation cost but also at the maintenance that will be required over its entire expected life. The cost to repair and maintain some flush valves over a 15 – 20 year time period often winds up being more expensive than the original valve cost. Flush valves that have the lowest life cycle cost while maintaining high performance are what owners are looking for today.

Today’s building owners are demanding more for their dollar when it comes to their facility and the products that are installed. When owners are considering a new building, they are not only concerned about the upfront cost but also about what it will cost to operate it over the next several decades. Restroom products might be small in cost compared to other required building systems, such as HVAC, but making the right choices today can add up to big savings versus expenditures later. Using flush valves that perform consistently, use advanced seals and gasket materials and operate on alternative energy power sources will result in restrooms that save building owners money, and they will not have to worry about throwing money down the toilet.

David Thompson is the sales and marketing coordinator for the Zurn Commercial Brass Operation.