Conditions play a role in choosing which type to use.
Diaphragm and piston flushing technologies have been around for decades, but plumbing engineers often still struggle with which one to specify. It’s really not about which one is “better.” Either diaphragm or piston could be the better choice, depending on the application. Although diaphragm flush valves are the right choice for the average commercial restroom, special environmental conditions may call for piston valves.
For some customers with multiple facilities, it’s not a matter of either/or; it’s both. The Charlotte Motor Speedway in Concord, N.C., sits on nearly 2,000 acres and includes a 2.5-mile road course, a 0.6-mile karting layout, a 0.25-mile oval within the walls of the 1.5-mile super speedway and a 0.20-mile oval. The speedway hosts three premium NASCAR events each year, plus more than 36 other events for automotive and motorsports fans.
Water conditions vary greatly between the speedway’s older and newer facilities, however. This made it necessary for the speedway to install both piston- and diaphragm-type flush valves.
“We have more than 1,000 Sloan flush valves of all types,” says Michael Gibson, head plumber at Charlotte Motor Speedway. Sloan Regal and Royal diaphragm flush valves are used in the main facility, which has 140,000 seats and 113 luxury suites.
Gibson adds the speedway uses Sloan GEM•2 and Crown piston flush valves in low-pressure and gritty water areas, including the Dirt Track of Charlotte and the zMAX Dragway, which are across the highway from the main speedway. The Dirt Track is a state-of-the-art 0.4-mile clay oval with 14,000 stadium-style seats. The zMAX Dragway, which boasts the world’s only four-lane all-concrete racing surface, has 40 suites and 30,000 grandstand seats.
Picking the correct flushometer technology for an installation calls for good, current information about how and where the valve will be used. And manual or electronic activation has nothing to do with the diaphragm vs. piston choice.