Commercial Flush Valve Parts Guide

Manual flush valves are frequently found in the busy bathrooms of airports, offices, schools, restaurants, and many other commercial buildings. Installing a new valve assembly or replacing an old one is easier when you understand the various components. This article is designed to provide you with an understanding of commercial flush valve parts and their basic functions.

Cover: Screws down over the diaphragm and fill plate for a sealed, watertight connection.

Body: A single piece consisting of inlets and outlets for water, and the threaded handle, cap, and vacuum tube connection.

Handle Coupling: This is a threaded nut with a center opening that slides over the handle and threads onto the body of the valve.

Handle Assembly: To activate the flush valve, the handle assembly connects into the valve body and dislodges the plunger with a stub at the end. This creates a vacuum, allowing water to flow through the valve until the pieces are realigned, which seals off the water flow and stops the flush.

Flush Connection: A tube that houses the vacuum assembly and connects the valve body to the threaded spud top and the toilet or urinal. Typically used with an outlet coupling and a gasket to seal the connection.

Spud Coupling and Spud Flange: Spud couplings are the connection from the flush connection vacuum tube to the urinal itself, and are often sealed with a gasket or plumber's putty. This connection is often covered by a spud flange for a more appealing appearance.

Control Stop and Supply Flange: Located where the water line exits the wall, and contains a slotted or keyed brass valve in the front. By turning the keyway valve, water can be shut off when the flush valve needs servicing. These are often installed with a supply flange to cover the wall opening behind the control stop for a more appealing appearance.

Outlet Coupling and Tailpiece: The tailpiece and outlet coupling connect either side of the main body of the valve to the wall valve with the water supply and to the vacuum outlet tube for flushing.

Spud Coupling: The images on this page show common spud couplings for urinals. Your existing spud coupling might be an older style installed with plumber's putty instead of the rubber gasket. It may also look and seal slightly different. It is always best to check for the manufacturer's recommended spud coupling. If manufacturer information is not available to select the correct spud coupling, you must know the size of your spud connection inlet pipe. Typically they are available in ¾" - 1.5" diameters and are determined by the flush connection tube size.

If you're looking to replace a manual flush valve with an automatic flush valve, Zoro has them available from a variety of leading manufacturers, along with automatic flush valve retrofit kits to upgrade existing assemblies.

Product Compliance and Suitability

The product statements contained in this guide are intended for general informational purposes only. Such product statements do not constitute a product recommendation or representation as to the appropriateness, accuracy, completeness, correctness or currentness of the information provided. Information provided in this guide does not replace the use by you of any manufacturer instructions, technical product manual, or other professional resource or adviser available to you. Always read, understand and follow all manufacturer instructions.