Why is it important to recognize and conform to anti-siphon codes? Last Update: Sep 03, 2002

NOTE: Plumbing codes throughout the U.S. and Canada mandate the installation of anti-siphon toilet fill valves in all gravity flow toilets (new installations, retrofits, and replacements). The primary standard referenced in the U.S. is the ASSE 1002 Standard (Rev. 1999) and the similar CSA Standard B125 in Canada. Certification testing against these standards referenced in virtually all model codes adopted by various jurisdictions must be conducted by an ASSE Approved Test Laboratory.Under certain adverse conditions, toilet fill valves can be an “indirect cross-connection point” between the potable (drinking) water and non-potable water. Beyond the valve seat of the fill valve, the device and tank are part of the drain system. If a toilet fill valve is open and/or malfunctions when conditions in the supply piping cause a reversal of flow direction (due to a supply pressure drop or vacuum), back-siphonage of non-potable tank water into the drinking water supply can result. Backflow prevention codes are widely enforced. Fines have been imposed for the sale and installation of non-conforming toilet fill valves. Installers, their suppliers, and building owners are vulnerable to potential claims and/or lawsuits resulting from drinking water contamination traced to a non-anti-siphon toilet fill valve. INCIDENTALLY: Toilet fill valves were among the first end use water supply outlets designed to prevent back-siphonage of contaminates into drinking water. The first ASSE 1002 Standard was released in 1964. CESCO BRASS (Scovill and Burlington products) designed and produced anti-siphon ballcocks for at least 25 years before the ASSE Standard was developed.