Performance Requirements for Anti-Siphon Fill Valves for Water Closet Tanks
|Publication Date:||28 April 2008|
These devices are cold water supply valves that are installed within water closet tanks to provide tank refill and a trap reseal after flushing a water closet. They are equipped with backflow prevention devices or an air gap.
The device shall be designed to operate at a minimum pressure range of 20.0 psi to 125.0 psi static (137.9 kPa to 861.9 kPa).
Capacity - Total Fill and Refill
Original Equipment Manufacturer
When the device is furnished as original equipment with a manufacturer's water closet, the total flow capacity shall be sufficient to assure proper operation of the fixture in accordance with the performance standard, ASME A112.19.2. The device shall deliver a fill rate through the refill orifice as required by the water closet manufacturer.
When the device is furnished to retrofit water closets, the device shall deliver a minimum flow rate at 15.0 psig (103.4 kPa) flowing pressure of 1.5 GPM (5.7 L/min), and a minimum refill flow rate, through the refill orifice, of 20% of the total fill rate at 15.0 psi (103.4 kPa) flowing pressure.
Leakage and Spray Containment
The device shall not spray or otherwise leak water to the outside of the water closet tank during operation.
The device shall be equipped with a means to prevent backflow due to back siphonage. Air inlet ports shall be protected in such a manner as to reduce the risk of the intake of foreign material into the device.
A means shall be provided to secure the refill tube in its installed position.
Dimensional Criteria for Fill Valve Components
Dimensions for shanks, coupling nuts and locknuts shall be as shown in Figure 1. Thread dimensions shall be 15/16-14 UNS-1 per ASME/ANSI B1.1. See Appendix A.