ASSE/IAPMO/ANSI/CAN 1055-2023

General 1.1 Application Chemical dispensing systems (herein referred to as the “device”) provide a means of mixing potable water with chemicals to provide the user with a chemical solution which is ready for use. The amount of dilution shall be fixed or adjustable. Devices covered by this standard are intended for stationary installations, mobile devices where the orientations are fixed, and hand-held devices. 1.2 Scope 1.2.1 Description This standard applies to those devices classified as chemical dispensing systems and shall be protected by an air gap complying to ASME A112.1.3-2000 (R2015), an integral elastomer gap, or an Atmospheric Vacuum Breaker (AVB). If an AVB is used as its method of backflow protection, it must conform with ASSE 1001 or CSA B64.1.1. 1.2.2 Pressure Range Devices covered by this standard are designed to withstand a water supply pressure of at least 861.9 kPa (125.0 psi) and operate within the full pressure range as indicated by the manufacturer. 1.2.3 Temperature Range Cold water devices covered by this standard are designed to withstand temperatures up to 48.9 °C (120 °F) and operate within the full temperature range as indicated by the manufacturer. Hot water devices covered by this standard are designed to withstand temperatures up to 82.2 °C (180 °F) and operate within the full temperature range as indicated by the manufacturer. 1.3 Mechanical Function 1.3.1 Elastomeric Gap The elastomeric gap shall be loaded to a normally closed position under static conditions. 1.3.2 Air Inlet The air inlet shall be force loaded (biased) to a normally open position when the line pressure is atmospheric. It shall be located above the pipeline so that water can drain from it by gravity. 1.3.3 Locations Devices shall have an air inlet that opens to atmosphere. The air inlet and the atmospheric vent shall be located at or downstream of the air gap or integral elastomer gap and upstream of the outlet so that water can drain from the vent by gravity.