Historical
ANSI Z21.22-1999/CSA 4.4-M1999 (R2008)
ANSI Z21.22-99(R08)/CSA 4.4-M99(R08) - Relief Valves for Hot Water Supply Systems
1. Scope
1.1.1 This standard applies to the following types of relief valves constructed entirely of new, unused parts and materials:(a) Temperature relief valves and combination temperature and pressure relief valves for use on storage tanks of hot water supply systems without heater input limitation "T&P" valves, hereinafter called.
(b) Valves having only pressure relief features for use on storage tanks of hot water supply systems without heater input limitation.
(c) Vacuum relief valves.
1.1.2 A temperature relief valve, or a T&P valve shall operate when the temperature sensing element is at 210F (99C) or less. A device with a higher operating temperature is not acceptable under this Standard.
1.1.3 A vacuum relief valve shall be of a single-purpose type.
1.1.4 All references to psi throughout this standard are to be considered gage pressures unless otherwise specified.
1.1.5 Exhibit A contains provisions that are unique to Canada.
CONTENT PROVIDER
CSA America, Inc. [csa]
CSA America, Inc. [csa]