ASME A112.4.1-2009 pdf free download.Water Heater Relief Valve Drain Tubes.
ASME A112.4.1 establishes performance requirements and test methods applicable to water heater relief valve drain (or runoff) tubes for use with relief valves having a steam rating of 105,000 Btu/hr or less.
1.2 Reference Standards
The following reference standards shall be used to evaluate the product, and are cited herein. Unless indicated, the latest edition of these standards shall be applicable for certification to this Standard.
ANSI Z21.22, Relief Valves for Hot Water Supply Systems
Publisher: International Association of Plumbing and Mechanical Officials (IAPMO), 20001 Walnut Drive, South Walnut, CA 91789-2825 (www.iapmo.org)
ASME B1.20.1, Pipe Threads, General Purpose (Inch)
Publisher: The American Society of Mechanical
Engineers (ASME), Three Park Avenue, New York, NY
10016-5990; Order Dept: 22 Law Drive, P.O. Box 2900,
Fairfield, NJ 07007-2900 (www.asme.org)
The drain tube shall have a minimum inside diameter of in. and a minimum length of 48 in.
The material that is used in the composition of the drain tube shall be capable of withstanding the temperature tests cited in section 3 without collapse or permanent distortion. MateriaLs shall be corrosion resistant.
Any joints within the tube shall be firmly affixed and shall withstand the temperature tests without separation or leakage. Assembly of the drain tube to the relief valve shall be possible by hand-tightening only. Connecting threads shall comply with ASME B1.20.1 for 3/4 in. NI’!’ pipe threads.
2.4 Installation Instructions
Installation instructions, including post-installation relief valve testing procedures, shall be provided with the unit. A permanent tag or label relating to the relief valve test procedures shall be provided with the device.
2.5 Marking and Identification
2.5.1 The manufacturer’s name or trademark shall
be permanently marked on the drain tube.
2.5.2 For products intended for other than OEM applications, the limitations of installation for the drain tube shall be permanently marked on the tube in lettering not less than 0.125 in. in height. For example, “HAND-TIGHTEN ONLY,”“USE ONLY ON T & P VALVES WITH 105,0(N) Btu/hr OR LESS RATING,” or “NO PIPE SEALANTS.”
3 TEST METHODS AND PERFORMANCE REQUIREMENTS
3.1 Temperature Test
3.1.1 Test Equipment. A steam-generating source capable of producing 105,000 Bhi/hr at 15 psig pressure and 250°F temperature shall be used to conduct this test. The steam source shall be fitted with instruments that measure pressure and temperature. The steam source shall be connected to a -th. relief valve that complies with ANSI Z2L22. The relief valve shall be mounted horizontally and the drain tube shall be installed in a downward position. For drain tubes intended for instal. lation in relief valve locations at the top of a water heater, the test assembly shall be installed with the relief valve in a vertical position and the drain tube connected and tested accordingly.
3.1.2 Test Method. Prior to conducting this test, the inside diameter and length of the drain tube shall be measured and recorded. A thermocouple shall be attached to the outside surface of the drain tube within 3 in. ± 0.5 in. of the relief valve in order to measure the equilibrium temperature.