UL-2443:2015 pdf free download – STANDARD FOR SAFETY Flexible Sprinkler Hose with Fittings for Fire Protection Service.
15 Stress-Corrosion Cracking of Stainless Steel Parts Test
15.1 Austenitic stainless steel parts, except braiding and anchoring component fasteners, shall show no evidence of cracking, delamination, or degradation after being subjected to boiling magnesium chloride solution. See 15.2—15.5.
Exception: Cracking is allowed when it does not impact the ability of the product to comply with the requirements of this Standard.
15.2 A representative section of hose and hose with end connection without plating or coatings is to be degreased prior to being exposed to the magnesium chloride solution. A sample hose is to be bent once to 900 at the minimum radius specified in the manufacturer’s installation instructions (the bent portion or part of the bent portion of the hose is to be used as the representative section of hose). In addition to the bent sample, a separate sample representative of the hose secured to the end connection is to be tested.
15.3 The sample is to be placed into a sealed glass chamber that is fitted with a thermometer and a wet condenser. The sealed glass chamber is to be filled approximately one-half full or to a level at least 0.5 inches (1.27 cm) above the test sample with a nominal 44 percent by weight magnesium chloride solution, placed on a thermostatically controlled electrically heated mantel, and maintained at a boiling temperature of 302 ±2°F (150 ±1°C). The sample parts are to be unassembled. The exposure is to last for 150 hours.
15.4 After the exposure period, the test samples are to be removed from the boiling magnesium chloride solution and rinsed in de-ionized water.
15.5 The test samples are then to be examined using a microscope having a magnification of 25X for any cracking, delamination, or other degradation as a result of the test exposure.
16 Elastomeric Parts Test
16.1 An elastomeric part used to provide a seal shall have the following properties when tested as specified in the Standard for Gaskets and Seals, UL 157:
a) For silicone rubber (having poly-organo-siloxane as its constituent characteristic), a minimum tensile strength of 500 psi (3.4 MPa) and a minimum ultimate elongation of 100 percent.
b) For natural rubber and synthetic rubber other than silicone rubber, a minimum tensile
strength of 1500 psi (10.3 MPa) and minimum ultimate elongation of 150 percent; or a minimum tensile strength of 2200 psi (15.2 MPa) and a minimum ultimate elongation of 100 percent.
c) Those properties relating to maximum tensile set; minimum tensile strength and elongation after oven aging; and hardness after oven aging, all as specified in UL 157. The oven time and temperature for oven aging is to be based upon the intended service temperature referenced in the manufacturer’s instructions, but not less than 60°C (140°F).
16.2 The Standard for Gaskets and Seals, UL 157, provides for the testing of either finished elastomeric parts or sheet or slab material. Sheet or slab material is to be tested when the elastomeric parts are 0-rings having diameters of less than 1 inch (25.4 mm). The material tested is to be the same as that used in the product, regardless of whether finished elastomeric parts or sheet or slab material is tested.