UL-72:2015 pdf free download – STANDARD FOR SAFETY Tests for Fire Resistance of Record Protection Equipment.
9 Combined Explosion Impact Test
9.1 At the option of the manufacturer, the fire-impact test and the explosion test may be combined and conducted on one sample of the equipment.
9.2 In the combined test, the explosion test as described in 8.3.1 is to be conducted.
9.3 If no explosion results during 30 mm at 2000°F (1090°C), the furnace temperatures are to be reduced
to those specified in Appendix A and the fire continued for an additional 30 mm for equipment to be rated
4 or 3 h, and for an additional 15 mm for equipment to be rated 2 h. No additional exposure is required
for equipment to be rated 1 or 1/2 h. After exposure to the fire for the total period required for the desired
classification, the furnace fire is to be extinguished and the test sample withdrawn.
9.4 The impact test is then to be continued as described in 7.3.3 — 7.3.5.
10 Gasket Materials
10.1 Neoprene or rubber gaskets (except those made of foamed material), when employed, are to be tested to demonstrate compliance with the following properties:
a) Minimum tensile strength — 850 pounds per square in (psi) (5.86 MPa) and minimum ultimate elongation — 250 percent (1 to 3-1/2 units);
b) Maximum set of 1/4 in (6.4 mm) when 1 in (25.4 mm) marks are stretched to 2-1/2 in (64 mm), held for 2 mm, and measured 2 mm after release;
c) After 70 h in an air oven at 100°C ±2°C (21 2°F ±3.6°F):
1) Minimum percent of original tensile strength —75.
2) Minimum percent of original elongation — 65.
10.2 Foamed neoprene or rubber gaskets, when employed, are to be tested to demonstrate compliance with the following properties:
a) Minimum tensile strength — 65 psi (0.45 MPa) and minimum ultimate elongation — 100 percent.
b) After 70 h in an air oven at 100°C ±2°C (21 2°F ±3.6°F):
1) Minimum percent of original tensile strength —75.
2) Minimum percent of original elongation — 65.
10.3 Thermoplastic gaskets, if employed, are to be tested to demonstrate compliance with the following properties:
a) Minimum tensile strength — 1200 psi (8.27 MPa) and minimum ultimate elongation —250 percent (1 to 3-1/2 units).
b) After 7 days in air at 87°C (189°F):
1) Minimum percent of original tensile strength — 90.
2) Minimum percent of original elongation — 75.
MARKING
11 General
11.1 Record protection equipment shall be marked with the manufacturer’s or private labeler’s name or identification and the rating as determined by the tests described in these requirements. This marking shall be applied to the device and located so as to be readily visible after the unit has been installed.
11.2 Multi-rated equipment shall have a marking on each storage compartment or drawer indicating the storage compartment’s or drawer’s Class rating. The marking shall be located where readily visible on the storage compartment or drawer. This supplementary marking shall be referenced on the main equipment marking.
11.3 If a manufacturer produces record protection equipment at more than one factory, each device shall have a distinctive marking to identify it as the product of a particular factory.