UL 565-2013 pdf download – Liquid-Level Gauges for Anhydrous Ammonia and LP-Gas.
4 Assembly 4.1 A gauge, when not assembled by the manufacturer as a unit, shall be arranged in as few subassemblies as practical; and shall be capable of being installed as a final assembly without alteration, other than for adjustment in the length of a gauging tube. 4.2 When a design requires the use of tubing, tubing fittings, pipe fittings, gaskets, bolts, cap screws, and the like, for making a proper installation, such parts shall be furnished by the manufacturer with each gauge when shipped. 4.3 The construction shall be such that parts can be readily reassembled in their intended manner after being dismantled to the extent needed for installation and normal care. 4.4 Convenient means shall be provided for the purpose of making any necessary field adjustment. 4.5 A brazing material used for joining fluid confining parts of a gauge for LP-Gas shall have a melting point (solidus temperature) not less than 538°C (1 000°F). Brazing shall not be used on assemblies for anhydrous ammonia. 4.6 A dial of a magnetic-float or of a rotary-tube type gauge intended to be installed on a container greater than 1 200 gallons for use with LP-Gas, and which is intended to be used for filling in accordance with the Liquefied Petroleum Gas Code, NFPA 58, shall be marked so that the maximum liquid level for butane, for a 50-50 butane-propane mixture, and for propane is readily determinable at temperatures between minus 7 and 46°C (20 and 1 1 5°F). Markings shall be in increments of not more than 1 1 °C (20°F). Exception: If the marked temperature range does not include minus 7 and 46°C (20 and 1 1 5°F), the gauge dial shall be marked in accordance with 1 6.4. 4.7 A dial of a gauge intended to be installed on a container greater than 1 200 gallons that is not to be used for filling shall be marked in accordance with 1 6.5.
4.1 0 A dial of a magnetic-float or of a rotary-tube type gauge for use only in LP-Gas aboveground containers of over 1 200 gallons (4542 L) water capacity shall be so marked. 4.1 1 Dial markings shall be legible and shall not be readily discolored or obliterated by weathering. 4.1 2 A gauge, other than for farm use as mentioned in 4.1 3, that requires the release of the contained fluid to the atmosphere to function, such as those of the rotary-tube, slip-tube, fixed-tube, and vent-valve types, shall be constructed so that the controlling orifice is not larger than a No. 54 (0.055-inch diameter) drill size. 4.1 3 A fixed-tube or a vent-valve gauge that is intended for mounting on a container for anhydrous ammonia used solely on farm equipment for field application of ammonia, is permitted to be constructed with a controlling orifice larger than that indicated in 4.1 2, but not larger than 7/1 6-inch diameter. Such a device shall be marked with the size of the opening.