UL 193-2016 pdf download

UL 193-2016 pdf download.Alarm Valves for Fire-Protection Service.
16 Auxiliary Checks
16.1 Auxiliary checks are either bypass or alarm port types. An auxiliary check shall be so located that deposits or sediment will not tend to accumulate on the clapper or seat ring to an extent sufficient to interfere with intended operation.
16.2 An auxiliary check of the swing-check type shall comply with the applicable requirements relating to main-valve parts.
16.3 An auxiliary check of the vertical’nsing type shall be provided with guides or an appropriate housing which will serve as a guide, so as to prevent the check from sticking in the open position.
16.4 An auxiliary check shall have sufficient play between it and its supporting members so that the check can seat as intended
16.5 If an auxiliary check is supported on, or its housing is a part of, the main valve, the auxiliary check shall be allowed sufficient play so that after seating it will not have a tendency to hold the main clapper off its seat.
16.6 An auxiliary check-valve housing shall be provided with a through opening that will permit system pressure to assist in holding the check on its seat.
16.7 An auxiliary check valve of the vertical.rising type shall be provided with a spring as an aid to seating.
17 Retarding Chambers
17.1 The body of a retarding chamber shall be made of a material having corrosion resistance equivalent to cast iron.
17.2 Metallic diaphragms used in a retard chamber shall be made of a material having corrosion resistance equivalent to phosphor bronze.
17.3 A diaphragm used in a retard chamber shall be capable of withstanding 50,000 cycles of operation without failure, See 20.3.
17.4 The pressure retaining parts of a retarding chamber shall withstand, without rupture, a hydrostatic pressure of twice the maximum rated working pressure applied for 1 minute.
17.5 If a screen is employed in the piping between an alarm valve and a retarding chamber, it shall be made of corrosion-resistant material and shall be accessible for deaning and replacement.
17.6 The largest dimension of a hole in the screen shall be 1/16 inch (1.6 mm) less than the diameter of the smallest orifice to be protected by the screen. The total area of the openings in the screen shall be not less than 20 times the crosssectional area of the opening which the screen is designed to protect.
17.7 A retarding chamber shall include means for its support. If piping is to be used for this support, the pipe sizes to be used and the maximum lengths of pipe so used shall be stated on the instruction charts provided with the alarm valve. See 32.4.
17.8 A tapped opening of nol less than 3/4 inch pipe size shall be provided In a retarding chamber for connection of alarm devices.
18 Valve Gags
181 A valve shall prevent gagging of the valve. Openings which are intended to be plugged but which could be used for the insertion of rods or sticks or other similar objects which would gag the valve without requiring the removal of the cover or faceplate shall not be used.
PERFORMANCE
19 General
19.1 Representative samples of each size alarm valve, together with appropriate auxiliary devices for test, are to be furnished and subjected to the tests described in these requirements. Test bars of metal used in castings and additional samples of parts constructed of nonmetallic materials, such as valve-seat discs, are required for physical tests.
20 Metallic Materials Tests
20.1 Specimen bars of metals used shall be prepared from the same heat or run of metal used in the bodies and covers of valve samples submitted for investigation and test. The specimen bars shall comply with the minimum physical property requirements of the applicable ASTM or nationally recognized specifications.
20.2 A spring used in a valve mechanism shall operate as intended for 50.000 cycles.
203 A sample valve of any type employing a spring is to be connected to a hydraulic cylinder and subjected 10 50,000 cycles of intended operation. For clapper springs, the clapper is to be rotated off of the seat to a 45 degree angle and slowly returned to the closed position. For internal bypass springs, the bypass is to be operated from the full open position to the closed position. For retard chamber diaphragms, the diaphragm is to be flexed from the normally open to normally closed positions. These tests are to be conducted at a rate not exceeding 6 cycles per minute.