UL 1739-2017 pdf download
UL 1739-2017 pdf download.Pilot-Operated Pressure-Control Valves for Fire-Protection Service.
18 Spring Test
18.1 A spring used in a valve mechanism shall operate as intended when tested for 50,000 cycles of operation at a rate of not more than 6 cycles per minute. Each cycle of operatbon is to consist of a compression of the spring to Its minimum intended operating length (maximum compression during operation) and an extension back to its original length.
18.2 A sample valve Into which the cycled spring has been assembled then is to be subjected to at least three point checks horn the data generated during the Operation Test. Section 19, and the values obtained shall not differ by more than 10 percent from those obtained with as-received samples.
19 Operation Test
19.1 When tested as described in 19.3— 19.8, a valve shall operate without malfunction and shall perform in accordance with the manufacturers specihcations throughout the:
a) Rated inlet pressure range;
b) Rated outlet pressure range:
C) Flow range of the valve dunng the test. and
d) Control the downstream pressure when the valve is closed abruptly in accordance with 19.8 and 19.9,
19.2 A single sample is to be used for the operation tests defined in 19.3 — 19.9. As a result of the tests, the valve shall show no malfunction or detenoratlon of performance.
19.3 A valve incorporating an adjustable speed control device shall operate within time and pressure requirements specified In 19.5 and 19.8 when adjusted to its slowest operating position.
19.4 The inlet of a sample valve is to be connected to a piezometer to which a pressure gauge is attached and to a water supply that provides the rated Inlet pressure and maximum flow required. The downstream side of the sample is to be fitted with a piezometer equipped with a pressure gauge, piping, and a valve to control the water flow through the sample.
19.5 The sample is to be adjusted to a referenced setting yielding the lowest outlet pressure indicated in the installation instructions. The inlet pressure then is to be increased to the minimum inlet pressure recommended by the manufacturer, and the outlet pressure and flow is to be recorded. The inlet pressure then is to be increased in 50 psig (345 kPa) increments or less up to the maximum rated inlet pressure, and the outlet pressure and flow is to be recorded at each increment. Also, at each increment, the shutoff valve at the end of the test line that controls the water flow through the sample is to be adjusted to obtain a no (zero) flow condition and other intermediate flow rates up to the maximum rated flow. This procedure then is to be repeated at settings representative of the inlet and outlet ranges recommended by the manufacturer. The recorded outlet pressures at each increment and all flowing conditions shall be within ±10 percent of the referenced Outlet setting pressure. Except for the no (zero) flow condition, the time for the valve to return within ±10 percent of the outlet pressure referenced in the manufacturer’s instructions shall not exceed 5 seconds. After one minute at the no (zero) flow condition, the valve outlet pressure shall not exceed 15 psig above the referenced outlet setting pressure. See test procedures I and 2 in Table 19.1 for a description of test conditions.
19.8 After conducting the tests described in 19.5. a valve with a rated inlet pressure greater than 175 psi (1210 kPa) is to be adjusted to a referenced setting yielding the highest outlet pressure. The valve is then to be subjected to the rated inlet pressure while the valve is flowing approximately one-half the maximum flow recommended by the manufacturer, The shutoff valve at the end of the test line is to be closed from the partially open posibon so as to achieve a no (zero) flow condition at approximately 5 seconds after starting to close the shutoff valve. The recorded outlet pressure shall not exceed 175 psig (1210 kPa) or 10 psig (70 kPa) over the outlet pressure setting for valves with settings above 165 psig (1140 kPa), See test procedure 4 in Table 19.1 for a description of test conditions.
