ASME B16.40:2019 pdf free download

ASME B16.40:2019 pdf free download
ASME B16.40:2019 pdf free download.MANUALLY OPERATED THERMOPLASTIC GAS SHUTOFFS AND VALVES IN GAS DISTRIBUTION SYSTEMS
6.3.3 Sustained-Pressure Test. Each basic valve design shall be subjected to the sustained-pressure tests described herein to evaluate the long-term pressure integrityofthe valve shell and closure elements. All valves shall be in the open position for the pressure-boundary test [see (a)] and in the closed position for the valve closure test [see (b)].
For both PE and PA-11, Table 6.3.3-1 offers two choices of pressures and duration times for the sustained pressure test. The valve manufacturer shall test for 1,000 hr at the lower listed pressures, depending on valve DR, or for 170 hratthe higherlistedpressures. Eitherchoice is valid. The valve manufacturer is not required to perform both tests. ForNVS < 1 1 ∕ 4 , the sustained-pressure tests mayuse Table 6.3.3-1 DR 9.3 pressure values.
The valves shall not fail, as defined in ASTM D1598, when subjected to the sustained pressure test.
(a) Pressure-Boundary Test. Six samples of each basic valve design shall be connected at both ends to thermo- plastic pipe of appropriate wall thickness of a length at least 5 times its outside diameter or 20 in. (510 mm), whichever is less. These assemblies shall be subjected to a sustained-pressure test chosen from the sustained test pressures and minimum durations listed in Table 6.3.3-1. The DRvforthe valve shall be used in determining the test pressure. Failure oftwo ofthe six samples tested shall constitute failure in the test. Failure ofone ofthe six samples tested is cause for a retest of six additional samples. Failure of one of the six samples in retest shall constitute failure in the test. Failure of a test sample shall be as defined in ASTM D1598.
(b) ValveClosureTest. Oneofeachvariationindesignor material ofthe closure element and/or seat seals ofeach nominal valve size shall be tested in the closed position. One portshall be pressurized to 1.1 times the valve design pressure and the opposite port open to atmosphere. The pressure shall be maintained for a minimum of170 hr at 176°F (80°C) or for 1,000 hr at 100°F (38°C). There shall be no evidence ofleakage (breakingawayofbubbles) past the closure element for the duration of the test.