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Washington Administrative Code (Last Updated: November 23, 2016) |
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Title 296. Labor and Industries, Department of |
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Chapter 296-96. Safety regulations and fees for all elevators, dumbwaiters, escalators and other conveyances. |
Section 296-96-16220. What requirements apply to valves, supply piping, and fittings?
Latest version.
- (1) Valves, piping and fittings must not be subjected to working pressures that exceed manufacturer recommendations.(2) Pipes, especially those that may vibrate, must be sufficiently supported at each joint and fitting so undue stress is eliminated.(3) A shut-off valve must be installed in the pit.(4) Each pump must be equipped with a relief valve and all relief valves must be:(a) Located between the pump and check value in a bypass connection;(b) A type that cannot be shut off from the hydraulic system; and(c) Pre-set to open at a pressure not greater than 125 percent of the working pressure at the pump.EXCEPTION: Relief valves are not required for centrifugal pumps driven by an induction motor when the shutoff or maximum pressure that the pump develops is no more than 135 percent of the working pressure at the pump.(5) A check valve must be installed that will hold a car and its rated load at any point whenever a pump stops or pump operating pressure drops below the required minimum.