Combination Exhaust and Relief/Venting Valve

摘要

This document discloses a steam valve for use on the low pressure exhaust side of a steam turbine including a housing having an inlet and two outlets with valves upstream of the outlets for selectively permitting steam flow from the inlet to either or both of the outlets. The valve arrangement includes a main valve, which acts as a turbine exhaust isolation valve, and an auxiliary valve which acts both as a relief valve and a personnel protection valve. During operation, when the main valve is open, the auxiliary valve acts as a spring loaded relief valve to relieve upstream over-pressurization, and, when the main valve is closed, the auxiliary valve is restrained open to act as a personnel protection valve to bleed or vent any leaked steam to the atmosphere. (Author)