Abstract: An attemperator in the form of a steam desuperheater is disclosed herein and comprises a water tube adapted to be connected to a source of water under high pressure and a spray tube communicating with the water tube through a flow-control device for controlling the flow of water from the water tube to the spray tube. The spray tube is adapted to be located in a steam line for injecting cooling water into the steam when its temperature exceeds a predetermined temperature and accordingly is formed with one or more nozzles for injecting a spray of water travelling along an expanding swirling path into the steam, the water being atomized into small droplets which easily evaporate in the steam. Preferably, a plurality of nozzles are provided arranged in rows extending axially of the spray tube and the rows are circumferentially spaced apart. Also, the nozzles preferably communicate with the inside of the spray tube through a series of small ports.

Abstract: The preferred embodiment of the invention disclosed herein includes a main check valve responsive to the rate of flow of fluid to a demand system and a bypass valve metering the flow of fluid to a bypass system. In the closed position of the main check valve, the bypass valve is in a fully open position whereby a predetermined minimum flow from a pressure source is maintained; in an intermediate position of the main check valve responsive to the predetermined minimum rate of flow thereacross, the bypass valve is closed and remains closed from the intermediate position of the main check valve to the fully open position. Operation of the bypass valve is controlled by fluid pressure from the inlet side of the main check valve which acts on a piston associated with the bypass valve and the buildup of pressure is controlled by a pilot valve.

Abstract: The preferred embodiment of the invention disclosed herein includes a main check valve responsive to the rate of flow of fluid to a demand system and a bypass valve metering the flow of fluid to a bypass system. In the closed position of the main check valve, the bypass valve is in a fully open position whereby a predetermined minimum flow from a pressure source is maintained; in an intermediate position of the main check valve responsive to the predetermined minimum rate of flow thereacross, the bypass valve is closed and remains closed from the intermediate position of the main check valve to the fully open position. Operation of the bypass valve is controlled by fluid pressure from the inlet side of the main check valve which acts on a piston associated with the bypass valve and the buildup of pressure is controlled by a pilot valve.