The Steam Injector
A theoretical and practical treatise on the design and operation of injectors and on the flow of fluids through and the design of nozzles.

WATER CONTROL ARRANGEMENTS. 77 feed pipe at starting-, is illustrated at figs. 55 and 56, tig. 55 being a sectional elevation and fig. 56 an end elevation of the device. A non-return valve a is provided in the feed water .supply pipe b, which opens when the injector is in operation, and tends to draw water from said pipe, but closes immediately the injector ceases working, so as to prevent a return flow down said pipe to the hot well or feed tank. The injector is connected to the fitting by means of tlie union piece c. Fig. 57. Adjacent to and on the injector side of the valve a is pro- vided a by-pass or release connection d having a non- return valve e thereon. The latter closes (upon its seating f) when the injector is working normally, due to the difference in the pressures at its two sides, but isopened and held on its support ff by tlie pressure of the water in the feed pipe b above the valve a when the injector ceases working.. By the means aforesaid, the escape of tlie- hot water which remains in an injector when the steam supply is cut off is provided for, and the clifficulty experienced with lifting injectors when restarting after a short stop-