7270. Mills, C. K., [Brunswick Refrigerating Co.]. March 26. Lift valves; casings; strainers for valves and cocks.- Relates to screwdown valves specially applicable for ammonia refrigerating-machines. The valve is made of solid "stock" with a centre bore preferably of three successively increasing diameters, as shown in Fig. 1, and with inclined inlet and outlet borings 6, 7. The inlet and outlet pipes 9, 10 are secured to the casing by. means of tie-plates 11, Figs. 1 and 2, and tie-bolts 12, the joints being formed by annular flanges 14 and gasket 16. The screwed part of the stem 20 works in a bushing or nut 22 which is held in place against the shoulder 5 by a screw pin 23, and by the packing washers 26, the packing being compressed by a gland 27 and a screwed cap 28. In a modification, the stem screws into the outer cap 28 and the packing washers 26 are placed under the gland. A screen is also placed in the inlet 6 to exclude foreign matter from the valve. The valves may be readily ground by removing the packing. The two screw-threads 'in the outer cap of the modified valve may be of the same pitch so that the cap is removable without altering the position of the valve.
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