| 摘要 |
536,271. Valves. CRAIG, W. N. Nov. 29, 1939, No. 31064. [Class 135] A non-return valve for use in association with a ball-cock to admit air to the supply conduit when this is being drained and so prevent liquid being siphoned out of the tank comprises a valve member 7 fitted with a facing washer 14 secured by a screwed ring 15 and formed with a stem 16 loosely engaging a hole in a partition in the casing 2. The valve seat is provided by a nipple 20 in an apertured plug 18 secured to the casing by a screwed ring 19. Projections 17 on the back of the valve member hold the valve member out of contact with the partition when it is moved across from its seat. The valve may be secured to the ball cock casing or to the top of a dip-pipe secured to the cock outlet. |
