| 摘要 |
<p>Owing to the level of pollution of the liquid coolant flowing through the tubes of heat-exchangers of air-conditioning units and condensers it is essential to clean the tubes at regular intervals by means of mechanical cleaners, such as brushes. The valve required for the purpose of reversing the normal flow must be of small dimensions, robust and of simple design. For this a valve (1) is proposed in which two pipe ends (3-4) (5-6) are each arranged in their respective planes, and in which the plug (9) is supported movably. The plug has, for this purpose two flow passages (15-16) in the normal direction which connect the pipe ends by the shortest route. For the reverse direction, the plug is fitted with two spirally-shaped passages (17-18) which independently connect, in a cross-over manner, the pipe ends.</p> |
