| 摘要 |
In the inlet pipe and the outlet pipe for hot water from a heating plant are inserted tube sections having the same inner cross-sectional area. In the tube sections, sensors for the velocity of the water flow are placed, activating contact means in a checking current loop, such that the state of the current loop (current or no current) is changed if the velocity of the water is different in inlet and outlet. In the current loop, an alarm relay or the coil of a magnetic valve shutting off the water supply is inserted. The flow sensors may be of a simple construction as shown in Figs 1 and 2, consisting of tube sections 1 having rectangular cross section, a swingable tongue 2 having an arm 4 with a contact piece 5 outside the tube being present in said tube sections. If such two flow sensors are positioned side by side, connection will be present between the contact pieces 5 as long as the water flow is equal through the two tube sections. <IMAGE>
|
