| 摘要 |
The invention concerns a device for preventing back flow of liquid through an outlet pipe from a pump during times when the pump does not operate. A non-return valve (3) is arranged in the outlet pipe (2) from the pump (1) designed as a three-way valve. A ball (7) in the valve alternatively closes the inlet (4) to the valve and the outlet to a drainage pipe (6) resp. The ball (7) then takes one position which closes the drainage pipe (6) when the pump operates, while the drainage pipe is open and the inlet (4) closed when the pump is stopped. |
