| 摘要 |
In a fluid flow system, such as for central heating, the pipework includes a valve which may be regarded as a socket to which an appliance may be connected at will so as to utilise the fluid in the system, the valve being automatically maintained in closed position but opened by connection means on the appliance when the appliance is connected to the system. Preferably, a plurality of valves are provided at appropriate locations so that the appliance can be connected at any selected location, and the valve may control both outlet and inlet fluid flows. |
