| 摘要 |
A plumbing arrangement is described for a toilet pan connected to a waste disposal pipe. The waste pipe has an extension extending a short height above the flood level of the water trap. The upper end of the extension is closed off by a two way differential valve opening to the atmosphere. A cover is provided to permit the air flow to and from the valve but still to prevent the ingress of leaves or dirt which could have a detrimental effect upon the working of the valve. A number of embodiments of valve means are also described. |
