Is my valve a "Torbeck"?

I have a unit called a "Water Geezer" to control mains water filling of a caravan water container. It sits on the top of a steel cylinder with a float inside the container. The water flow will not stop and it has been suggested that it is a "Torbeck" valve. It has a little lever which closes a pin-hole but no diaphragm. Have you come across it and is the problem a missing diaphragm. Any help would be appreciated. Michael