Current regulations require a number of safety features to be designed into a multivalve. These include: a non-return fill valve automatic shut-off at 80% full a pressure relief valve an electrically operated shut-off output valve. Older valves often fail to meet this specification. If your multivalve is not marked E67R-01, you should change it. These valves are designed to be mounted at 0 degrees (i.e. horizontal), at the top edge of the tank. This product does NOT include a level sender – these are sold separately. You must fit a valve that matches the depth of the tank. Select your tank depth from the drop-down list.