I've got one on my tank, go to eBay and type in caravan 1/2 non return valve it will fit straight in garden hose pipe.
You could use one of these:http://www.gardinerpolesystems.co.uk/acatalog/john-guest-3-8-inch-single-check-valve.htmlWith one of these at each end:http://www.gardinerpolesystems.co.uk/acatalog/3-8-inch-john-guest-stem-to-1-2-inch-barb.html
Quote from: Alex Gardiner on August 16, 2013, 08:24:07 pmYou could use one of these:http://www.gardinerpolesystems.co.uk/acatalog/john-guest-3-8-inch-single-check-valve.htmlWith one of these at each end:http://www.gardinerpolesystems.co.uk/acatalog/3-8-inch-john-guest-stem-to-1-2-inch-barb.htmlsays no stock on bottom one
http://www.ebay.co.uk/itm/Caravan-Motorhome-Whale-1-2-Plastic-Non-Return-Valve-/261202962690?pt=UK_Campervan_Caravan_Accessories&hash=item3cd0e8e902
Where do you fit the valve?Vin
So that's between the tank and the pump?Vin