HYDRO-PRO : is our line of compact expansion tanks for sanitary hot water with a fixed potable water butyl membrane and internal epoxy coating. These expansion tanks are made of carbon steel and MIG welding that eliminates any sharp cutting edges inside the tank. The shape of the membrane is designed to avoid any water stagnation and therefore the growth of any bacteria. These expansion tanks are used with boilers, water heaters, pump systems and as anti-water hammer. The sizes range from 5 to 600 liters (1 to 132 UK gallons). They are certified according to PED 97/23 CE, WRAS, ACS, IAPMO and NSF. NPT fittings are available on request.