What is Thermal Expansion?
When heated, water expands. Under normal circumstances, a 40 Gallons hot water heater creates roughly an additional half gallon of water when heated (with no demand). In the past this expanded water would flow back into the public water supply. However, in many countries, where applicable by code, a backflow preventer is required, creating a closed system and a new problem as this extra half gallon of water is not compressible. When an expansion tank is installed the excess water enters the pre-pressurized tank. As the temperature and pressure reaches its maximum, the diaphragm flexes against an air cushion (air is compressible) to allow for increased water expansion. When the system is opened again or the water cools, the water leaves the tank and returns to the system.
Potential Problems Without an Expansion Tank
- Premature failure of the water heater may void the warranty of the water heater
- Dangerous high pressure
- leaky fittings and valves
- collapsed center flues
- flames out of combustion chamber
- Unnecessary Relief Valve Discharge
Installation Options for Thermal Expansion Tanks
- Install on the cold water side after the pressure reducing valve and between the backflow preventer and the water heater
- Do not install in an area where leakage could cause property damage
- The tank can be installed either vertically or horizontally. However, if the tank is to be installed horizontally, then it must be fully supported independent from the piping. Failure to do so will void the warranty.
Technical Features
- All tanks are NSF61 Certified
- MIG welding eliminates interior rough spots and sharp edges
- Each tank is factory leak tested
- 150 PSI Max pressure rating
- External baked epoxy-polyester coating provides a durable appliance finish
- Exclusive polypropylene liner eliminates internal corrosion
- Protected precharge valve eliminates potential leak path
Material Description
- Shell: Carbon Steel
- Connection: Stainless steel
- Diaphragm: Butyl
- Color: Almond
Operating Conditions
- Max. Operating Pressure: 150 PSI
- Operating Temperature: 210 Degrees Fahrenheit
- Factory Precharge: 40 PSI
- Warranty: 1 Year
Specifications
- Model Number: FTT5
- Tank Size: 2.1 Gallons
- Tank Weight: 6 Pounds
- Connection Size (National Pipe Thread): 3/4" Male Iron Pipe (MIP)
- Dimensions (LxWxH): 13" x 9" x 9"
- Acceptance Volume: 1.4 Gallons
- UPC Code: 80459513077
