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Buffer Tanks

Dave_12 Member Posts: 77
Does anyone know of a good source of steel buffer tanks to add thermal mass to hot water heating systems. I am looking for insulated and non-insulated tanks in the 30 gallon to 200 gallon size range. Tanks need to be available in ASME and non-ASME construction depending on the application.

Some people use hot water heaters, but they do not have adequate size and quantity of fittings.

I would like to see: (4) 2" fittings for flow in and out; (2) 3/4" fittings for sensor and thermometer; (1) 3/4" top fitting for air vent; (1) 1" top fitting for pressure relief valve; and (1) 3/4" drain fitting. Construction should be 125 psi.

Black steel construction would be ok as the systems would be primarily closed to oxygen. Stainless steel or interior coated tanks would be ok for radiant system applications with non-oxygen barrrier tubing.

If anyone knows of a good source of tanks that would serve this application, please advise.



  • jeff_51
    jeff_51 Member Posts: 545
    80 gal galvanized well tanks

    I have used them for this purpose. YOu should get at least four tappings in most of them. Sensor and T-stat can of course be in the near piping of the tank. A releif valve with extended probe can be used on a tee at the top of the tank where I assume an outlet would go. Insulation can easily be installed with standard pipe covering especially for that purpose. I have used duct board for that purpose a number of times as well. You can of course get them bigger than that. Your supplier should be able to get them for you easily.
  • hr
    hr Member Posts: 6,106

    water heater manufactures offer blank insulated tanks. The larger sizes 80 gallon and up generally have 2" taps.

    Lochinvar has the RVU series from 120- 500 gallon with 3-6" connections!

    I have used electric water heaters. Remove the two elements and screw in a 1" close nipple and increase ut to 1-1/2 or larger with a bell reducer. There will be a small pressure drop at that connection, shouldn't bother you much at typical hydronic flows.

    LP tanks are available in a wide selection, even brand new they run about 2 bucks a gallon, uninsulated of course.

    Wessel and other manufactures will custom make just about any tank with any connection.

    I have messed with some HDPE tanks recently. Available inexpensivly at farm stores in a wide range of shapes and sizes. They are generally rated at 150°F however. I've run them to 160 but they start to get real soft! I would hate to see one burst with 300 gallons of 180° water flowing everywhere :)

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  • eric_2
    eric_2 Member Posts: 148
    AO Smith

    Try AO Smith @ www.hotwater.com and look at their hot water storage tanks. Hope it helps.
  • Paul Aguilar
    Paul Aguilar Member Posts: 9
    buffer tanks

    Quietside has a 20 gallon buffer tank with all the taps and controls you're looking for. They also have a 50 gallon and 80 gallon tank that is more for hot water storage rather than buffering, but probably can be used as a buffer.
    I don't believe the tanks are on their web site but they can send your brochures. See their web site: Quietside.com
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