An expansion tank is generally installed directly above the water heater by means of a tee-fitting installed in the cold water delivery pipe. The expansion tank is usually installed horizontally, though it is acceptable to install it vertically if it is necessary because of space limitations. Jun 26, 2011 I recently had a hot water heater and thermal expansion tank installed by a licensed plumber. I was not present at the install. Other #2 used often around here is to mount the tank upside down right above the tee and use the bull of the tee to aim towards the back wall, turn up just past the tank, install your valve and pipe to the wall as.
Best online strictly PLUMBING help, advice, dyi, and informational forum. Questions and discussions about toilets, sinks, faucets, drainage, venting, water heating, showers, pumps, water quality, and other exclusively PLUMBING related issues. Please refrain from asking where to purchase a product, or business, pricing, or legal questions, or for contractor referrals, or any questions not related to plumbing. Keep all posts positive and absolutely no advertising. This site is free, ad free, pop-up free and made possible by:
expansion tank mounting |
---|
Author:Fixitangel (NC)
Just wondering if there is a preferred way to mount an expansion tank for a water heater.. I've seen some where the tank is above the water line, others times it's hanging below. Does it matter? Thanks all.
|
Re: expansion tank mounting |
---|
Author:Shoemaker2 (MA)
Up or down is fine you just don't want it sideways for the stress on the threaded nipple.
|
Re: expansion tank mounting |
---|
Author:CanuckWolf (Non-US)
the inspectors in our area want to see the expansion tank to be 'strapped' for support.i try to hang it high so no one knocks it around.
|
Re: expansion tank mounting |
---|
Author:hj (AZ)
Whichever way is the easiest to bracket it. Down, it is not fighting gravity, however.
|
Re: expansion tank mounting |
---|
Author:mo1258 (TX)
I like up myself - I think it is easier on the bladder inside the tank but function outweighs form on this one. 'Easiest' takes the prize. Like many things in life, good 'support' is essential!
|
Re: expansion tank mounting |
---|
Author:LemonPlumber (FL)
You need to make the plumbing work.The weigh and the fact that it sticks out like a sore thumb is important.just remember where you support it should leave access for checking or servicing. I like the ones on copper standing right on top of the inlet.But run over and balance them upside down on the edge of the heater,on cpvc installs.
|
Re: expansion tank mounting |
---|
Author:AW Plumb (SC)
Lemon, CPVC? Really? You still install CPVC for new work? Anyway, Angel, My vote is down.. As previously stated up is fine when you can't let it hang... But never 'whoppy jawed', My father-in-law's term for crooked or at an angle....
|
Re: expansion tank mounting |
---|
Author:LemonPlumber (FL)
Copper is the tubing of choice.cpvc is the other end.Have no notable problems with the tubing.It is/ silly string to me so the expansion tank may look unusual.It is about function, when less than copper is a plumber tubing!Pex is just another silly string.If I the customer knew starting a new home the water might eat copper,I would still prefer copper and treat to protect the tubing that does protect/ the served water.We have started to use copper fitted supply lines to aid the fixtures where no other water quality checks are in place.Yes ,even on the lessor plastic type homes.
|
Re: expansion tank mounting |
---|
Author:Fixitangel (NC)
Thanks AW:
But never 'whoppy jawed', My father-in-law's term for crooked or at an angle.... In these parts there's a saying that if something is out of plumb, it's either leaning to the liquor store or towards the beauty shop |
Re: expansion tank mounting |
---|
Author:bernabeu (SC)
I believe y'all mean 'compression' tank.
Expansion tanks, which are open to atmosphere, are basically obsolete (they were used in the attic to absorb expansion from gravity flow (large pipe size) hydronic heating systems. I do believe the nit has passed away |
Re: expansion tank mounting |
---|
Author:CanuckWolf (Non-US)
no, it's an expansion tank...it may be a 'closed', diaphragm expansion tank, but, it's an expansion tank none the less.
|
Re: expansion tank mounting |
---|
Author:dlh (TX)
you are thinking in ancient terms/times. today an expansion tank does not have to be open to the atmosphere
it is because of the advanced technology we have in the 21st century, it gives us the ability to do things that were unheard of in older times - - - - - - - PLUMBERS 'Protecting The Health Of The Nation' |
Re: expansion tank mounting |
---|
Author:bernabeu (SC)
NOOOOOO.......
words have meanings, different words have different meanings; a compression tank is used in a CLOSED pressurized system to absorb the expansion of the entrained air in the fluid whether hydronic, chilled, or heated potable water (water is NOT COMPRESSIBLE, nor does it expand) an expansion tank is open to atmosphere and would be primarilly used as a reservoir for the enlaged volume of heated fluid .. eg. gravity hydronic systems (still in use in industrial heating/cooling systems) COMPRESSION TANK: [www.bellgossett.com] EXPANSION TANK: [www.helpwithdiy.com] obviously you have never had to opportunity to work on anything larger than a one story private home or maybe a quonsett hut type business |
Re: expansion tank mounting |
---|
Author:SMSPlumbing (MD)
Not to jump into this argument but here is my 2 cents. They have termed the sealed tanks 'expansion tanks' because they absorb the thermal expansion as water is heated. When you go to a supply house you dont ask for a compression tank. They will look at you funny and say you mean an expansion tank.
[en.wikipedia.org] Edited 1 times. |
Re: expansion tank mounting |
---|
Author:bernabeu (SC)
...and when you ast for a TeeWye they will actually give you a sanitary branch tee
(a true TeeWye is a one piece lateral Y with an integral 45) the fact that most places are actually clueless and cater to the lowest common denominator in order to make a quick buck does not change proper nomenclature ps. i did say the nit has been picked |
Re: expansion tank mounting |
---|
Author:bernabeu (SC)
as per Bell&Gossett: <diaphragm-type compression tank>
|
Re: expansion tank mounting |
---|
Author:SMSPlumbing (MD)
I say 'potato' You say 'potaato' The expansion compresses the bladder. There, both are covered
|
Re: expansion tank mounting |
---|
Author:bernabeu (SC)
I once was privy to observing a puchasing agent order 1,600 - 8X6 'true' wyes from Flagg Fitting on a cast to order basis. The agent at Flagg verified that the customer said 'true wye' and placed the order @ $137.50 each. Unfortuneately for the P.A. a true wye is shaped liked a CAPITAL Y and the job required (as per the 'prints') lateral (branch) wyes (shaped like a lower case y). OOOPS! Words have meanings, different words have different meanings. I am not rambling ... this applies directly to reading the code WITHOUT 'interpretation'. if one were to order 10 gallon expansion tanks ? if one were to order 10 gallon compression tanks ? if one were to order 10 gallon diaphragm-type compression tanks ? would one be shipped the same item ? Is not nit-picking fun ? |
Re: expansion tank mounting |
---|
Author:dlh (TX)
all i know is i go by what my suppliers know the product as.
i never heard of a teewye until i started looking at this site and the fitting books i use (charlotte pipe online) call them combination wye and 1/8th bend or sanitary tee depending on what you are calling a teewye as it still confuses me - - - - - - - PLUMBERS 'Protecting The Health Of The Nation' |
Re: expansion tank mounting |
---|
Author:bernabeu (SC)
a teewye is a one piece fitting that combines a lateral y and a 1/8 bend into one fitting ... they may be used horiz and vert
a sanitary tee is a fitting to be used on the vert only .. just a slight downwards curve at the t a (sanitary) y is a lateral y (a tee with a 45 degree bull piece) .. horiz and vert ok while sanitary cross tees are commonly used for back to back fixtures .. try snaking through one a 2x6 wall with a teewye cross fitting is the 'best practice' ... the snake will ALWAYS be guided downward once upon a time, in a plumbing world long long ago ...... quality |
Re: expansion tank mounting |
---|
Author:dlh (TX)
i care less what the specifics for a teewye are as that is not the proper name given them by the manufacturers or used in my area
- - - - - - - PLUMBERS 'Protecting The Health Of The Nation' |
Re: expansion tank mounting |
---|
Author:bernabeu (SC)
[www.toolingu.com] [www.bing.com] [www.buyhardwaresupplies.com] 'read 'em and weep' Edited 1 times. |
Re: expansion tank mounting |
---|
Author:dlh (TX)
ok, i was talking U.S. manufacturers
oh and 2 of those sites are not manufacturers - - - - - - - PLUMBERS 'Protecting The Health Of The Nation' |
Re: expansion tank mounting |
---|
Author:bernabeu (SC)
...ok...
a tee is a fitting with a 90º 'bull' a wye is a (tee) fitting with a 45º 'bull' a teewye would be? ... a rose by any othe name is: Kingdom: Plantae (unranked): Angiosperms (unranked): Eudicots (unranked): Rosids Order: Rosales Family: Rosaceae Subfamily: Rosoideae Genus: Rosa |
Re: expansion tank mounting |
---|
Author:dlh (TX)
again
we do not use that term in my area and neither do any of the manufacturers i deal with it sounds like someone made the name up because they didnt know the proper name for the fitting. its like calling it a 'whatchamacallit' but giving a specific name to the item - - - - - - - PLUMBERS 'Protecting The Health Of The Nation' |
Re: expansion tank mounting |
---|
Author:bernabeu (SC)
i repeat:
'' What is the definition of tee wye? A pipe fitting that joins one pipe run to another that initally runs in one direction at 45° and eventually tapers to 90 degrees. Learn more about tee wye in the class 'Fittings for Fluid Systems 135' below. Fittings for Fluid Systems 135 Hydraulics and Pneumatics Training '' last i heard; water was a fluid (even when it contains waste) this is from most 'piping 101' classes ps. i'm done |
Re: expansion tank mounting |
---|
Author:dlh (TX)
again, it is a made up word
- - - - - - - PLUMBERS 'Protecting The Health Of The Nation' |
Re: expansion tank mounting |
---|
Author:LemonPlumber (FL)
Bern not sure.but the old compression tanks are fitted with 3/8 ip for air pressure bleeders.Where expansion tanks have shader valves to set the intended pressure.Believe the use was near the same minus the ability to off vent extra air pressure volume.Another mechanical wonder.
|
Re: expansion tank mounting |
---|
Author:CanuckWolf (Non-US)
*wikipedia def.-An expansion tank or expansion vessel is a small tank used in closed water heating systems and domestic hot water systems to absorb excess water pressure, which can be caused by thermal expansion as water is heated, or by water hammer.
The vessel itself is a small container divided in two by a rubber diaphragm. *Amtrol's explanation(the company who invented and marketed for use the diapragm expansion tank in 1954) Thermal expansion occurs as domestic water is heated. Left unchecked, the resulting pressure increase can cause relief valve discharge and other potentially unsafe conditions. Therm-X-Trol® expansion tanks absorb this expanded water, keeping water pressure at a safe level Water heater manufacturers and plumbing codes require the installation of an expansion control device if a backflow preventor, pressure reducing valve or check valve is installed in the domestic supply line. ...and a picture of what i use in homes today. |
Re: expansion tank mounting |
---|
Author:bernabeu (SC)
compession - expansion .... terminology gets dumbed down to suit the users
@ home depot, for example, they call a 1/2'NPT X 4'NPT piece of CPVC a 'riser' (because a 'main' use of said item is to connect lawn irrigation heads) i needed one to go downwards, so, naturally i asked for a 1/2x4 'dropper' see what i mean? it is still a nipple, regardless of what the box stores wish to call it it is still a diaphragm type compression tank, which is used to contain the expansion of the entrained air to avoid (S)PRV release Edited 1 times. |
Please note:
- Inappropriate messages or blatant advertising will be deleted. We cannot be held responsible for bad or inadequate advice.
- Plbg.com has no control over external content that may be linked to from messages posted here. Please follow external links with caution.
- Plbg.com is strictly for the exchange of plumbing related advice and NOT to ask about pricing/costs, nor where to find a product (try Google), nor how to operate or promote a business, nor for ethics (law) and the like questions.
- Plbg.com is also not a place to ask radiant heating (try HeatingHelp.com), electrical or even general construction type questions. We are exclusively for plumbing questions.
Special thanks to our sponsor:
to FAQ's - to popular subjects - to plumbing books - to Tankless 101 - to plumbing history - to helping charities - to contact us
We lay our expansion tanks on their side, right on the heater. We pipe in a tee a few inches above the cold nipple and screw the tank right into it. Other #2 used often around here is to mount the tank upside down right above the tee and use the bull of the tee to aim towards the back wall, turn up just past the tank, install your valve and pipe to the wall as your normally would.Hey Terry, what'd you use for the T&P drain?
Almost looks like a flexible gas line? At first I thought it was a s.s.
Braided line. No reduction in pipe size there is there? To clear up a few things posted above. According to Amtrol (manucafturer of thermal expansion tanks) they are required to be installed in the verical position. Although the instructions show the thermal expansion tank being installed on the cold water side, they are rated for upto 150 degrees and there is nothing in the instructions or warranty that prohibits them from being installed on the hot water side. I spoke to tech support at Amtrol and verified this information. Unless by local code there is no reason they cannot be installed on the hot side.
Here is a link to the instructions Hope this helps.Paul.