When are expansion tanks required?

[chicago]

I just did a condo with 50 gallon tank that had a 4.4 gallon expansion tank.

From what I gather these are to keep thermal expansion from tripping the TPR valve.

Does anyone know how it is determined when these are required.

Image Insert:

30.32 KB

[Jim Katen]

Originally posted by chicago

I just did a condo with 50 gallon tank that had a 4.4 gallon expansion tank.

From what I gather these are to keep thermal expansion from tripping the TPR valve.

Does anyone know how it is determined when these are required.

Generally, you use one of those things when the water service includes a pressure reducing valve. Particularly if the PRV lacks a bypass to allow excess pressure back to the street side.

- Jim Katen, Oregon

[chicago]

This was in the city and only a 3 story building which I believe had standard pressure with this being a duplex.

Far as I could tell there was no booster, but did not gain full access.

[John Dirks Jr]

In some areas they might be showing up in all new construction due to the 4 letter "C" word.

[John Dirks Jr]

I see the shutoff valve handle behind the ventpipe but I cant tell is it is on the cold side like it should be.

Also, since cold should be on the right, either the front of that tank is facing the wall or that expansion tank is connected to the wrong side. Shouldnt the expansion tank be on the hot side?

[chicago]

Since the humidifier line is on the same side I was rethinking this.You may be right.

[homnspector]

I see the humidifier line installed on the hot side fairly regularly, I think to reduce the evaporative cooling effect.

As far as the tanks, they are on all new construction here. May be a regional thing.

[John Dirks Jr]

The humidifier would work better with the line on the hot side. Was the thermostat facing out on that thing? if thats the case than something aint right. With the t stat/controll facing out, the cold should be on the right and the hot on the left.

[chicago]

False alarm ,but thanks for the heart attack as I am wrapping up the report.LOL

http://www.plumbersurplus.com/pdf/01203.pdf

[Jesse]

Wouldn't you need an expansion tank on the cold side if there's a backflow prevention device upstream?

[StevenT]

Any expansion tank that comes to my mind was on the cold side of boilers. I dont normally see them on hot water tanks. But if the x tank is at the cold water feed it could also accomondate both.

[chicago]

Yes... read the attached PDF.

It says cold side which is why I said, thanks for the heart attack.

It is easy to confuse with hot water furnace expansion tanks.

Glad some one gave it a thought though as They are not that common that I have seen.As far as the hot water tanks are concerned.

Steve I see you posted same time.

Is it boilers or furnaces.I think of boilers as steam.Hot water as furnace.

[StevenT]

I've always thought that a boiler heats water and a furnace heats air.

According to wikipedia, a furnace can heat air, or water (or other things too).

[chicago]

Yeah.. but the hot water never boils.

Your right though.

Hot Water (Hydronic) Heat

Water is heated in boiler, usually to between 160 and 180 degrees Fahrenheit. Pumps circulate the hot water through pipes in the building. This heated water warms radiators placed in the rooms. These radiators, in turn, warm the air in the room.

In some homes, pipes are buried in the concrete slab. This is type of system is called radiant heat.

Many people prefer (hydronic) hot water heat, because the radiators are small, the system typically quiet, and it can be easily divided into multiple zones. Hot water heat has made steam heat obsolete in homes and smaller buildings.

Cherry picked from here.

http://www.heimer.com/information/building_codes.html

[John Dirks Jr]

Originally posted by chicago

False alarm ,but thanks for the heart attack as I am wrapping up the report.LOL

http://www.plumbersurplus.com/pdf/01203.pdf

Sorry bout that...LOL[:-dunce]

[kurt]

Chicago now requires a tank on any new construction water heater install, and they also want to see a pan under the water heater.

The city (read union) also wants a pressure pump on any water inlet <1 1/2".

Of course, this being Chicago, approx. half the goofballs working don't know they're supposed to be doing this.

[chicago]

Kurt most of the work I get is new construction or rehab condo.

This is the first I have seen since inspecting.

Yes there was a pan also,but when was this enacted and how did you find out.

I feel dumb not reading about it.

[kurt]

My friend, do not EVER feel dumb about not knowing some aspect of the Chicago building/plumbing code.

This town is one goofy code stew; theres stuff @ the buildings dept., lots of stuff over @ DCAP (Dept. of Construction & Permits), and every mechanical trade has their own stuff, w/an amazing amount of it scattered over multiple documents.

I think they do it this way intentionally so no one can know anything.

Steve Hier (a great friend & inspector) and I make calls to various officials from time to time to figure this stuff out. Honestly, I'd have to check w/the guy in City Hall to find out when this was enacted, but it's been in place for a while. The pan ordinance has been in place for years, and it's only recently that folks started installing them.

Don't be surprised if some union plumber tells you I'm wrong; most of them are morons. (Sorry, but it's true.)

You know as well as I how inspections work in Chicago; the inspector is, first & foremost, a union brother. After that, they tend to be nephews of union officials. To top it off, there are few inspections, and they tend to be mere reviews of fees & paperwork, not actual inspections. Inspections do happen, but they are few and far between, and often politically motivated.

Harsh realities of the Big Dirty......

[Jesse]

Spoken like a true poet

[fqp25]

Speaking about Chicago Water Heaters & Inspectors, here are a couple more interesting facts; some water heaters require vacuum breakers. If they are bottom-fed or elevated above the fixture they are servicing. Also the pans can not be plastic they have to be galv or non-corrosive metal.

Does anyone know if they are enforcing heat traps on commercial water heaters?

Now speaking of the plumbing inspectors I have experience with in the past, well I can't say much because I don't want to get subpoenaed. I will say, they rarely buy their own breakfast & lunch...

[chicago]

I heard they have a new logo.

Blind man with a cane , but no tin cup,just an open hand palm up.lol.

Lets face it .If they did the job people in the public thought they did , we would not be needed.