Hydraulics in an expansion tank

Jim_16

Hey Guys,
Here's the setup. A diaphram style expansionn tank is installed on a residential heating system. It is directly off of the top of the piping so that air may fill the tank clear down into the 3/4 inch pipe cming off the main. The system is set at 12 psig. When the system is in the heating cycle. Is it harder to get the expanded water into the tank ? Why ,and is there any mathmatical proof ? It is located between the boiler and the air seperator. Everything else appears to be piped correctly. I'll check back in this evening after work.

Thanks Jim

[Deleted User]

Flip

the tank over. It's upside down, and you've got air wherer you're only supposed to have water.

ME

[Deleted User]

Flip

the tank over. It's upside down, and you've got air where you're only supposed to have water.

ME

bill clinton_3

x tank

Sorry, this doesn't make sense. When the expansion tank is installed, that 12 psi pushes the bladder all the way to the 3/4" opening. The bladder stays there until water pressure exceeds 12 psi. What this means is you got no air on the underside of that bladder. AND if you had some, the system air elimination should get rid of it purty dang quick.

Bill

Unknown

here's the scoop....

nothing about upside down, though.

http://www.amtrol.com/website/content.nsf


Frequently Asked Questions About Extrol Expansion Tanks


Q. What should the precharge be in the Extrol tank?
A. The precharge pressure, in the Extrol tank should be set to the
fill pressure of the heating system. This should be done before the
tank is installed on the system.
Q. Do I need to empty all of the water out of the Extrol tank to check the
precharge pressure when the tank is already installed?
A. Yes, you will need to either isolate the tank, then remove it or drain the
system to get all the water out the tank before you can correctly check the
precharge pressure.
Q. How can I tell if the Extrol tank has failed?
A. First the relief valve on your boiler may open and spill water on the floor.If this
happens let a little air out of the charging valve on the Extrol tank. If you get
water coming out, the diaphragm has broken and the tank would need to be
replaced.
Q. Can the Extrol tank be installed horizontally?
A. No.
Q. Is Ethylene or Propylene glycol compatible with the Extrol tank diaphragm?
A. Yes, it is compatible with any percentage of Ethylene or Propylene glycol.
Q. Can the Fill-Trol valve be used on an Extrol tank?
A. No, the Extrol tank doesn't have an actuator to accommodate the Fill-Trol
valve and the threaded connection is not compatible with the Fill-Trol valve.
Q. Why can't the Extrol tank be installed on a dead end loop above the boiler?
A. Air can get trapped in the dead end portion of the closed loop and the Extrol tank
will rust.
Q. Where should the Extrol tank be installed on the system?
A. The Extrol tank should be installed on the suction side of the circulator.
Q. What information do I need to size an Extrol tank?
A. 1. Total System Volume.
2. System Liquid.
3. Minimum Fill Temperature.
4. Maximum Operating Temperature.
5. System Fill Pressure
6. Maximum Operating Pressure

Art Pittaway_2

Your right on, but,

the failed bladder check will work if you take note of where the fill/bleed valve is located. An inverted tank with the valve on top could need to be almost emptied to get a the water to the valve. Depends on the tank and installation location.
Nice job. Art

Art Pittaway_2

Your right on, but,

the failed bladder check will work if you take note of where the fill/bleed valve is located. An inverted tank with the valve on top could need to be almost emptied to get a the water to the valve. Depends on the tank and installation location.
Nice job. Art