Re: Home expansion tank - water hammers

Wantomeeto wrote:
> 
> Hi -
> 
> I don't know if it is code or not but we have a 5 gallon expansion tank
> plumbed into our hot water line upstream of the HWT.  I think it's purpose
> is to prevent the pressure relief valve on the water heater from operating
> too frequently.   As a side benefit I assumed it also absorbed water hammers
> but I am wrong.
> 
> I would prefer to remove it completely from my system and instead install a
> water hammer supressor.  Not sure if those actually work (any feedback would
> be apprec.)  The expansion tank just has to be a code item.  Any suggestions
> on where I should look for this code?  I think the tank is useless and want
> to save $50 if I can.  Any help apprec.

The tank was likely installed because it is needed.  You're correct 
about its purpose being to absorb high pressure in the tank due to
(thermal) expansion.  Leave it there.

If you have a specific appliance causing hammer, put a hammer arrestor
as close to the appliance as possible.  To be effective, the device
must be near the origin of the shock wave.
http://www.watts-intelliflow.com/hammer5.htm

Jim