Expansion tank dead end?

[whackit]

i just got flagged by an inspector (new guy in neighborhood) for having an expansion tank on a dead end line. It’s tee’d off the cold water supply to water heater and on a 2’ long dead end leg. Given the parameters (small room, big tank, location of backflow valve etc) there is really no other place to locate it. I have done this before in similar situations and not had a problem. Is there anything that prohibits this? I can’t find anything.

 

[Jadnashua]

When the WH runs, water will be pushed into the ET. When you later use some water, it will get pushed back out, so, it's not truly ever going to get stagnant. I haven't looked to see if there's a code limitation, but personally, it doesn't seem like a problem to me...any idea what code provision (was it stated in the inspection?) that applies?

 

[Sponsor]

 

[whackit]

He couldn't site any code reference. I have seen this plumbed this way a million times. I understand if it was on a 10' dead end but this is like 18".

 

[Reach4]

My search came up with people concerned about dead end for hydronic heating expansion tanks but not for regular water.