Expansion tank 1 or 2

[Kenandjoyce]

My home has 2 wh serviced by 1 inlet with a prv at the point where water enters the home. Each wh services half the home (ie west wh services west side and east wh services east side). Each wh has its own shut off valve. Calif plumbing code 608.2 say an expansion must be installed downstream of the prv. No other requirements except to follow manufacturers instructions. Manufacturer states same with no other requirements. Does that mean I can get by with 1 expansion tank for both wh or do I should I install 1 for each wh.
Thanks. Ken

[johnjh2o1]

If it's sized right one is all that's needed.

John

[hj]

Technically, the tank is supposed to go between the heater's shutoff valve and the heater, which would mean two tanks. One tank would absorb the pressure build up iIF the valves are not turned off.

[Hackneyplumbing]

Technically, the tank is supposed to go between the heater's shutoff valve and the heater, which would mean two tanks. One tank would absorb the pressure build up iIF the valves are not turned off.

Well technically the CONNECTION for the tank would need to go between the tank type water heater and the shut off valve. The physical location of the tank does not matter it just needs to be on the cold side and no stops or checks between the water heater and the expansion tank.

Since we are being technical.