Phisherman wrote:
I installed an expansion water tank when GE stated the warranty on the
water heater is void without one. So, I charge the tank to 40psi as
stated and installed it fairly easily. I'm on city water at about
70psi. I noticed now that when the water is turned on anywhere in the
house, that a burst of water comes out the first couple seconds. I
notice this most on the kitchen vegetable sprayer and both showers. I
suppose this is supposed to happen, but it does not explain why.
Expansion tanks are supposed to help preserve water appliances.

An expansion tank isn't a regulator and is only part of what you need
for a proper design when you have high water pressure. Installing a
regulator will produce a good result.