TP wrote:

I want to install a new shower valve with multiple sprays. Someone
mentioned I should install a vacuum breaker while redoing all the plumbing.
How is one to install a vacuum beaker and is it needed?

Thanks

Unless the shower is to have a flexible hose
wand which could possibly be left lying in the
shower pan (waste water), there would be no
reason for a vacuum breaker.

The breaker prevents waste water from being
siphoned back into the water supply lines
(such as during a momentary loss of pressure).

They are useful for protecting things like
lawn sprinkler/irrigating systems and garden
hoses where the poisons used could be sucked
back into the water system.

Jim