How do you change pressure gauge in sand filter?

Turn off the power - a switch that you have to turn manually - the time clock but make sure that it will not come on while you are working in the filter or piece of equipment. Or turn off the circuit breaker.

Take out the bad gage, use Teflon tape on the threads of the new gage - a couple of turns of teflon - insert new gage into hole and tighten SNUGLY. Do not over tighten. Test and then return the timer, switch or circuit breaker to normal run position.