I have an issue where the upstairs water pressure, specifically the shower, drops greatly (~in half) when a tap is openned downstairs. This is most noticed when the sprinklers come on or the garden hose is used. The biggest issues is that the water temp in the shower turns scalding when this happens.
I have a 1″ main from the city and a pressure regulator that feeds a 3/4″ line into the house. A 1/2″ line then feeds the entire upstairs.
Question -Can I resolve my issue by splitting the 1″ main into two 3/4″ lines, each with a separate regulator: one to feed the downstairs and one to feed the upstairs? The current pressure on the low side of the regulator is 75lbs. Not sure what the pressure is on the main side.
You should install a pressure balance shower valve. Check the inlet pressure to the regulator, you need to know this pressure. If the pressures are close under a flow such as hose running then your pressure reg. should be ok, If not then your reg. or If you have a strainer could be clogged partly. You could repipe your hose outlets @ your sprinkler system to their own circuit @ install a regulator for this circuit @ set this at a lower operating pressure, or if you could install a check valve with ten pound spring, this way you would have ten pounds more pressure available to your indoor water piping than outdoor. This is one idea but I would try to find a qualified plumber to look at your needs on this.