What is the maximum water pressure that is allowed in residential or commercial buildings?

Hi Mitch357:

80 P.S.I is a maximum allowed residentially or commercially. After that plumbers are required to install pressure regulators (pressure reducing valves)... see image.

After installation most plumbers will set the pressure between 50-60 PSI maximum.

Let me know if you have questions...

MARK

What is considered normal water pressure? There really is no such thing as "normal" water pressure. Since water pressure is influenced by the elevation of the reservoir that serves your neighborhood versus the elevation of your water meter, water pressure varies from property to property. Water pressure in the District typically ranges from 45 - 125 psi; however, typical residential systems are designed to function best under a pressure of 40 - 60 psi. If the water pressure entering your home exceeds this level, you should install a pressure regulator in the line to reduce the pressure to an acceptable range. This protects your equipment and piping in your home from damage from excess force exerted by the water. Symptoms of high pressure include "clanging" or "rattling" of pipes that occur when a faucet, dishwasher, or washing machine shuts off; water heater pressure relief valve malfunctions, and reoccurring leaks. The symptom of low pressure is typically a noticeable reduction of flow.

In any of the areas I have lived in the water towers are always 100 feet high. Any idea why? Because the head pressure at 100 feet is 43.4 PSI The fall to the maim in the ground will add another few pounds and the pumping stations along the way will keep the mains pressured at 45 PSI. Some areas boost the pressure in the mains to reach outlaying areas so a pressure reducing valve must be installed at the point of use. Regards, Tom

I agree with posts above...

In my area, we are required to install Pressure Regulator when incoming water pressure exceeds 75 psi. Kohler claims the best operating pressure for their plumbing fixtures is around 55 psi.

As far as commercial plumbing goes: here, we install larger diameter pipes to compensate for high demand.