Here's a unique one for you guys. Over the years I've installed five toilets/five bathrooms in this house. The last one left me scratching my head. The original copper pipe (1/2') that was used in this formal area had a few bends to it. I removed the bends, used Shark Bite fiddings and everything worked fine. However, (and it certainly could have been coincidental that the city kicked their presure up), the house presure spiked. It only spikes when you first turn any of the faucets on, and then settles down eight seconds later. You turn off the device, wait a minute or two, then turn it back on, and again it fires up to 75 pounds, eight seconds later it reduces to 55 pounds. There is no water presure regulator on this house. In thirty-two years it has been non-existant. The presure to the house is at 75 pounds.
So here are my questions:

1. Why does the presure drop after 8 seconds?
2. Should I be looking elsewhere for the house's sudden 8 second spike?
3. I'm going to add a presure regulator, has anyone had any negative issues with using Shark bite on 1'3/8's copper at the "regulator" point which is outside. (CA house, freezing is not a problem)

J

when you turn the water on, after 8 seconds the pressure drops. does the water actually slow down so much that you notice it? does this happen to your neighbors?
a pressure regulator will limit the house pressure to a maximum of whatever it is set at. it will not make up for any drop in pressure.
my thought is to check with the neighbors. if no one has the problem then we all gotta get out our sherlock holmes hat and start thinking..

Do you have well or city water?

None of the neighbors have this problem. However, they all have presure regulators built in to their homes.

City Water

from the internet...

: Yes, Section 608.2 Excessive Water Pressure of the Uniform Plumbing Code requires pressure regulators with a strainer whenever the static water pressure from the supply piping exceeds 80 psi.

as you can see, pressure regulator is not required below 80 PSI. s
this doesn't answer you problem ???

a drop in pressure like you refer to is usually indicative of debris blocking flow somewhere ??



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If its a flow resistance someplace, how do you go about isolating it?

J

trial and error

Can you be more specific. I know my way around plumbing, but I'm not a plumber.

I just don’t understand what exactly the problem is, even 55psi is plenty of pressure inside a home

Assuming your testing pressure on the cold side start getting readings from where the pipe enters the house if all good go to the next water supplied room see if results are the same this will require multiple cuts in to the cold and possibly hot piping

It may just be your piping is not sized properly to keep up with the flow rate of incoming pressure… maybe it’s time to install a prv

unless you have galvanized pipes in the house, debris doesn't get stuck nor build up in copper or plastic piping.
most times debris is the culprit, the debris is a chunk of rust that came in from the street main ??? so any shut off at the meter or the meter itself is the first place to look.
someone else had a good guess.. undersized piping could cause this ????

The presure in this house for the 34 years Ive been in has been steady. Whatever it is. It's never had a regulator, although all my neighbors do. My concern is that just resently the presure has jumped from 55 to 75 for approximately 8 seconds and then it drops down. Its still within the safe zone, but I'd like to find out why. Thirty-four years is a long time to draw a normal expectation. When that changes 20% it concerns me. At what point do I start getting concerned?

I'm going to change out the presure canister on my hot water heater and see if that is the culpret. I'll get back to evryone with my findings.

if you've had 55 PSI for so long then the expansion tank on the heater could be the problem.
with no PRV then any excess pressure built up by heating water just goes harmlessly back into the city main.

Add a ball valve in front of expansion tank. Then you can isolate it from the system for trouble shooting.

Good Evening,

I just wanted everyone to know. I changed out the Hot Water heater pressure canister and the problem was solved.

Thank you for all you help,

JayAey



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