Looking to install a PRV

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TCP

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Hey so I've been in my home a little over a year and been meaning to put in a PRV. I have street pressure of 80 lbs and I think it spikes sometimes to 90 or so. I left a pressure gauge with the needle that shows the maximum pressure it reached on a hose bib overnight. I dont have much room to do it in the street so I plan to do it where it enters the home. I drew up a sketch with a bypass in case it needs to be changed in the future. One question I had is if I need a BFP when installing a PRV; can it function alone? I already have the expansion tank for the hot water heater installed. Am I missing anything? What is a good pressure to set the PRV to? Any recommendation for a brand of PRV? Thanks

prv.JPG
 

Reach4

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One question I had is if I need a BFP when installing a PRV; can it function alone? I already have the expansion tank for the hot water heater installed. Am I missing anything? What is a good pressure to set the PRV to?
I am not a plumber.
Your PRV with metering and bypass are more through than the usual install.

I don't know what a BPF , but your thermal expansion tank, presuming it is sized properly, should be enough. Some PRVs are "bypass" type, which will allow passage back to the input if the output pressure rises sufficiently above the input pressure. With your thermal expansion tank, that feature should not be needed.

The brands that I remember are Wilkins, Watts, and Cash-Acme. I don't know which is better, but maybe those names will help you in your search. https://terrylove.com/forums/index.php?threads/can-you-ros-recommend-a-good-prv.59661
https://terrylove.com/forums/index.php?threads/pressure-reducing-valve-replacement.69527/
https://terrylove.com/forums/index....-pressure-drop-when-one-fixture-is-open.68303

may offer some info.

One characteristic is the pressure can drop with increasing flow. You can find data and graphs that a larger PRV can usually have less drop at a given GPM. I am not a plumber. It is possible to use a bigger PRV than the rest of your piping.
 

Sluggo

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1. I wouldn't go to the trouble of installing a bypass as you have shutoff valves, and it doesn't take much work to replace a PRV, especially if you have unions installed. Rebuild kits are also available, also don't take much time, and can be done with the PRV in place if you have clearance to get to all the bolts and removable pieces. Besides, if the bypass valve gets leaky, it would defeat the ability of the PRV to control pressure.
2. if possible exclude outdoor spigots from the PRV system, as it's good to have full pressure for your hoses outside.
3. Will the location for the PRV have adequate freeze protection?
 

Jadnashua

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When a BFP (back flow preventer) is installed, unless you have an irrigation system, it is usually part of the water utility's equipment ahead of your entry, or part of their meter. Local codes might dictate you add one when remodeling, though, so you should check. If you do have an irrigation system, you typically are required to have the BFP tested annually as well.
 

FullySprinklered

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Best case scenario on the PRV is to have a union on either side of the device. Some come with a single union with the option of screwing the valve on the other side which has a 3/4 male adapter. It's ok unless it's up against a wall or joist and won't spin all the way around. Not the end of the world, but it's more work.

Down the road, threads on the unions differ according to brand. Apollo and Watts are not interchangeable when you go to swap out the old device. Again, doable but a little more work. The bypass thing isn't wrong by any means but it's like carrying two spare tires. The main shut off is really all you will need.
 

TCP

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Thanks for all the replies. I do have a BFP but its on the irrigation side. So the supply coming from the street branches off to the irrigation and to the house. The side for the sprinklers has a BFP but it also has the same 80-90 psi which is high for a sprinkler system. I do get some misting on some heads but I'm more concerned about all the new fixtures in my home.
The two reasons why I wanted a bypass in the station was two fold. One for obvious reasons if for some reason something goes wrong and I cant find a replacement right away I can still be operational. Second reason was I wasnt sure if a PRV also acted as a BFP because my expansion tank is only rated for 60psi for a 50gal hot water tank. So in the event that the PRV would pass pressure the tank would not be sufficient enough if the water could not backflow. So then I could just open the bypass and have the pressure shoot back to 80+ and it would also relieve any excess pressure back to the street.
 
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Jadnashua

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Any ET for potable water (maybe not one for hydronic heating - some can be used for either, but not all) should be designed for up to 80psi. For maximum longevity, the ET should be precharged to your static pressure (or, if you add a PRV, the value you've set it to). That puts the bladder at its neutral position, minimizing how much it needs to flex, which affects longevity.
 
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