Using a 1" PRV on a residence, dual-pressure system

[plasmech]

3.5-year-old 3500 square foot residence, 2.5 bath

I’m having an issue with my Watts LF25AUBZ3 (3/4”) PRV causing excessive pressure fall at relatively low flow rates. The service side is a steady 75 PSI. I have the house side set to 50 PSI static. When I flow 10 GPM, the house side drops to 25 PSI. The supply side stays at 75 PSI, indicating that I do not have a supply problem.

My setup is shown in the pic below.

I checked the strainer in the PRV, it is clean.

This is my second LF25AUBZ3 in only 3 years. The first one was unable to hold pressure even in a static state.

I am thinking about reconfiguring the setup to accommodate a Zurn 500XL3, which I suspect is a significantly higher quality PRV. On paper, its pressure fall is much less than that of the Watts. I am also thinking about switching to a dual-pressure system: 50 PSI regulated for the house, 75 PSI unregulated for the hose bibs.

I would adapt the current ¾” supply to 1” and install a 1” LF7R backflow preventer. I would then do a 1” + ¾” branch. 1” for the Zurn LF25AUBZ3 (the smallest size it comes in) and ¾” for the hose bib manifold.

Note that my Watts LF7R backflow preventer is currently downstream of my PRV. It would be moved upstream.

Does this all sound like a good idea? Am I missing anything?

Feedback and/or telling me I’m crazy is welcome.

Thanks.

 

[Twowaxhack]

If you have 75 psi I wouldn’t use a PRV.

 

[breplum]

The flow chart on the 25AUB is low. The higher flow prv used to be U5B (just looked, those beasts are $547. !)
I only install double union PRVs bc it makes replacing a dream.
If I was installing where we want higher flow would definitely go with a 1", competitive valve.
But, Twowax said it all...at 75psi, YOU DO NOT NEED A PRV.
AND WHY THE CHECK VALVE AT ALL? With a check valve you then need to have an expansion tank at WHs

 

[plasmech]

Thanks for the replies.

I've had others tell me that 75 PSI does not warrant a PRV.

I guess my question is: how do I know that the service pressure will never go above 75 PSI?

The backflow preventer is required by code in my area.

I could remove it but might have to reinstall it if I ever go to sell the house.

Does a backflow preventer hurt anything?

 

[breplum]

You might search for a flow chart (rate of flow) for your particular backflow device.
They Definitely have psi-related correlation to flow.
Clean setup and pretty photo btw.

 

[molson]

Thanks for the replies.

I've had others tell me that 75 PSI does not warrant a PRV.

I guess my question is: how do I know that the service pressure will never go above 75 PSI?

The backflow preventer is required by code in my area.

I could remove it but might have to reinstall it if I ever go to sell the house.

Does a backflow preventer hurt anything?

Interesting thread. Plasmech where are you located in PA curiously? We can send you a Caleffi PRV to swap out. It's double union like BREPLUM suggested. Keep us posted in return. [email protected] to discuss

 

[Hamberg]

Seriously, clean set-up! Are you in the Philly area? Foil-faced insulation looks like a Toll Bros house (Bucks County!?)

 

[Twowaxhack]

I like everything except the stainless cinch clamps and the propress. I don’t like PRV’s unless absolutely needed.

I like that shiney stuff

 

[plasmech]

I like everything except the stainless cinch clamps and the propress. I don’t like PRV’s unless absolutely needed.

I like that shiney stuff

What's wrong with the cinch clamps on the PEX?

(Asking because I don't know).

Thanks.

 

[plasmech]

Seriously, clean set-up! Are you in the Philly area? Foil-faced insulation looks like a Toll Bros house (Bucks County!?)

I'm in 19342.

It's not a Toll Brothers house.

I hate that insulation. Having insulation on your basement walls is like having no basement walls. You can't use the walls for anything useful like handing shelves, electrical conduit, etc.

 

[Twowaxhack]

What's wrong with the cinch clamps on the PEX?

(Asking because I don't know).

Thanks.

They’re inferior to the copper rings from what I’ve see in the field.

I’ve seen them break.

 

[plasmech]

They’re inferior to the copper rings from what I’ve see in the field.

I’ve seen them break.

Ugh. I have an entire house full of them.

Are you seeing them break on installation, or are you finding broken ones when you get the flood call?

And how often?

Thanks.

 

[Twowaxhack]

Ugh. I have an entire house full of them.

Are you seeing them break on installation, or are you finding broken ones when you get the flood call?

And how often?

Thanks.

Just here and there. I’m not sure of the brand clamps or why they broke.

It’s a service call, water damage present.

 

[Mitchell-DIY-Guy]

I hate that insulation. Having insulation on your basement walls is like having no basement walls. You can't use the walls for anything useful like handing shelves, electrical conduit, etc.

For a builder to insulate basement walls with anything is pretty remarkable. Must be local code since they would never do it out of the kindness of their heart.

You may not realize it but it’s making your flooring on the first floor more comfortable in the winter, and stabilizing temperature swings in the basement and contributing to preventing heat stratification in the home.

You could, at your leisure, replace it in parts or all with foil faced rigid foam board. A 2” 4x8 runs under $50. With that on the walls, it’s a lot easier to use your basement.

 

[plasmech]

Is ProPress a good system?

That's what I'm planning on using.

Thanks.

 

[Twowaxhack]

Is ProPress a good system?

That's what I'm planning on using.

Thanks.

It’s fine but it’s not as good as solder joints.

Why buy the best pipe then use orings to seal it ? Seems like a great idea for other peoples plumbing but not my personal plumbing.