Delta Rough in Valve Causing Low Pressure?

[Junior1s]

New member,
I live on a well and have great water pressure. I installed a new Kinetico water softener and pressure tank with all 1" copper pipes. Then it transitions to 3/4" copper throughout the house. My pressure switch is a 40/60psi. The only location my water pressure is low is the shower head in the bathroom. With no cartridge valve installed in the rough in valve, the water literally flows out of the rough in valve like a hydrant and hits the opposite wall that is 5 feet away.

The shower head is high flow with no restrictor. I have a 17 series Delta shower faucet with separate temperature and water flow handles. My rough in valve is a Delta with no water stop valves. It is a simple 4 way.

I will get a delta rough in plug to bypass the cartridge valve and test the water pressure at the shower head. Until then I have a question.

Due to the design of the Delta rough in valve it seems the water going to the shower needs to pass through a smaller opening than when the water passes through tub port.

What is the purpose of the tub port of the rough in valve being left unrestricted, but the shower port seems to make the water flow partially restricted?

I have seen posts suggesting to invert the rough in valve during installation to allow more water flow to the shower head.
Thanks!

 

[Jeff H Young]

Ive never attemopted to invert the valve or looked at the trim to see if that works. its possible thats a good idea but I cant confirm . sounds like a good trick but sure wouldnt want to find out the hardway
The desighn is for tub /shower diverter function when tub runs we dont wantwater coming out shower at same time.
Delta valves at least the older ones and possibly other brands are known to plug up and be close to impossible to fix by blowing air etc through them. just had one a few monthes ago so the passage is prone to blockage

 

[Sponsor]

 

[John Gayewski]

The valve is made that way so when you want a bath and run bath water you don't get water coming through the shower head.

 

[Junior1s]

Thanks for the replies and clarification on the design of the Delta rough in valve. I just received the Delta rough in valve pressure test cap today. I will install it and see the type of pressure I get at the shower head. This will tell me exactly where my water pressure is dropping.

I will post my findings soon.

Thanks!

 

[John Gayewski]

Thanks for the replies and clarification on the design of the Delta rough in valve. I just received the Delta rough in valve pressure test cap today. I will install it and see the type of pressure I get at the shower head. This will tell me exactly where my water pressure is dropping.

I will post my findings soon.

Thanks!

The pressure is gonna be the same with no flow everywhere with no flow.

You be better off grabbing a bucket and measuring the flow rate from different places

 

[Junior1s]

I may not have been clear in what I want to do and why. The current pressure with the Delta 17 series valve is ok. I could live with it but I feel it could be better by around 20 to 25 percent. I have the newer style Delta rough in valve since 2010 with the two "V" cut outs to accept the newer style Delta cartridges. The same 3/4" copper pipe feeds the bathroom sink and the shower. They are 5 feet apart. The pressure coming out of the bathroom sink is very high. I literally cannot open the the hot and cold handles more than a 1/4 turn, because the pressure is so high.

What I want to do is remove the shower faucet cartridge from the rough in valve and place the test cap. Then turn on the water and see what kind of pressure I get at the shower head. I am anticipating much more flow since the cartridge is removed. If this is the case, this tells me I do have good water pressure at the rough in valve and that maybe the Delta cartridge I have does not flow well.

I'm sure different rough in valves will have better flow than others. Any cartridge is going to restrict flow, so having a rough in valve with a higher flow rate would help improve whatever restriction is present in the cartridge. I'm just curious what my water pressure will be with the cartridge removed. Maybe this will tell me something.

 

[John Gayewski]

I may not have been clear in what I want to do and why. The current pressure with the Delta 17 series valve is ok. I could live with it but I feel it could be better by around 20 to 25 percent. I have the newer style Delta rough in valve since 2010 with the two "V" cut outs to accept the newer style Delta cartridges. The same 3/4" copper pipe feeds the bathroom sink and the shower. They are 5 feet apart. The pressure coming out of the bathroom sink is very high. I literally cannot open the the hot and cold handles more than a 1/4 turn, because the pressure is so high.

What I want to do is remove the shower faucet cartridge from the rough in valve and place the test cap. Then turn on the water and see what kind of pressure I get at the shower head. I am anticipating much more flow since the cartridge is removed. If this is the case, this tells me I do have good water pressure at the rough in valve and that maybe the Delta cartridge I have does not flow well.

I'm sure different rough in valves will have better flow than others. Any cartridge is going to restrict flow, so having a rough in valve with a higher flow rate would help improve whatever restriction is present in the cartridge. I'm just curious what my water pressure will be with the cartridge removed. Maybe this will tell me something.

The pressure will be the same at the shower head, at the toilet, at the lav, cartridge in, cartridge out. The same. Only dynamic pressure would change. Unless you have a semi elaborate setup to measure this, a bucket will tell you more.

 

[Jeff H Young]

I may not have been clear in what I want to do and why. The current pressure with the Delta 17 series valve is ok. I could live with it but I feel it could be better by around 20 to 25 percent. I have the newer style Delta rough in valve since 2010 with the two "V" cut outs to accept the newer style Delta cartridges. The same 3/4" copper pipe feeds the bathroom sink and the shower. They are 5 feet apart. The pressure coming out of the bathroom sink is very high. I literally cannot open the the hot and cold handles more than a 1/4 turn, because the pressure is so high.

What I want to do is remove the shower faucet cartridge from the rough in valve and place the test cap. Then turn on the water and see what kind of pressure I get at the shower head. I am anticipating much more flow since the cartridge is removed. If this is the case, this tells me I do have good water pressure at the rough in valve and that maybe the Delta cartridge I have does not flow well.

I'm sure different rough in valves will have better flow than others. Any cartridge is going to restrict flow, so having a rough in valve with a higher flow rate would help improve whatever restriction is present in the cartridge. I'm just curious what my water pressure will be with the cartridge removed. Maybe this will tell me something.

I follow you but knowing how much your valve flows with a cartridge removed is pretty useless information. the information is available on a chart someone uploaded it the other day but the cartridge reduces flow absolutely put your cartridge in and run water into a bucket . I thought you clearly had a plan to use the bottom port for the shower by turning it upside down ? you could just pipe it from the bottom . assuming you are just going to have a shower only and again I have no idea if youll get more water flow sounds like a bit more might be available though

 

[Junior1s]

I have competed my testing. I tested water flow as others have suggested. Before every test I cycled my well water pump to 40psi and then back to 60psi. So all test were started with a water pressure of 60psi. I filled a 5 gallon bucket for one minute and then measured how much water was in the bucket in gallons.

I have a Delta 17 series faucet with separate volume and temperature controls. My rough in valve is a Delta new style with 1/2" fittings, tub and shower only with no stops. My shower head is an 8" rain shower head with restrictor removed.

Below are the results.

TEST 1
Delta cartridge installed. Water flow at shower head.
3.0 gallons per minute

TEST 2
Delta cartridge installed. Water flow, at shower arm.
3.22 gallons per minute

TEST 3
Delta cartridge NOT installed. Water flow, at shower arm.
4.5 gallons per minute

TEST 4
Delta cartridge NOT installed. Water flow, at shower head.
4.1 gallons per minute

The results were as I expected. Much more flow without the cartridge valve installed. I didn't expect to have such high water flow (3.0 GPM) at my 8" rain fall shower head with the rough in cartridge valve installed. This tells my hard work of replacing all my 1/2" copper to 3/4" was worth it.

While my flow is very good, it is still being restricted by the valve cartridge which I expected.

I wonder if Delta makes higher flow combinations of cartridge and rough in valves. Although I can't complain with what I have.

 

[John Gayewski]

I have competed my testing. I tested water flow as others have suggested. Before every test I cycled my well water pump to 40psi and then back to 60psi. So all test were started with a water pressure of 60psi. I filled a 5 gallon bucket for one minute and then measured how much water was in the bucket in gallons.

I have a Delta 17 series faucet with separate volume and temperature controls. My rough in valve is a Delta new style with 1/2" fittings, tub and shower only with no stops. My shower head is an 8" rain shower head with restrictor removed.

Below are the results.

TEST 1
Delta cartridge installed. Water flow at shower head.
3.0 gallons per minute

TEST 2
Delta cartridge installed. Water flow, at shower arm.
3.22 gallons per minute

TEST 3
Delta cartridge NOT installed. Water flow, at shower arm.
4.5 gallons per minute

TEST 4
Delta cartridge NOT installed. Water flow, at shower head.
4.1 gallons per minute

The results were as I expected. Much more flow without the cartridge valve installed. I didn't expect to have such high water flow (3.0 GPM) at my 8" rain fall shower head with the rough in cartridge valve installed. This tells my hard work of replacing all my 1/2" copper to 3/4" was worth it.

While my flow is very good, it is still being restricted by the valve cartridge which I expected.

I wonder if Delta makes higher flow combinations of cartridge and rough in valves. Although I can't complain with what I have.

The max legal flow is 2.5 gal per min. I'm gonna doubt they make anything designed to give you more than what you have.

 

[Tuttles Revenge]

Delta makes what they call a High Flow Valve. It doesn't have a tub port.. so basically its the same as inverting the tub/shower universal valve to get tub flow at the shower.

The 17series cartridges are their highest flow at something between 7-9gpm

But as John points out manufacturers are held to certain standards and installers must adhere to local codes.

 

[Jeff H Young]

run bigger pipe and go valve shopping. if you cant accept the results