Water Shutoffs: Knob vs Lever

[Doug Kanter]

My kitchen sink is at the end of the water supply run. Bath tub comes first, then bathroom sink, and finally, the kitchen. The water pressure in the bathroom is fine, but it's bordering on anemic at the kitchen faucet. It's a brand new Moen, and the same problem existed before I installed the faucet. I wonder if the reason is that in the supply line, after the bathroom but before the kitchen, there are shutoffs - the lever type that you turn 90 degrees to operate. Does that type have any sort of bad reputation for messing with pressure, as compared to the knob type that requires several revolutions to open or close?

[Abe]

The type of shutoff has no bearing on pressure.

[Doug Kanter]

OK. Thinking just of the cold water for the moment, the supply line is a straight run from the meter to the kitchen, with branches picked off about

20 feet back for the bathroom. It takes a 90 degree bend upward to the kitchen sink one floor above. When I replaced the faucet, I also replaced the flexible supply lines because they looked worn, but the problem remains. What's your next guess?

[Rich256]

Can the shutoff be taken apart? If so I would pull out the stem and take a look at it.

You could do a test at that point too. Someone hold a pail under it while turning on the water supply. I would really expect the lever type to give better flow but there could be something stuck inside.

[Pete C.]

It is true that the type of valve has no bearing on the water pressure, however it does have a bearing on flow rate which most people perceive as pressure.

The ball valve type (1/4 turn lever, or some new knob types) provide a straight through flow path that provides far less flow resistance than the multi turn knob type where the water has to take typically two 90 degree turns. In short the 1/4 turn ball valve type are superior to the multi turn type.

Pete C.

[Sev]

Didn't you just say 1 floor above? Perhaps that is the issue, if your pressure at meter/ regulator is very low. If it's ok, I guess I'd agree that you may have obstruction in flow.

[Phil Munro]

[Doug Kanter]

No. Brand new faucet. The problem existed from the moment it was installed, and the previous faucet had the same problem. The screen has been checked in the new one.

[PipeDown]

Half true.

Regardless of the amount of valve opening, Static pressure will be equal at both sides of the valve when no water is flowing.

While the water is running, the Dynamic water pressure will be reduced by the amount the valve is closed (impedance).

It's just like voltage across and current through a resistor.

Multi turn valves allow more control over dynamic pressure but have reliability issues with being turned all the way off. Ball valves (lever or knob) turn all the way off and on better but have less control in the middle

[Toller]

The valve does not affect the static pressure, but it sure does the dynamic pressure. That is why the flow rate is lower. People's preceptions are accurate here.

A full bore ball valve is better as you say; but a cheaper reduced ball valve is probably inferior.

[Doug Kanter]

All I know is that if I stick a watering can under that faucet, it takes twice as long to fill up, compared to using any other faucet in the house. :-)

[Lena]

I'd suspect that there might be a flow limiting washer on the faucet. I've seem them just above the aerator, a metal washer with a small hole in it, that limits how fast water can come out. I throw them away. I like to be the one that controls the flow of water, not some pencil necked geek in a government office regulating what faucet manufacturers must add to their products.

Lena

[PipeDown]

Assuming the valve and faucet are good then you have a restriction in the pipe to the sink. Do you have galvinized steel pipes? I would expect this to happen in that kind of plumbing eventually.

The 90 deg elbows seem to form the most rust inside from what I have seen replacing my pipes for repairs. >50% rust fill in is typical of my old pipes. Fortunatrely this house hasn't had any pinhole leaks yet. I do have an interesting jackhammer like cavitation going on in a Tee near my kitchen sink when I turn the hot on too much.

[Doug Kanter]

All copper, from meter to sink, except for a new set of flexible hoses for the last 18". I have steel drain pipes for the bathroom. I don't even wanna talk about those - I already have a headache. :)

[PipeDown]

I'm stumped unless the new hoses are the "flood safe" kind. In which case they may have tripped and you need to briefly remove them from the valve to reset.

[hallerb]

Newer faucets are required by law to limit MAX flow. I would call moen and ask them. There MIGHT be a quick easy fix like removing a flow restrictor in a shower head.

Beyond that try connecting a temp hose at the sink bypassing the faucet and check that.

some of those flexible hoses have a very smaii inside dioameter, that may be contribuiting

[Doug Kanter]

Side note: After my divorce, I was in an apartment for 2-1/2 years. It drove me crazy. I kept telling friends "I gotta get outta here - I need a garden, and I like working on my house!" Be careful what you ask for, ya know?

[Tony Hwang]

Hi, City water? Well water? In my house regulated pressure is 60 psi. No such problem. Wonder why you're suspecting the shut off valve? Maybe you don't have high enough pressure to begin with.

[Doug Kanter]

City water. 120 lbs before regulator, 55 after.

[Lena]

Just had to replace one of those 'flood safe" connectors with another non-flood safe flexible connectors on the toilet. It seems like it got a bit of dirt in it, caused some water hammering, and then slammed shut. I was surprised how fast the toilet filled with the regular flex connector. Apparently, the flood safe valve, or the washers with small holes that came with it, limited the rate of flow.

Lena