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# Thread: split line of 2" copper water line from city

1. ## split line of 2" copper water line from city

Like below drawing, city water flows in 2” copper pipe with 45psi, and then it splits into another 2” line ( (a) line ) and continue to run (b) line.
There is 2” Ball Valve in the middle of (A) line.

What happens if the ball valve in (A) line closed half(50%)?
1) (B) line gets any benefit? More pressure? Or more flow?
Or,
2) (B) line’s water volume and pressure remains the same?

Thanks much,

--Novice-man

2. It all depends on flow. If the flow in A was such that the dynamic pressure at the split point was being dropped by flow in the main supply, the reducing the flow to A would cause the dynamic pressure at the split point to be higher, so B would flow more.

3. ## pipe

That is like asking, "How high is up?" Your answer depends on the dynamics of the system, how much water is available, how much is being used at both A & B when the valve is open, if A is using its maximum amount when the valve is open and if more is needed at B, and if the pipe to B is able to carry more volume. And, a ball valve should not be adjusted to anything other than full open or fully closed to avoid destructive turbulence.

4. Originally Posted by hj
That is like asking, "How high is up?" Your answer depends on the dynamics of the system, how much water is available, how much is being used at both A & B when the valve is open, if A is using its maximum amount when the valve is open and if more is needed at B, and if the pipe to B is able to carry more volume. And, a ball valve should not be adjusted to anything other than full open or fully closed to avoid destructive turbulence.
what is "destructive turbulence"?

5. ## Copper pipe split

You know like in the "GRAND CANYON " !

When you have a ball valve in less then fully open or closed

it disturbs the water steam and causes erosion to the inside the pipes and

fittings ! !

6. Originally Posted by MACPLUMB 777
You know like in the "GRAND CANYON " !

When you have a ball valve in less then fully open or closed

it disturbs the water steam and causes erosion to the inside the pipes and

fittings ! !
just erosion?
if 45 degree close, is this mean 50% close, right?

7. A ball valve should be either open or closed...anything in between can cause the pipes to literally wear out from the inside.

A ball valve should be either open or closed...anything in between can cause the pipes to literally wear out from the inside.
Then, gate valve is OK?

9. no, gate valves also should be all open or all closed

10. Originally Posted by msgale
no, gate valves also should be all open or all closed

1) how long can I use copper pipe before it destruct and erode make a hole or leak? ( if I use a ball-valve)

2) what kind of valve can I use to close 50%?

Thanks,

11. A globe valve. Flow is redirected from a chamber in the lower part of the valve, up and through the seat assembly and finally out the top chamber. That action keeps the flow from constantly wearing against one portion of the valve or pipe.

www.nibco.com

12. Why do you want to throttle the water supply so badly? A properly designed system you should not have a need to do this.

13. ## valve

quote; just erosion?
if 45 degree close, is this mean 50% close, right?

If I could understand what you are asking, I might be able to answer the question.

14. Originally Posted by hj
quote; just erosion?
if 45 degree close, is this mean 50% close, right?

If I could understand what you are asking, I might be able to answer the question.

1) ball valve causes only "erosion" issue? how bad it is? and how long can the pipe hold the erosion before corrupt? and how many years can I use the pipe? and how will happens eventually, e.g. hole? or leaking?

2) IF TURN HALF(IOW, MIDDLE BETWEEN 'FULL OPEN' AND 'FULL CLOSE', LIKE ABOVE DRAWING), IT CLOSES 50% OF WATER FLOW, RIGHT?

15. It depends on how high the flow rate is through the system. It's sort of like asking how high is up...depends on your reference point. As noted, neither a gate valve nor a ball valve are designed or intended to throttle flow - it's either all or nothing.

Use the right tool for the job..it's like using pliers verses a properly sized wrench...it depends on whether you'll ruin it or not, and if you do it often enough, you certainly will.

How wet do you get when you put your finger over the end of a hose? Partially closing a gate valve or ball valve increases the flow rate and momentarily the pressure.

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