Another water pressure problem in Colombia 1

[controlnovice]

Another water pressure problem in Colombia.

The lines in the picture represent 1/2 inch PVC pipe. Point B to C is about 50 meters. Point C is one user. The 4 branches leading 'down' are 4 other users along the line.

We don't know what the distance between A and B is. A is connected to a 1 inch line, to our knowledge...we haven't dug up anything yet.

The user at point C looses pressure often on an already very low pressure line. I don't have any pressure meters to know what we have, as we are in the mountains of Colombia. Of course, the 4 users at 1600m elevation have plenty of pressure and flow.

Since we don't know the length of pipe between A and B, I was considering changing the pipe between B and C from 1/2" to 1" to see if that would help user at point C. The problem with section A-B is it runs behind people's houses, through their yards. The piping was installed many years ago, and housing developed around it with no regard.

Is there any process/pressure issue with installing a 1" pvc pipe in section B-C without changing section A-B? Would it even help? Another option is to run a line parallel to the existing B-C section that only feeds user at point C.

______________________________________________________________________________
This is normally the space where people post something insightful.

 

[pierreick]

Hi,
I will run a parallel pipe from Point A to point C .By the way we have no indication about the distance between each point.
I've added a document to support your work.
Edit:
Another option is to add a buffer tank at point C together with a pump to supply water in accordance with flowrate and pressure requirement. This is very common in SE Asia.

Pierre

 

[1503-44]

Option 1. User at C needs a tank and booster pump.

Option 2. Double up A to C, or B to C, preferably with 2".
Cross-connect the new pipe to each existing user connection T.

1/2" pipe should only be used from a wall to a toilet, o wall to lavamano.
1" pipe from the street to the wall.

--Einstein gave the same test to students every year. When asked why he would do something like that, "Because the answers had changed."

 

[LittleInch]

God the lines are small.

If A to B cannot be replaced as it involves digging up other people's back yard for no vebefit to them, then your options are limited.

Replacing b to c with larger pipe will help but your restriction is really in A to B. If this is more than 5m, you will get only a marginal improvement.

A booster pump at B would help everyone out add a booster pump and separate line to C.

Or add a tank at C and let it fill up whenever there is pressure.

You need to know lengths and pressures though.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[mk3223]

If the water source from the point A is open to public without restriction, the better option, as a minimum, for the user C is to run a separate line from either the point A or B, if there is no issue for the money and the pipe material is available.

 

[Snickster]

I did a calculation to check differences in pressure drops in 1" Sch 40 PVC (ID 1.029") vs. 1/2" Sch 40 PVC (ID 0.602") at 10 GPM assumed possible total flow in the main header the pressure drops are:

In 1/2" pressure drop is 38 psi per 100 feet of length at 11.3 ft/sec velocity, 10 GPM

In 1" pressure drop is 3 psi per 100 foot of length at 3.8 ft/sec velocity, 10 GPM

So yes the 1/2" pipe header is way undersized and you will save a lot of pressure with the 1" pipe instead. However not knowing anything about the upstream system I cannot tell if there are any other issues in the system.