Greetings! This is my first time on the forum. I'm in the Dominican Republic serving as a missionary with my family currently. Water supply to indoor plumbing here (as in most third-world countries) is a little different than the US. Water is delivered to the building (either at certain times throughout the day/week) via municipal water lines or via a tanker delivery. The water is stored in a large tank that is typically stored on a roof, and gravity feeds the indoor plumbing.

Our ministry has a warehouse with one of these large tanks that is fed through a municipal water line. Recently, a leak developed at the point where the tank connects to the building's plumbing (an outlet near the bottom of the tank). We had a local plumber (and the term is used very loosely here) 'fix' it. Now there is a leak at the connection to the standpipe (about a foot or so from the tank connection) and one at a connector he removed to drain the tank, and the connection point is still leaking!

I've gotten a lot of practice working with PVC since moving here in April, so I'm going to attempt to fix the initial problem and his leaks. I'd like to just cut off the pipe before the standpipe and replace everything from the standpipe to the tank connection (includes the standpipe, a ball valve, and a check valve; about two feet total).

My problem/question is this: This short length consists of nothing but the valves and connectors (both straight and elbows). There's no length of plain pipe to cut and cement new connector/pipe to. In fact the 8 - 10" before the standpipe is several elbows, making sort of a square, which is connected by an elbow to the pipe coming up from the cement block. The last elbow literally is flush with the top of the cement poured into the block.

If I were to cut into one of these connectors, how could I connect new pipe/connectors to them? If it will help to answer my question, I can post a photo later. I didn't think to take one today.

Thanks in advance for any advice!

Marty

A picture would help, as would the size of pipe you are dealing with. Just from your initial description, about the only item that would save you a major headache is a RamBit to drill out a couple of the old fittings, particularly where it enters the concrete. If not, you may have to carefully drill the concrete to a swiss cheese like texture and carefully break it away to get to some intact pipe. People here are pretty resourceful, so I have a feeling that more options are forthcoming.

Plan for the worst. So have a way to get at more pipe in the concrete first. You could cut the first elbow above the block off at the bend and above where the pipe is you want to get too. Then take a hack saw blade and cut slits vertically in the whats left of the fitting. make sure not to cut the pipe inside and go all the way from top to bottom of the fitting. Make a couple about 1/8 to 1/4 inch apart. Then take a chisel or a flat screw driver and hammer and be very patient and chip the notch out of the fitting. Then usually you can work from that notch around the pipe to get the rest of the hub off the fitting. You can do it in reverse and get the pipe out of the hub of the fitting the same way. But in my minds eye I think it would be easiest on that scure stand pipe. Problem being if you crack the pipe....then you get to chip some concrete. Then putting it back unions are your friend. Or you could get a food safe rubber coupling of the appropriate size that will seal perfectly around the hub of two fittings. Since its gravity and your toward the top of the system you arent facing much pressure. The square sounds like previous repairs. If you have two fixed pipes on each side of a leak you can make a offset to allow you to get it together. This is if you have not discovered unions yet.

I suspect that a flexible connector might be better on this installation, like a water heater supply line once the pipes are exposed. It is possible that the past repairs have been due to movement of the lines, and they broke due to being rigid. Allowing something which has the ability to flex between the building and the tank might be the key in longevity in this situation.

Thanks, KC & Hawaii for your quick replies. I'm going to try to get there today to take a couple of photos to post before I start something I won't be able to finish! I think KC mentioned "longevity" in his latest post, and that hits the nail on the head with how any repairs are made here. They are interested in solving the immediate problem, without consideration for future consequences. And, that's probably how I've wound up in this situation.

Stay tuned for some photos!

Marty

Okay... Had a photo shoot at the warehouse today. So, for more detail of what I'm dealing with, you can access four photos here:

[1drv.ms]

Looks like this is 3/4" pipe.

On one of the pics, I've pointed out a small - maybe 1/2" - section of pipe that is 'available.' Is it possible (or advisable) that if I can make a clean cut as close to the fitting on the left, that there will be enough pipe to attach a connector? If so, the rest will be easy.

Also, I liked the suggestion of a flexible pipe coming off the tank. It's not critical as the tank would rarely, if ever, have to be moved. But, it would seem to make future maintenance easier. Not sure if it's even available here. What type of connectors are used to connect with the pipe?

Thanks again for your help and suggestions!

Marty

Besides the use of pvc instead of cpvc for potable water, and what appears to be a ball valve for gas, there are a couple of problems that I think need addressed as well. The standpipe is open for anything to fall or crawl into it at any time. Also, it looks like a lot of the fittings were forced into place and torqued around. It isn't surprising that it leaked, as the whole contraption is unsupported and unsecured. Before I ask anything else, does the tank get emptied or would it pose a problem if it was emptied while you completed repairs? Is it filled on a schedule?

Why does the tank have to be filled from the top? If the fill riser and check valve were omitted, the incoming pumped water would still fill the tank(from the bottom up) and you would have a lot less fittings/leak potentials. I could see the top fill, if the pipe that supplies the building from the tank was separate from the pumped fill pipe, but since it's the same pipe, I would eliminate the excess.

I'd cut the pipe to the left of the valve, unscrew the PVC male adapter out of the valve and take off with new piping from there.

Greetings, again! First, thank you for all your input and questions so far. I am hugely grateful for the help!

KCRoto - I failed to mention the water in these tanks is not used for drinking or cooking, only for washing and waste. (I have no doubt that some local folks consume water from these systems, however). So that explains the PVC vs CPVC, as well as the open standpipe. And yes, I agree with your assessment of how it was put together (which again, is rather typical here). In fact, when he put the pipe into the connector at the bottom of the tank, he jammed the tank from behind to push it onto the pipe. I suspect that's what caused the second leak. The tank is currently empty, and does occasionally become empty. It is not filled automatically, as the municipal supply is delivered somewhat erratically. The 'street' water flows generally every morning for several hours. We have to manually start a pump to force water up to the tank from the street supply.

Steve - I also did not mention that the top pipe has a float valve attached to it to prevent over-filling the tank. I assume that's the reason for the top inlet.

North Carolina - I had not thought about that option, but it makes perfect sense to me!

Thanks again for the input and questions. I truly appreciate the help. If you're ever in the southwest part of the Dominican Republic, look me up!

Marty



Edited 1 times.

I think North Carolina Plumber has the most effective route, but I would add in a 3/4" flexible supply line between the ball valve and the T for the water inlet (as marked in the picture). Also, the pvc lines need to be braced against movement so you don't have something break due to gravity. It doesn't have to be fancy- a block of wood or stone would help. A flexible water heater connector and a brass or galvanized nipple to connect back to the ball valve, and a male adapter on the tank side will have you operational in no time. Adding in a few inches of pvc in there to allow for any future work would be beneficial as well, space permitting.

The entire assembly could use a few unions, which would greatly help with assembly and any needed future repair work. IMO, Installing the many threaded connections without even one union is what has caused problems.

Not a plumber

Thanks, everyone, for your helpful suggestions. This mess really had me baffled and I thought would be a major effort (busting up concrete block to get to some pipe) to fix. I now have the info I need to fix it and leave it better than the original installation (it's only about two years old). I'm very grateful for your sharing your time and knowledge!

Marty



Edited 1 times.

Marty, what's the purpose of the standpipe?

air relief on a gravity flow. It would be just as simple to have a 3/8" hole in the tank I would think, but whatever.

Haha, I asked the same question, Steve. Thanks for answering it, KC!

Funny thing is, many people don't even close the top of their tank. I keep ours closed to minimize the possibility of mosquito breeding (plus adding bleach occasionally). But, the hole where the inlet pipe comes in near the top is not sealed, either. The pipe kind of just goes through the hole, with the float valve at the end. The pipe itself can freely move in or out. So, my guess is the standpipe doesn't do much. On the other hand, I know someone else who did not install a standpipe. There tank is on the roof of the third story. They had an issue that when the tank was about half full, water pressure almost didn't exist. They ended up installing a pump.

Things here are quite intriguing!

Marty

Marty, if the tank is "vented" at the fill pipe (and the tank needs to be vented) there no need for the standpipe. If the tank wasn't vented, I don't see the standpipe doing anything regarding the gravity flow. Air needs to enter the tank, to make up for the exiting water. The open standpipe will fill with water, to the same level as inside the tank and I don't see air being sucked down the standpipe and entering the tank as the water level in the tank drops.

If the tank was airtight, the water in the standpipe would drain down till it 'burped' air back into the tank to relieve pressure but I agree it isn't necessary, and if it were me, I would have a vented tank lid. I assume that someone sells it because it looks like just an agricultural water tank to me. It would allow airflow, prevent mosquito larvae (as op mentioned), and allow access for chemical treatment as necessary.