Water Pipe Repairs

[Pattaya Spotter]

The shut-off valve from my water tank to the house pump has sprung a leak and needs replacement. The pipes and valve are all made of the blue PVC water pipe material. Can the plastic cement that is used to join the pipes also be used at the joints to unjoin them...or is it better to cut out the section of pipe with the valve and replace it?

[Crossy]

You have to cut out the damaged valve and replace it along with some pipe.

 

Exactly how you do it depends upon the actual arrangement of the pipes.

 

Drop some photos of what you have for directed comments.

[Pattaya Spotter]

13 minutes ago, Crossy said:

You have to cut out the damaged valve and replace it along with some pipe.

 

Exactly how you do it depends upon the actual arrangement of the pipes.

 

Drop some photos of what you have for directed comments.

As near I can tell, the leak is from the red valve spigot and not the pipe joints. The work space is a bit tight (about half a meter) and there isn't much leed pipe to work with at the top to splice in a new valve.

[johng]

Its supposedly possible to heat the joints and "unglue" them  but I had no success with that method  using a LPG blow torch   a hot air paint stripper or  soldering station with variable temperature might do better ?

The heat also damaged another part stuck in the wall so I couldn't actually glue the new bit in without leaks

however the every usefull 2 part epoxy resin soon did the trick  it even sets  with water in the pipes...not under pressure just  no need to totally dry the joints like you do with PVC glue.

[johng]

I just saw the photos,put a bucket underneath and hire a maid to come empty it  twice per day ????

[Pattaya Spotter]

1 minute ago, johng said:

I just saw the photos,put a bucket underneath and hire a maid to come empty it  twice per day ????

Cheaper to just pay for the lost water...it's a slow leak ????

[Crossy]

I would cut the pipe next to the valve on the long side and replace everything to the screw fitting on the tank the other side.

 

OR

 

Get a decent metal valve and fittings and thread the valve into the tank. Then you can use PVC to link to the existing pipe.

 

[Pattaya Spotter]

7 minutes ago, Crossy said:

I would cut the pipe next to the valve on the long side and replace everything to the screw fitting on the tank the other side.

 

OR

 

Get a decent metal valve and fittings and thread the valve into the tank. Then you can use PVC to link to the existing pipe.

 

Thanks. The pipe piece attached to the tank is a screw fitting and not pipe cemented on? So just cut maybe an inch below the valve and assemble a new elbow joint, replace the screw-on tank outlet, and then cement the new elbow joint/valve piece in place?

[Crossy]

10 minutes ago, Pattaya Spotter said:

Thanks. The pipe piece attached to the tank is a screw fitting and not pipe cemented on? So just cut maybe an inch below the valve and assemble a new elbow joint, replace the screw-on tank outlet, and then cement in the new elbow joint/valve piece in place?

 

Yup, that would do the trick. You'll need to plan and empty your tank so you don't waste the contents of course.

 

[Pattaya Spotter]

5 minutes ago, Crossy said:

 

Yup, that would do the trick. You'll need to plan and empty your tank so you don't waste the contents of course.

 

Not sure about the last part...I guess I'll have to snut-off the pump and drain the tank (bottom spout) in order to do this. There is no place to store the water so it will go to waste. Good opportunity to clean out the tank, though, as there is quite a bit of sediment at the bottom.

[Crossy]

Just now, Pattaya Spotter said:

Not sure about the last part...I guess I'll have to snut-off the pump and drain the tank (bottom spout) in order to do this. There is no place to store the water so it will go to waste. Good opportunity to clean out the tank, though, as there is quite a bit of sediment at the bottom.

 

Get the parts.

 

Turn off the inlet to the tank.

 

Use water until the tank is empty. Store water by the loo and kitchen so you can flush cook.

 

Do the job.

[Pattaya Spotter]

43 minutes ago, Crossy said:

 

Get the parts.

 

Turn off the inlet to the tank.

 

Use water until the tank is empty. Store water by the loo and kitchen so you can flush cook.

 

Do the job.

Of course...silly me ???? While I'm at it, I should probably change the smaller inlet valve too as it gets sun too and may be getting brittle.

 

As I'm in Pattaya, I have plenty of water in storage in barrels and bottles around the house due to the draught and intermittent water shut-offs.

[DrTuner]

The way I usually do these is to get 4 90 degree pieces. Cut the pipe and put 2 in the old pipe so they point out. Put whatever piece you need (a valve in your case I think) together with the other 90 degree pieces. Push together. Done. Sometimes when I feel fancy I use the joints that have flat flanges that screw together. It's an art form.

 

Pro tip: use a cheap toothbrush to spread the PVC glue and lightly sandpaper the connecting surfaces.

[DrTuner]

1 hour ago, johng said:

I just saw the photos,put a bucket underneath and hire a maid to come empty it  twice per day ????

That's the Thai solution to it. Works too.

[carlyai]

You could try the 3M electrical tape that stretches and wrappes around and sets like a blob. I've had success with that method a few times.

I'll hobble out and take some pics if you are interested.

[johng]

38 minutes ago, Pattaya Spotter said:

I should probably change the smaller inlet valve too as it gets sun too and may be getting brittle.

Be very careful  while trying to get everything apart and then back together the PVC could easily shatter from too much bending..if not too late already its a good idea to protect the PVC from the intense UV with a coat of  glossy paint  and maybe use metal valves.

[DrTuner]

3 minutes ago, johng said:

Be very careful  while trying to get everything apart and then back together the PVC could easily shatter from too much bending..if not too late already its a good idea to protect the PVC from the intense UV with a coat of  glossy paint  and maybe use metal valves.

Yeah old PVC pipe can be brittle, especially if exposed to sun. Applying a hot air gun carefully at about 120degC until you see slight change in surface texture makes it a little less likely to crack into pieces. It's a PITA especially if you have very little to work with in case it goes inside a wall, f.ex.

[Pattaya Spotter]

35 minutes ago, carlyai said:

You could try the 3M electrical tape that stretches and wrappes around and sets like a blob. I've had success with that method a few times.

I'll hobble out and take some pics if you are interested.

Thanks but I imagine any temporary fix will eventually leak as well so might as well go for a permanent fix. This is a small job so I should be able to DIY it myself.

[Pattaya Spotter]

34 minutes ago, johng said:

Be very careful  while trying to get everything apart and then back together the PVC could easily shatter from too much bending..if not too late already its a good idea to protect the PVC from the intense UV with a coat of  glossy paint  and maybe use metal valves.

Good suggestion about the paint...I'll go ahead and add a coat to the exposed pipes when I've done the repairs. If using metal valves, how do you fit them to the plastic PVC pipes?

[johng]

3 minutes ago, Pattaya Spotter said:

If using metal valves, how do you fit them to the plastic PVC pipes?

They are threaded  either male or female   so you would have to get the corresponding threaded bit of PVC

and use some Teflon plumping tape wrapped around the treads to seal them..test fit  the treads before glueing everything else as sometimes they are a good fit and need  not so much tape  but more often are very sloppy fit so need lots of tape to seal.

[Pattaya Spotter]

2 minutes ago, johng said:

They are threaded  either male or female   so you would have to get the corresponding threaded bit of PVC

and use some Teflon plumping tape wrapped around the treads to seal them..test fit  the treads before glueing everything else as sometimes they are a good fit and need  not so much tape  but more often are very sloppy fit so need lots of tape to seal.

Maybe I'm missing something...I understand the metal valves are threaded but I've never seen threaded PVC pipes...only smooth ends.

[Cake Monster]

2 hours ago, johng said:

Its supposedly possible to heat the joints and "unglue" them  but I had no success with that method  using a LPG blow torch   a hot air paint stripper or  soldering station with variable temperature might do better ?

The heat also damaged another part stuck in the wall so I couldn't actually glue the new bit in without leaks

however the every usefull 2 part epoxy resin soon did the trick  it even sets  with water in the pipes...not under pressure just  no need to totally dry the joints like you do with PVC glue.

There is an Epoxy Resin Glue available from most Hardware Stores that is specific to Water Leaks

Just go in and ask - not expensive and can be used if the leak is a little wet.

[bankruatsteve]

5 minutes ago, Pattaya Spotter said:

Maybe I'm missing something...I understand the metal valves are threaded but I've never seen threaded PVC pipes...only smooth ends.

Yup, you're missing something.  ????  

You need the couplers for that though.

[Pattaya Spotter]

10 minutes ago, Cake Monster said:

There is an Epoxy Resin Glue available from most Hardware Stores that is specific to Water Leaks

Just go in and ask - not expensive and can be used if the leak is a little wet.

I believe the leak is coming from the red valve on/off switch (not the pipe joints)...using a glue to seal it would prevent using the valve. Lots of good suggestions here...should be able to get this sorted now with a trip to Home Pro.

[Moonlover]

2 hours ago, johng said:

Its supposedly possible to heat the joints and "unglue" them  but I had no success with that method  using a LPG blow torch   a hot air paint stripper or  soldering station with variable temperature might do better ?

The heat also damaged another part stuck in the wall so I couldn't actually glue the new bit in without leaks

however the every usefull 2 part epoxy resin soon did the trick  it even sets  with water in the pipes...not under pressure just  no need to totally dry the joints like you do with PVC glue.

You cannot 'melt the glue' because it isn't glue at all. It's a solvent that softens the the surface. When you make the joint the two parts blend together and harden again. It essentially becomes one piece of pipe.

[johng]

14 minutes ago, Cake Monster said:

There is an Epoxy Resin Glue available from most Hardware Stores that is specific to Water Leaks

Just go in and ask - not expensive and can be used if the leak is a little wet.

I just used the "all purpose" stuff I had already..  it's  labeled for fixing rebar to concrete but works for most everything.  well didn't last too long on a motorcycle  exhaust pipe ???? 

[johng]

21 minutes ago, Moonlover said:

You cannot 'melt the glue' because it isn't glue at all.

Maybe that explains why it didn't work for me ????

[johng]

1 hour ago, Pattaya Spotter said:

Maybe I'm missing something...I understand the metal valves are threaded but I've never seen threaded PVC pipes...only smooth ends.

[Pattaya Spotter]

2 minutes ago, johng said:

Guess I didn't look close enough ???????????? I was only thinking of the long straight pipe lengths and not that I can make custom threaded ends by cementing appropriate fittings to the ends of them.

[teacherclaire]

3 hours ago, Crossy said:

I would cut the pipe next to the valve on the long side and replace everything to the screw fitting on the tank the other side.

 

OR

 

Get a decent metal valve and fittings and thread the valve into the tank. Then you can use PVC to link to the existing pipe.

 

It's pretty easy to work with these PVC pipes.

 

Give it a try and use some better valves that do not fall apart after one month.