Pressure drops when 650 litre buffer tank is filled with water but no drop with air

[Trevor Rix]

Re: Pressure drops when 650 litre buffer tank is filled with water but no drop with a

have you pressure tested the system yet?

Please read the whole thread.

 

[Trevor Rix]

Re: Pressure drops when 650 litre buffer tank is filled with water but no drop with a

Wierd !

Air will obviously contract a lot. So the temperature of air put in, once stabilised will drastically change pressure just like testing a large gas installation but you've thought of that ?

I am not sure I follow what you are saying. How is that relevant?

 

[ShaunCorbs]

Re: Pressure drops when 650 litre buffer tank is filled with water but no drop with a

Please read the whole thread.

I have also you haven't tested the whole install only sections which is not good enough

 

[Trevor Rix]

Re: Pressure drops when 650 litre buffer tank is filled with water but no drop with a

I have also you haven't tested the whole install only sections which is not good enough

Only two sections dropped pressure so it was those two sections that were most intensively tested.

To be clear, the pressure drops occured when the system was filled with water. The sections that were losing pressure stopped losing pressure when that water was replaced with pressurised air. When that pressurised air was replaced with water there continued to be no pressure drops.

 

[ShaunCorbs]

Re: Pressure drops when 650 litre buffer tank is filled with water but no drop with a

Only two sections dropped pressure so it was those two sections that were most intensively tested.

To be clear, the pressure drops occured when the system was filled with water. The sections that were losing pressure stopped losing pressure when that water was replaced with pressurised air. When that pressurised air was replaced with water there continued to be no pressure drops.

For a start you can't pressure test with air anything over 0.5 bar needs to be water

 

[Trevor Rix]

Re: Pressure drops when 650 litre buffer tank is filled with water but no drop with a

For a start you can't pressure test with air anything over 0.5 bar needs to be water

Well, the reason for testing with air was that there were no visible water leaks. So air was tried to see if bubbles appeared in the exposed underground pipework that was covered with water.

The result was unexpected. No more pressure drops!

 

[ShaunCorbs]

Re: Pressure drops when 650 litre buffer tank is filled with water but no drop with a

Well, the reason for testing with air was that there were no visible water leaks. So air was tried to see if bubbles appeared in the exposed underground pipework that was covered with water.

The result was unexpected. No more pressure drops!

I've had fittings tested on air and no leaks come to water test leak so get your plumber to test the whole system to 10 bar water and leave it for half a day (if you can't 2-3 hours will do)

soon see what's at fault

 

[Last Plumber]

Re: Pressure drops when 650 litre buffer tank is filled with water but no drop with a

I am not sure I follow what you are saying. How is that relevant?

If the air you pump into the system is, for example at 21 deg or room temp and you push it into buried pipes, that are say 12deg ( in the ground), the air will contract a lot as the temperature stabilises.

This will give the impression that you're loosing pressure when you're not.

i don't know if they waited when testing with air or give it up straight away.

To me it sounds like that's what happened. You said you had no leak when filled with water !

 

[Trevor Rix]

Re: Pressure drops when 650 litre buffer tank is filled with water but no drop with a

If the air you pump into the system is, for example at 21 deg or room temp and you push it into buried pipes, that are say 12deg ( in the ground), the air will contract a lot as the temperature stabilises.

This will give the impression that you're loosing pressure when you're not.

i don't know if they waited when testing with air or give it up straight away.

To me it sounds like that's what happened. You said you had no leak when filled with water !

Unfortunalely you have not understood what I have written in this thread. Your comments are therefore irrelevant.

There was no pressure drop when air was in the system, nor when the air was replaced with water.

The testing with air took place over several days.

 

[Last Plumber]

Re: Pressure drops when 650 litre buffer tank is filled with water but no drop with a

Well Trevor,
I have read the thread and commented throughout.
I am only trying to offer suggestions to the ridiculous sounding situation you're in.

It has gone on a while now and I admit I've kind of lost where we're up to.

For the life in me, I don't understand why your installer hasn't solved this by now. It is extremely difficult reading threads and other people's posts, in trying to solve a problem like this
I.e. Not physically dealing with it.

All that said, I understand that you think my comments are 'irrelevant '.

I wish you luck with this. I hope you get to the bottom of it soon.