Can air move a water meter?

Looking for information or help in the field of DIY and home improvement. Post your questions, suggestions and comments here.
User avatar
Wicksey
Andalucia Guru
Posts: 3501
Joined: Mon Sep 20, 2004 1:21 pm
Location: Axarquia coast

Can air move a water meter?

Postby Wicksey » Sun Sep 11, 2016 12:21 pm

We are on the local agricultural supply for water which is always a bit hit and miss as to when the water is actually on. The meter (and therefore the on/off 'tap') is some distance from the house so it's not easy to regularly check when it may be on or not, particularly when it is up a very steep (and currently) hot hill from our house!

We turned it on yesterday and it just hissed a lot and although we couldn't hear water going through it the meter was spinning around and we wondered if it would move if just air went through the meter. Last year we ran out of water when, according to our calculations, we should have had 100m3 left in the tank. It is not our tank or 'action' of water, but we have control over turning it on and off and it serves just our house and a neighbouring little-used holiday home (where we have access to their water meter so know their usage). It is very difficult to see in it and huge (ie too big for a dip-stick to measure the height of water) so difficult to judge how much is in it

Although my OH thought he'd fully turned it off last night this morning the meter had moved another 15m3. The meter is relatively new so presumably not faulty. At the moment the water is not on although we thought it always was on a Sunday, so it's all a bit of pain trying to monitor what is happening. Having run out every year since we lived here and with possible water problems due to the drought (and extra usage on all the many 1000s of mangoes planted) we thought we should keep it topped up. I am not sure if there is a ballcock or not to turn it off, and we are limited to a monthly amount we can put in so can't just leave the tap on.

TorreDelAguila
Resident
Posts: 1356
Joined: Thu Jan 23, 2014 11:52 am
Location: Sayalonga

Re: Can air move a water meter?

Postby TorreDelAguila » Sun Sep 11, 2016 12:42 pm

Water meters are driven simply by a paddle (or worm) that spins round when water flows. Air flowing through will do this too.
If you want to stop it, there needs to be a tap in line with the meter, to prevent water or air flow along the pipe. The tap could be at your house end, for convenience, assuming nothing else is coming off the meter as well.

Air flow down periodically empty pipes is pretty common, when the water starts to flow again. The longer the dry incoming pipe, the more air will get pumped through!
Chris

User avatar
Wicksey
Andalucia Guru
Posts: 3501
Joined: Mon Sep 20, 2004 1:21 pm
Location: Axarquia coast

Re: Can air move a water meter?

Postby Wicksey » Sun Sep 11, 2016 1:16 pm

That's what I had wondered about. Our main tap is on a bank of about 7 water meters and the huge mains water pipe feeds it (which is off more than on). I don't think we can control the air that may be in the mains pipe. The other taps are usually off so maybe we are the first one to be turned on and get the air! Beyond the meter is a funny little valve thingy that hisses away sometimes, but I would have thought that this should have been before the meter if it is to bleed the system.

ebbnflow
Andalucia.com Amigo
Posts: 177
Joined: Mon Jun 10, 2013 8:36 pm

Re: Can air move a water meter?

Postby ebbnflow » Sun Oct 16, 2016 10:51 pm

The water company made us fit a valve immediately before the meter, while at it we also put in a plain "tap". We then have another valve and screw-spout proper tap on our side of the meter. The first one allows us to let the air out of the reconnected supply (very long supply pipe) and, more importantly, all the crud that comes first comes through. The water company have not complained/queried the installation.

TorreDelAguila
Resident
Posts: 1356
Joined: Thu Jan 23, 2014 11:52 am
Location: Sayalonga

Re: Can air move a water meter?

Postby TorreDelAguila » Mon Oct 17, 2016 7:44 am

The valve immediately before the water meter is probably a pressure regulator, and it is a good idea to fit one these to any property. Mains water pressure can be anything up to 25bar, and this is too high a pressure for a normal ball-valve (float valve) on a deposito or tank to cope with, and it would place considerable strain on your own domestic pipeline and its joints. Domestic properties need a pressure of 5bar maximimum, and this is what a correctly set pressure reducer can deliver. For routine deposito filling, pressure as low as 2bar is quite acceptable.

Pressure regulators should always be fitted with a pressure gauge and a shut-off tap on their output side. This latter tap needs to be closed in order to set the reducer to the required output pressure. Most pressure regulators already have a socket for fitting a setting gauge, which can be left in place. Pressure regulators rarely clog with silt, and can be expected to operate perfectly for years. They tend to flush themselves clean every time water flows through them.

Individual pressure regulators are also a good idea if you live in a hilly area. This gets over the problem of properties downhill getting excessively high pressures, or getting 'all the water' when it's scarce, and uphill properties being starved. Only works if most of the properties have one, but the downhill folk are the people to tackle first!
Chris

User avatar
Wicksey
Andalucia Guru
Posts: 3501
Joined: Mon Sep 20, 2004 1:21 pm
Location: Axarquia coast

Re: Can air move a water meter?

Postby Wicksey » Mon Oct 17, 2016 9:50 am

The main meters are the property of the water company and the contract isn't between us and the water company anyway, but it is doubtful that we could touch any of the installation even if it was.

They installed banks of meters, some are in special cabinets, but 'ours' is just open to the elements. Our personal water pipe comes down the hill from the neighbour's water deposito which fills from the mains water pipe, so our own pipework and meter is not a problem. It's just the question of whether we think we are filling the tank with water, when in fact some of the m3 is air! Being in the campo and on agricultural water, the whole system is different to those on town water

TorreDelAguila
Resident
Posts: 1356
Joined: Thu Jan 23, 2014 11:52 am
Location: Sayalonga

Re: Can air move a water meter?

Postby TorreDelAguila » Tue Oct 18, 2016 10:26 am

Yes, installations do vary, and it is not unknown for campo water companies to claim that a broken water meter is the responsibility of the house owner to replace! Even Endesa have tried this on, electricity-wise.

On the "air" issue, if you google "automatic air bleed valve" there are dozens of images/pages on these, how they work, and where to fit them. Essentially, when air is in the pipe, pressurised or not, they release it; when water is there, they close up. Good few fitted out this way, so obviously available.
Chris


Return to “DIY, Pools & Home Improvement”

Who is online

Users browsing this forum: No registered users and 23 guests