nabbers Posted September 14, 2017 Author Report Share Posted September 14, 2017 Just to add, do u own the ground where the tank/pipes are?? By rights it should be in ur title deeds but if its an old system it should be all ok. If the pipes are alkyethene any leaks are more likely to be at joints being forced apart rather. than holes in the pipe. usually the filters/UV light is inside the house just after ur stop cock The 1 problem u might have with putting a new tank inside the old 1 is connecting the outflow pipes. I might be tempted to dig the front face away so u have good access to connect everything up, but there may be other ways to plumb it soit may not be a problem, but nit a big jo for mini digger and realy not a massive job to hand ball either The Ownership of the ground is not us, but we have rights in place. I think a new section of out flow pipe is in order, replacing the faulty stop cock as we go, so fitting a new plastic tank might be straightforward, Just wish I hadn't sold my quad bike... My next problem will be identifying the various pipe sizes... Quote Link to comment Share on other sites More sharing options...
scotslad Posted September 14, 2017 Report Share Posted September 14, 2017 Aye that can be a problem, u'll need to find ur self a decent plumbers merchant. The 1 I use when I 1st went in trying to find old pipe fittings came out with a poly bag full of different old pipe sizes all slightly different sizes or materials Quote Link to comment Share on other sites More sharing options...
figgy Posted September 14, 2017 Report Share Posted September 14, 2017 Over a run of 800 meters or so as you say half a mile, go larger rather than smaller due to frictional loss in flow. The size you choose wants to be commonly available for future repairs, valve replacement etc. be worth finding out the pressure you have where it enters your tank so you know the spec you need. Can be a lot of pressure from top of a hill to the bottom of it. Every 100 foot of height is 43.3 psi of static head pressure. The sizes of alkathene pipe are outside diameter. Checking the flow rate of your current pipe will tell you if you need to increase or can decrease the size. Ideally for water supply you want 7 liters a minute. Do you have branches off for hose pipes before going into tanks or is it all fed from your holding tanks ? Quote Link to comment Share on other sites More sharing options...
ditchman Posted September 14, 2017 Report Share Posted September 14, 2017 Over a run of 800 meters or so as you say half a mile, go larger rather than smaller due to frictional loss in flow. The size you choose wants to be commonly available for future repairs, valve replacement etc. be worth finding out the pressure you have where it enters your tank so you know the spec you need. Can be a lot of pressure from top of a hill to the bottom of it. Every 100 foot of height is 43.3 psi of static head pressure. The sizes of alkathene pipe are outside diameter. Checking the flow rate of your current pipe will tell you if you need to increase or can decrease the size. Ideally for water supply you want 7 liters a minute. Do you have branches off for hose pipes before going into tanks or is it all fed from your holding tanks ? well done ..........thats what a lot of people tend to forget.............."what loss of flow due to friction of the water in the pipe ....nnaaaaa"................i fell foul of this a long while ago...and i still dont know what im doing....hydraulics is a minor science Quote Link to comment Share on other sites More sharing options...
iano Posted September 14, 2017 Report Share Posted September 14, 2017 hydraulics is a minor science major science. I remember dynamic manifold equations back in college. Couldn't figure them out then, still haven't the foggiest. Back on topic - just reiterating the advice of having a couple of shut off valves on the way of the pipe. We have this and it made fixing a leak a lot easier then trying to figure out where the issue was (however, given the issue was one of the valves themselves, I'm not sure if this counts...) Quote Link to comment Share on other sites More sharing options...
ditchman Posted September 14, 2017 Report Share Posted September 14, 2017 major science. I remember dynamic manifold equations back in college. Couldn't figure them out then, still haven't the foggiest. Back on topic - just reiterating the advice of having a couple of shut off valves on the way of the pipe. We have this and it made fixing a leak a lot easier then trying to figure out where the issue was (however, given the issue was one of the valves themselves, I'm not sure if this counts...) remember way back abroad i laid 200m of plastic 3/4" pipe from a small damn down to one of my crushers.........i tell you boy i could urinate faster that how it came out...ended up laying a 4" pipe 150m then down to a 3" pipe to the crusher then took off 3/4" spurs......... Quote Link to comment Share on other sites More sharing options...
McSpredder Posted September 14, 2017 Report Share Posted September 14, 2017 As others have said, don’t stint on pipe size -- a small increase in diameter always brings a major reduction in head requirement. Simple formula for pipe flow, easy to use in any spreadsheet: Head = k * (flow rate)^2 / (internal diam)^5 * (pipe length) For normal water flow, I use these units: Flow rate (m3/s) Pipe internal diameter (m) Pipe length (m) Head (m) k = 0.0022 Referring back to figgy’s post (#28), if you needed a flow of 7 litre/minute (=0.00012 m3/s) down an 800m length of pipe with internal diameter 15.4mm (20mm OD alkathene), the calculation would be: Head required = 0.0022 * (0.00012)^2 / (0.0154)^5 * 800 = 29m … but if you increase the pipe size to 25mm OD (internal diam 20mm), the head required is only 8m. There are loads of other formulae, some of them quite complex (best avoid the Hazen-Wiliams or Colebrook-White calculations unless you are either a mathematician or a masochist), and I found they all produced fairly similar answers, for anything from little cattle troughs supplies up to large irrigation schemes. Methods are available for calculating pressure drop at every pipe bend, junction, valve, etc, but the value for “k” in the formula above includes a simple extra 10% head loss allowance for all these. Quote Link to comment Share on other sites More sharing options...
Bazooka Joe Posted September 14, 2017 Report Share Posted September 14, 2017 If its the supply pipe which is half a mile long then how do I find the leak? Could you not use what's in the link below to find the leak.? https://www.brightdyes.com/dye-color/green/ Quote Link to comment Share on other sites More sharing options...
nabbers Posted September 14, 2017 Author Report Share Posted September 14, 2017 Hmm this thread got very technical! I isolated the outflow and the tank level didn't rise, meaning the pipe might still be OK. Don't think any science was applied when it was put in, but if it aint broke yet, not fixing it! Then found a hole in the tank and stopped that up, level went up 6" then found more holes at the new water line. https://static.kingfisheruk.com/specs/data/aquatechpds46iss7.pdf Could tank it out using this stuff, source a better lid and then job on the hill is done for another 40years, or until the pipe does leak! Or may fit plastic or GRP tank. There are no holding tanks at the house, just a hotter tank and a toilet cistern, don't use much water here to be honest! Filter sounds essential, currently there are none. Quote Link to comment Share on other sites More sharing options...
pycoed Posted September 18, 2017 Report Share Posted September 18, 2017 (edited) I went through exactly this process about 20 years ago. I'd replace the tank with a proper potable water tank which will have a screw lid & be black plastic. Try to get plenty of cover for it so as to keep it cool in summer. Fit at least a 40mm wastepipe as the outlet from the tank if your inlet is 25mm to ensure a constant flow through the tank, but no chance of pressurising in times of large spring flow. Don't use a filter if you are happy without one - it'll clog at the most inopportune moment. Don;t let on to the council if you share the water or they'll be around poking their nose in & requiring annual testing & they will charge top whack for it (typically 3 times the charge you can get it done yourself via a hospital path lab!) UV kits can be fitted for a normal house for under £200 if you fit it yourself - personally I wouldn't have bothered except the council Gestapo got involved since our spring is shared. Even if you are happy with the potability of your supply, do get your water checked for ph because if it's low, it'll eat copper so if you get pinholes in the house pipes you may have to replumb in plastic (don't ask how I know!) PS DO fence the spring & holding tank to keep stock out! Edited September 18, 2017 by pycoed Quote Link to comment Share on other sites More sharing options...
figgy Posted September 18, 2017 Report Share Posted September 18, 2017 If you been using it for forty years the chance of anything nasty in the water will be low. Your still here and not complaining of bad guts. Now your main tank is knackered fir a plastic one inside it, it should keep it cool and protect it a bit from the weather. Put a hole on bottom of outer tank to act as a drain if you retro fit one inside, you don't want standing water getting stagnant near your potable water. Quote Link to comment Share on other sites More sharing options...
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