Mixing pipe sizes - total noob

[washedout]

Please help. Whilst I am a plumbing noob, I can turn my hand to most things - especially if I'm given a bit of advice along the way, and I'm hoping this is where you guys come in

We live on a really small, really remote little island. Our spring has dried up, so I am trying to cobble together a rain water system that is safe enough to shower in. Because of the weather this time of year, it's not really feasible to get a plumber over, although I can occasionally make sorties to the mainland to get supplies for an hour or two once every two or three or weeks when there is a break in the weather. And I like challenges like this, its fun. Anyway, onto the task at hand:

So far, I've got (or have on order)

* 1500 litre water tank filled with nice fresh rainwater, and a balloon float and filter which terminates in a G1 female fitting (brass, submerged).

* A 30 PSI, 12 litre/min pump with 1/2" male connections (plastic) - used these pumps before, they need flexi tails as they vibrate a bit

* A UV treatment lamp with 3/4" BSP female connections (stainless)

This needs to tee into an existing plastic feed from the spring, which is gravity fed from a holding tank up on the hill. (The spring fed supply will be turned off when this supply is in use; the spring is now dry anyway). By the time the spring supply enters the house its in a grey plastic pipe which I think is close (or actually is) 1" diameter. This pipe was fitted 14 months ago, so it's will be whatever is in vogue for internal fresh water use?

My very basic questions are: what is the best way to join this stuff together. Plastic pipe? Copper pipe? How do I best go about matching the differences in pipe sizes? What are the google-able names of the bits I need to buy?

The added slight complication is that I would like to fit stop valves on either side of the UV treatment lamp, with a T to a third drain valve, so that I can empty water out of the lamp in the case of power failure. This avoids the need to (technically) drain the whole system down as contamination can be contained in the event of power failure, and we know our power supply can be unreliable.

Thanks so much, all help is most appreciated!!

 

[vectra65]

the easy way to join plastic or copper is to use pushfit conectors ie speedfit or other makes you can get different sizes and also reducers for this

 

[washedout]

Thanks Vectra65. Perhaps I need to take this one step at a time. Working backwards from my main pipe - I would use speedfit to T into that? And then use 3/4" copper to the treatment lamp? Is that right? How would I mate with the treatment lamp - I need a 3/4" male BSP connector, is that a compression fitting or something different (the compression fittings I've seen before on the ends of pipes are usually female aren't they? So that can't be right? I'm not sure what a male one would look like - perhaps the documentation is wrong). Perhaps if we can solve this bit of the puzzle, I'll see the light and the rest will slot into place... Thanks again!

 

[vectra65]

the 3/4 bsp should be male thread at one end with a 3/4 compression to fit your pipe into you should screw the male thread part into your treatment lamp if its female connection then fit your copper pipe into compression end

 

[stevetheplumber]

assuming the uv light is in the supply line near the house you really only need an upstream valve to allow servicing, down stream wil run to house for drainage ? you realy only need two valves for an item in a circuit

 

[washedout]

assuming the uv light is in the supply line near the house you really only need an upstream valve to allow servicing, down stream wil run to house for drainage ? you realy only need two valves for an item in a circuit

Hi Steve, Thanks for helping out. This is what I had in mind:
[Rainwater tank ]-->[Pump]--->[X]--->[UV]--+---[X]---->[House]

|
[X]
Drain​

The [X] are stop cocks. I think you are saying I don't need the left hand cock? The pump is self-activating, so without it, I can't drain just the lamp - I suppose it doesn't waste much water, but then I also thought it would help if I needed to service the lamp for any reason, or if I anything sprang leak up stream of the pump... Or have I missed the point - wouldn't be surprised ;-)

 

[ecowarm]

The grey pipe you have coming from the spring, it could be solvent weld fittings in either metric or imerial.
Do the fitting look like this PVC-U Pressure Pipe Fittings Metric mm Solvent Weld ?

 

[washedout]

The grey pipe you have coming from the spring, it could be solvent weld fittings in either metric or imerial.
Do the fitting look like this PVC-U Pressure Pipe Fittings Metric mm Solvent Weld ?

Frustratingly the only visible fitting it has on it is the stopcock, the lever handle type. I am going to lift some boards and track back more of the run, hopefully I can find either a join after the stopcock so I can extract a fitting or something printed on the pipework somewhere.

I was talking to a mate earlier today about this project - he's done more plumbing than me - and his advice was to pick a pipe size and then standardise everything around that. His preference was for plastic over copper (cheaper, easier to work). On the face of it this seems to make a lot of sense - say I chose 15mm plastic (because that's the lowest common denominator in terms of connecting everything together) - then I'd be able to get some kind of inserts to go in the UV lamp to reduce from 3/4" BSP to 15mm? Only problem is so far I haven't been able to find them - probably because I haven't got the name quite right (3/4" x 15mm reducer? Or something else?)

Is there a flaw in this plan? Is restricting flow to 15mm going to cause me problems? If this will work, I think I can now see the wood for the trees, which is great...

 

[ecowarm]

Frustratingly the only visible fitting it has on it is the stopcock, the lever handle type. I am going to lift some boards and track back more of the run, hopefully I can find either a join after the stopcock so I can extract a fitting or something printed on the pipework somewhere.

I was talking to a mate earlier today about this project - he's done more plumbing than me - and his advice was to pick a pipe size and then standardise everything around that. His preference was for plastic over copper (cheaper, easier to work). On the face of it this seems to make a lot of sense - say I chose 15mm plastic (because that's the lowest common denominator in terms of connecting everything together) - then I'd be able to get some kind of inserts to go in the UV lamp to reduce from 3/4" BSP to 15mm? Only problem is so far I haven't been able to find them - probably because I haven't got the name quite right (3/4" x 15mm reducer? Or something else?)

.
Is there a flaw in this plan? Is restricting flow to 15mm going to cause me problems? If this will work, I think I can now see the wood for the trees, which is great...

Its best not to reduce from what you have coming in, it is that size for a reason. Try to find out what pipe you have. You can't speculate until you know. If its somthing like solvent weld Wras APROVED fittings and pipework then speedfit and the like will not fit. See what you have first before diving in head first. post some pics. If you cut the pipe and you have the wrong fittings you are in the POO, being in such a remote place it could take days or weeks before you have water restored

 

[justlead1]

Hi. Whilst redesigning and fitting this system, i would consider having the water qualities examined. On a couple of occasions over the years i have come across cupro solvent water via a spring, which corroded copper pipe within the properties it feed. A print out of water characteristics may also give comfort if you and yours intend to drink it.

 

[washedout]

Hi. Whilst redesigning and fitting this system, i would consider having the water qualities examined. On a couple of occasions over the years i have come across cupro solvent water via a spring, which corroded copper pipe within the properties it feed. A print out of water characteristics may also give comfort if you and yours intend to drink it.

Yes, good point. We do have the spring water tested annually - we have a wacky long standing arrangement with the council whereby we drop a bottle off by boat with the council chappy once a year, meeting him on the quay. It usually comes back as slightly marginal for general bacteria, but otherwise ok - we filter it for drinking, but none of the four us living here have ever suffered any ill effects health wise, I expect we have built up a resistance. Pipe work corrosion is more difficult to assess - given that everything rusts instantly in the sea air ;-)

I guess we'll do the same testing-wise once we're treating rainwater. If the spring comes back, we'll probably drink filtered spring water and use treated rainwater for everything else (washing bodies, crockery).

 

[washedout]

Its best not to reduce from what you have coming in, it is that size for a reason. Try to find out what pipe you have. You can't speculate until you know. If its somthing like solvent weld Wras APROVED fittings and pipework then speedfit and the like will not fit. See what you have first before diving in head first. post some pics. If you cut the pipe and you have the wrong fittings you are in the POO, being in such a remote place it could take days or weeks before you have water restored

Some interesting progress this afternoon, after a bit of intrepid investigation...
Lifting some boards got me some pipe markings on my existing incoming feed - shows how rubbish my measuring probably is - "22 x 2.0mm PB H&C". Also, the stopcock has the following markings on it: "CG MGP5 CE". Digging around in the undergrowth outside, I found where it joins up with the distribution from the main holding tank - there's an adapter from 25mm MDPE, so the incoming spring water pipe I want to tee into must 22mm (with a 2mm wall?) mustn't it?

So what is the best plan now then - do all my new plumbing in 22mm and get adapters from 22mm to 3/4" (do they exist?) What about my pump - which is 1/2"?

 

[johnnyplumb]

I can help you on this one, i'm a real expert in this field. what you need to do is press the big red button on the bottom right hand side once only, I cant stress enough to press it only once. if you press it more than once you'll live to tell the tale.

 

[washedout]

Finally took the bull by the horns and tackled the project head on. It turned out it wasn't so hard once I got started - it took most of the weekend, but then it was my first ever plumbing project beyond changing a washer.



Thanks to all the guys on here for your help, couldn't have done it without you. The bloke in the local plumber's merchants was really patient and gave me some great tips as well. Any constructive criticism gratefully received! (PS Don't worry about the pump electrics - they are low voltage).

Cheers
Washedout