Plumbing connection question

[julianthegypsy]

I'm hoping someone can help. I'm making a block from aluminium which will have hot water running through it. What I want is to be able to connect a 15mm pipe on one end and the same on the other. What size do I need to bore the hole for the pipe, what thread and what angles etc. I hope someone understands this as I don't think I'm being very clear, I just want to push a pipe in and tighten a connector of some sort but I'm b******* if I know where to begin to get instructions on how to do it, google just throws up screwfix et al selling connectors! Many thanks.

 

[S-Rail]

15mm pipe fittigs , compressions are 1/2 inch , you could tap your block 1/2 BSP and use two 15mm compression to 1/2 male thread , commonly available is chrome or Brass , get decet ones from a supplier , not wickes / toolstation etc .....

 

[Maker]

Can't you just drill 15mm and solder the pipes in?

 

[Wendelspanswick]

Do you mean a 15mm copper pipe and you want to bore and tap the block of aluminium so that you can use a compression fitting ring and internal boss?

 

[Tigman]

Sam is spot on with that one !

 

[gaz1]

heres another type a tank connector

http://www.screwfix.com/p/pegler-prestex-px35-flanged-compression-tank-connector-15mm/6146g

the only thing you need to do is seal it up so use a gasket sealer

 

[julianthegypsy]

Do you mean a 15mm copper pipe and you want to bore and tap the block of aluminium so that you can use a compression fitting ring and internal boss?

That's exactly what I was thinking! Soldering a pipe in might also work, I hadn't considered that. Good idea or not? Thanks for the brilliant advice everybody, as always on here the cavalry can be relied upon!

 

[zx9]

That's exactly what I was thinking! Soldering a pipe in might also work, I hadn't considered that. Good idea or not? Thanks for the brilliant advice everybody, as always on here the cavalry can be relied upon!

I don't see how you are going to solder a copper pipe to an aluminium block, Sam's compression fitting is the obvious way to go.


Edit : SP

 

[normspanners]

 

[Kent]

Don't know exactly what you're doing but dealing with compression fittings in three different materials and thicknesses is best avoided if you can.
Reason being they will tend to leak due to different rates of expansion and contraction
This might be critical or a no matter depending on application
Cheaper combination boilers are a swine for this on the hot water heat exchanger units

 

[julianthegypsy]

So what size hole do I have to drill for a 1/2" bsp thread? Quite a big one obviously!

 

[eSCHEn]

You'll need to chamfer the shoulder at both ends as well Julian as the compression olive pushes against them, effecting the grip.

 

[MattF]

What's it actually for Julian? Kent summed it up pretty well. There's the corrosion potential between dissimilar metals too. Compression fittings might also be fairly worthless if it may be subject to vibration.

With regard the drill bit size, Google 'BSP tapping guide'.

 

[AndersK]

19mm drill for 1/2" BSP
Most problems with those fittings are poorly tightened and failure to use support sleeves inside the copper pipe.

 

[S-Rail]

I have to agree ref the metalerigic reactions / dissimalar metals , but given most house hold heating systems have copper , steel , brass , alu and stainless in them , they do last well , you couldnt get a more eclectic mix if you tried . If the pipe and fitting is well fitted , ie ptfe etc and not tightend with a 3ft stilson it should have no problems , unless as Matt says heavy vibrations could be an issue .

Long story short many many many years ago in a galaxy far far away , I was tasked to make large incubator systems for chicken eggs and they were predominantly copper tubing and fittings , however they all ran back to stainless box / manifold sytem and we used the very fittings as I showed above , drilled and tapped into 5mm or equivealant stainless , the manifilds were made to suit out of 50x50x5mm stainless or whatever the imp equivalent is . The only problem we had was "nuggets" going to town with large adjustables .

cheers Sam

 

[julianthegypsy]

Sorry, I was at work earlier with a dreadful net connection. It's a weird thing I'm making to fit into the hot pipe from a back boiler. When it's made I will explain more
The 1/2" BSP to 15mm fittings look like they have a taper thread. The other ends are a standard compression fitting. Surely that wouldn't need a chamfer as the BSP taper locks the fitting to the block, then all the chamfers (and a compensating ring?) are already in the other end? Thanks for all the replies. It would have taken hours of banging my head against a wall on google to come up with a probably cr*p solution!

 

[Maker]

As Matt said, galvanic corrosion might be a problem, would it be possible to remake this aluminium block from brass?

 

[julianthegypsy]

As Matt said, galvanic corrosion might be a problem, would it be possible to remake this aluminium block from brass?

Really needs to be ally as I need good heat transfer.

 

[eSCHEn]

Ahh no, I'd meant you'll need the chamfer if you were making the fitting internally but thinking about that now it makes no sense lol ^_^

 

[julianthegypsy]

Ahh no, I'd meant you'll need the chamfer if you were making the fitting internally but thinking about that now it makes no sense lol ^_^

Before I had the sense to ask on here, I thought I'd have to bore it out, chamfer the end and then thread it, which sounded very likely to end in tears. Then my brain finally started working properly and reminded me to ask on here instead.