15mm to 1/2 inch
- Thread starter robo
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The old imperial pipe sizes used to be standardised on the bore. Therefore a 1/2" pipe would have a bore of 12.7mm, add two wall thicknesses (of say 1mm each) gives an outside diameter of about 14.7mm.
I have never had any problem dealing with 1/2" pipe as if it is 15mm. I have soldered plenty of them with 15mm joints without any problem. The 3/4" is another story. You can use the 22mm compression joints, as long as you replace the olives for imperial ones. (I don't know if you can still buy them, but I've always manage to find one amoung my odds and s*ds when required)
btw, I have never used push fit with any imperial pipe, but I'd be highly surprised if a 15mm push fit failed on a 1/2" pipe. They are so close, the difference is negligible.
I have never had any problem dealing with 1/2" pipe as if it is 15mm. I have soldered plenty of them with 15mm joints without any problem. The 3/4" is another story. You can use the 22mm compression joints, as long as you replace the olives for imperial ones. (I don't know if you can still buy them, but I've always manage to find one amoung my odds and s*ds when required)
btw, I have never used push fit with any imperial pipe, but I'd be highly surprised if a 15mm push fit failed on a 1/2" pipe. They are so close, the difference is negligible.
B
blahblah
You can buy imperial to metric in Speedfit and copper.
Tex - you must have noticed that 1/2" inch is a bit BIGGER than 15mm od. Which means though that its wall thickness must have been more than 1.15mm, which I find surprising, as 15mm is only 0.7mm thick. Before my time so I never tried bending it!
Here's the facts about 1/2" and 15mm tube:
1/2" tube was to BS 659 and a maximum o/d was specified as 0.596" or 15.14mm, no minimum was listed but a wall thickness range was quoted - I don't have that stuff to hand.
15mm tube is to BS 2871 and has an o/d of 14.965 (minimum) to 15.045 (maximum). Normal tube for plumbing purposes is Table X (half hard temper) with a wall thickness of 0.7mm. Table Y for underground use has a wall thickness of 1mm and Table Z soft tube is 0.5mm.
Metric fittings for solder have an i/d of 15.065 to 15.145mm.
So... if you have a fitting which is at the larger end of the permitted range it will fit perfectly.
As has been mentioned 3/4" and 22mm are a different story as are 1 1/4" and 1 1/2". all other copper sizes are more or less compatible.
Nominal sizes for pipework are quoted as i/d for steel and o/d for copper.
So there.
Please don't ask me about plastic tube dimensions though!
1/2" tube was to BS 659 and a maximum o/d was specified as 0.596" or 15.14mm, no minimum was listed but a wall thickness range was quoted - I don't have that stuff to hand.
15mm tube is to BS 2871 and has an o/d of 14.965 (minimum) to 15.045 (maximum). Normal tube for plumbing purposes is Table X (half hard temper) with a wall thickness of 0.7mm. Table Y for underground use has a wall thickness of 1mm and Table Z soft tube is 0.5mm.
Metric fittings for solder have an i/d of 15.065 to 15.145mm.
So... if you have a fitting which is at the larger end of the permitted range it will fit perfectly.
As has been mentioned 3/4" and 22mm are a different story as are 1 1/4" and 1 1/2". all other copper sizes are more or less compatible.
Nominal sizes for pipework are quoted as i/d for steel and o/d for copper.
So there.
Please don't ask me about plastic tube dimensions though!
We all pay silly money for those, porks.
PTH - can you answer this one?
Nuts on compression fittings: 1/2" /15mm ones are close to 1". 3/4 / 22 are close to 1 1/4", then 1 3/4", etc. Were they ever meant to be thoise sizes?
The reason this came to light is that i decided I wanted some crow-foot spanners to fit, for tight spots. They do fit pretty well though a Snap-On 12pt 15/16" is perfect for most 15mm cap nuts, especially conex.
The okkard one is pump nuts (1 1/2" bsp) which are all just a fraction over 2 inches, about 2 1/16" No metric size is close.
I now have most sizes of crows-feet between ikkle and 2 5/8". Over about 24mm they're all imperial because few if any are made outside the States.
If anyone's perplexed they are 3/8 or 1/2 drive, to go on socket set stuff.
PTH - can you answer this one?
Nuts on compression fittings: 1/2" /15mm ones are close to 1". 3/4 / 22 are close to 1 1/4", then 1 3/4", etc. Were they ever meant to be thoise sizes?
The reason this came to light is that i decided I wanted some crow-foot spanners to fit, for tight spots. They do fit pretty well though a Snap-On 12pt 15/16" is perfect for most 15mm cap nuts, especially conex.
The okkard one is pump nuts (1 1/2" bsp) which are all just a fraction over 2 inches, about 2 1/16" No metric size is close.
I now have most sizes of crows-feet between ikkle and 2 5/8". Over about 24mm they're all imperial because few if any are made outside the States.
If anyone's perplexed they are 3/8 or 1/2 drive, to go on socket set stuff.
Chris R, My old 'copper' catalogues are at home so I will check later but the trusty Mucklow book gives 1.04" or 51mm for a 1 1/2" hexagon bush.
Am I right in thinking that pump unions are octagonal rather than hexagons and that you are supposed to use odd-legs or pump pliers to undo them. It may be that they are an odd size to discourage people from using open ended spanners and applying too much torque to the smaller flats.
When compression fittings for plumbing came out (in the 1950's?) I suspect that the two main manufacturers, Wednesbury and Yorkshire used their own sizes but these have become standardised. Have you noticed that some older 1/2" fittings are 1" across flats and newer ones are 15/16"?
Fittings manufacturers used to sell spanner sets so it would have been in their interest to make odd sizes, or am I just too cynical.
Am I right in thinking that pump unions are octagonal rather than hexagons and that you are supposed to use odd-legs or pump pliers to undo them. It may be that they are an odd size to discourage people from using open ended spanners and applying too much torque to the smaller flats.
When compression fittings for plumbing came out (in the 1950's?) I suspect that the two main manufacturers, Wednesbury and Yorkshire used their own sizes but these have become standardised. Have you noticed that some older 1/2" fittings are 1" across flats and newer ones are 15/16"?
Fittings manufacturers used to sell spanner sets so it would have been in their interest to make odd sizes, or am I just too cynical.
"book gives 1.04" or 51mm for a 1 1/2" hexagon bush. "
was that 2.04 or 1.04 x 2?!
There's still the Conex spanner, in case anyone doesn't know - a good design awfully produced, but well worth having.
The conex fittings are about the biggest across the flats - if they had flats, but fit a 15/16 really well because Snap-On's philosophy is to apply the pressure away from the corner a bit, so there's extra clearance at the corner, so the conex rib fits well. If you see what i mean!
Cheap pump nuts are hex still, ones in combis are often Oct.
Pegler/Prestex (who is that?) etc 15mm compression are octagonal of course. Not nice.
was that 2.04 or 1.04 x 2?!
There's still the Conex spanner, in case anyone doesn't know - a good design awfully produced, but well worth having.
The conex fittings are about the biggest across the flats - if they had flats, but fit a 15/16 really well because Snap-On's philosophy is to apply the pressure away from the corner a bit, so there's extra clearance at the corner, so the conex rib fits well. If you see what i mean!
Cheap pump nuts are hex still, ones in combis are often Oct.
Pegler/Prestex (who is that?) etc 15mm compression are octagonal of course. Not nice.
Ah yes, that should be 2.04" (these numbers are very close together and I've got big clumsy fingers).
Conex are the Yorkshire fittings with ridges on the compression nuts so I guess the Conex spanner is a crescent rigidly attached to the handle and a pivoted hook? I'm not sure that I've ever seen one and the don't show one in the BSS catalogue. Any chance of a picture - just out of curiosity?
I suppose that when most people replace a pump they would tend to re-use the original union nuts on the lockshield valves so by the time the third pump is in, (After the original Myson and the replacement SMC the new Grundfos) the flats are more like irregularities on a circle. Or do you people who do this stuff for a living always replace the L/S valves as a matter of course?
I don't think that Pegler make much themselves anymore but buy some of their valves from Hattersley so I guess they just brand fittings sourced from whoever can give them the best deal. Prestex is one of their trade names.
I didn't get a chance too check the old copper catalogues last night for dimensions but I will do if you wish.
Conex are the Yorkshire fittings with ridges on the compression nuts so I guess the Conex spanner is a crescent rigidly attached to the handle and a pivoted hook? I'm not sure that I've ever seen one and the don't show one in the BSS catalogue. Any chance of a picture - just out of curiosity?
I suppose that when most people replace a pump they would tend to re-use the original union nuts on the lockshield valves so by the time the third pump is in, (After the original Myson and the replacement SMC the new Grundfos) the flats are more like irregularities on a circle. Or do you people who do this stuff for a living always replace the L/S valves as a matter of course?
I don't think that Pegler make much themselves anymore but buy some of their valves from Hattersley so I guess they just brand fittings sourced from whoever can give them the best deal. Prestex is one of their trade names.
I didn't get a chance too check the old copper catalogues last night for dimensions but I will do if you wish.
The Conex spanner is just an open-ender which fits across the rib things on their nuts. Invaluable though, dumpy with pointy jaw-sides. Monument (?) do a cheap thing similar but pressed from plate. Conex also do a "flare nut" type, like a ring with a gap in it.
Piccy?? Hmm dunno. Ask in a plumber's merchant. About £6.
"Conex are the Yorkshire fittings " No No!! Yorkshire is a brand not a type. Yorkshire also do endfeed etc. Prestex might be IMI.
I thinkyou meant "compression" anyway! Yorkshire do compression too!
Old pump valves rerely work - so you have to drain down or use bungs or freeze. The reasonably priced modern ones are junk so it hardly seems worth fitting them - they'll leak in a few years. Some are a tenner each, which few customers would want as an extra.
Piccy?? Hmm dunno. Ask in a plumber's merchant. About £6.
"Conex are the Yorkshire fittings " No No!! Yorkshire is a brand not a type. Yorkshire also do endfeed etc. Prestex might be IMI.
I thinkyou meant "compression" anyway! Yorkshire do compression too!
Old pump valves rerely work - so you have to drain down or use bungs or freeze. The reasonably priced modern ones are junk so it hardly seems worth fitting them - they'll leak in a few years. Some are a tenner each, which few customers would want as an extra.
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