water pipe soldering

stranger12

Excellen many thanks, how long will you wait for the joint to cool down?

fezster

General advice from plumbers Ive spoken to is that they add some additional solder to yorkshire fittings. Make sure you flux properly, and the solder should flow all round the joint.

A fitting can fail at any point given enough pressure. As the incoming mains pressure fluctuates, this is always a possibility. If you live in an area with high water pressure, consider fitting a pressure reducing valve on your incoming main.

nofoollikeold

Water pressure in the UK varies enormously. There are minimum limits each water board is obliged to meet, which from memory are 1 bar and 9 litres per minute at ground level. You lose roughly 0.25 bar for storey above ground level.

Pressure testing with compressed air can be extremely dangerous. Air is compressible, so if you were to pump the pipework up to 10 bar, and suddenly a fitting gives way, all the energy in the entire system will be released in that one spot. It could send a copper fitting half way through a wall, or all the way through you.

Testing with air can be useful, as any leaks show up with dry pipes, which makes fixing the leak a bit easier. I'd suggest a maximum pressure of 1/2 a bar, with no one else in the building. Once the system is air tight, it should be tested properly with a hydraulic pump. 10 bar is too high for an all copper system, although it should withstand it. The normal pressure in a combi boiler based system is 1.2 to 1.5 bar, and the pressure relief valve should operate at around 3 bar. The standard is to test for one hour at 1 1/2 times system pressure, so say 4.5 to 5 bar. Non-combi system operate at much lower pressures, 0.5 to 1.0 bar typically, but the pipework should still be able to take 4.5 to 5 bar. Testing a system with any plastic pipework in it is different.

If you are going to pressure test, whether air, water or both, don't forget to isolate appliances like boilers, some old taps, and WC cisterns which may not be built to take that kind of pressure.

southcoastrgi

stranger12 wrote: »

Many thanks, what cofuses me is people saying I need 22mm for heating to radiator which is reduced to 15mm just before connecting it


Why would you need 22mm when your main supply is 15??

Because your mains is a totally different thing to your heating

Ainsley1

Time to cool? That depends upon the environment but long enough for the solder to solidify again -you can test if you are unsure with a thin bit of extra solder, does it melt or not - and then wait a minute or two usually at most. Do not be tempted to force cool the joint. It will be strong long before it is at handling temp.

stranger12

Thanks all

I am also changing my main water supply pipe as it is entering the house to mpde

I suppose the mpde or the plastic will be routed around the house and they have a convertor to copper

On the lead side use a universal lead to mpde connector which is compression fitting. Is that correct?

fezster

Ideally you'd upgrade the supply from the street (water meter) to the house to mdpe, to get the full benefit. You then have a mdpe to copper adapter right after your stopcock.

stranger12

Well at the moment there is a big slab ob my drive way which needs to be smashed so my thought was I changed it to the entry inside the house and later smash the concreate, dig a trench and then connect the pipe from meter to the existing mpde inside of the house