Soldering pipework

Just about to start soldering copper pipes to check valves, blower valve, pressure gauge and other hot objects as well as water tank fittings. Any advice on the two questions below would be much appreciated.

Where can I use soft solder or Comsol?

Does it matter if the tube goes into the fitting or the fitting into the tube?

Edited By JasonB on 03/02/2015 13:04:44

I would use screwed fittings on them all.

Silver solder the nipple/ferule to the copper pipe if its running on steam, going to get hot or under pressure from a pump or the steam.

Edited By JasonB on 03/02/2015 13:08:50

One point to consider, from the previous thread admittedly, if all the water boils away, what is going to generate the pressure?

Having seen this in the flesh on a 31/2 Atlantic boiler, all that resulted was a lump of hot metal, the residual pressure dropped to nothing very quickly, but of course would have resulted in a flash steam generation should any water have been injected, (This was witnessed at the time when the driver tried to pump water in using the handpump, the resultant 'flash' was coped with by the single safety, blowing off at 80 psi, and dropping back to zero almost immediately).

As it turned out, the driver, who was a novice at the time. was unaware of the very quick drop in water level that can happen on the Atlantic design and the fire was immediately dropped by his supervisor.

End result - boiler was taken off the frames, inspected and retested as per a new build,(allowing for softened copper) which it passed flying colours, and is still in service today.

Dont use Comsol on any boiler/steam fittings - nothing to back this up but its soft and doesnt flow very easily so i wouldnt ever consider using it. And use only known grades/brands of silver solder - I have bought some off ebay to the correct spec but god only knows what was in it!