Solar panel

[lucly]

hi, im from Romania and here all the pipe connections for solar panels for dhw are braze or press fitting , i hard that sum plumbers in Europe special on the petrol platforms use soft welding (Soldering)???IS IT POSSIBLE ?

[Alanka]

Of course it's possible! Why not? When done properly, a soldered joint with copper pipes will last many years.

[lucly]

ok tx for your comment

[buster]

Hi, Solar is mainly used in this county to heat domestic hot water (DHW) and most systems are supplied with most fittings because of the very, very high temperatures that can be created within a solar panel, after all the sun is the most powerful heat source in the universe. It is not recommended to use soft soldered joints because of this reason! If soft solder is used before the exchange coil there is a chance of the joint sweeting and becoming compromised or detached. But most systems are kit based so you should not have this problem! Nearly all kits are supplied with annealed pipe and not just because its easy to work with but because of 'linear expansion of materials' and the fact that most plumbers prefer not to work with low carbon steel pipe (LCS) in a domestic setting.
Buster

[Agile]

Originally Posted by Alanka

Of course it's possible! Why not? When done properly, a soldered joint with copper pipes will last many years.

Clearly Alanka has not attended a solar course otherwise he would not be giving the wrong answer!

Thats the trouble with these internet forums with anonymous posters, you have no way of knowing if they are qualified or not!

At least Buster realises the temperatures can get very high and he knows that soldered connections are not permissable but he then suggests that plastic and pushfit connections are better! I am sure that on reflection he will realise that plastic fails just over 100° whereas soldered copper can stand 300° !

Solar panels should only be connected with compression joints! Silver soldered or brazed joints would also be acceptable but are not usually practiced for heating in the UK.

Tony

[lucly]

mmmmmmmmmmmmm
I see, you are right,

[Alanka]

Thanks for your input, Agile! Apologies for misleading the forum -- indeed I have not attended a solar course, so I should not have made the comments I did.

I presumed that solar pipework, though able to get very hot indeed, would not reach anything like 300*C, and so would not affect a soft soldered joint. It is surprising isn't it!

[Paultheplumber]

Surely it would not get any hotter than the 82 degrees most boilers can reach i mean all the safety devices in terms of thermostats are there to make sure that the water in pipe work NEVER gets past 95 degrees celcius. This being because under pressure its possible for water not to turn to steam until way past 100 degrees celcius and if someone opened that temp water to atmophere they would probably die as it would instantly turn to steam. So it cannot be for temperature reasons there must be another reason for not using soft solder.

[Spirit]

The water in a solar hot water system can get a lot hotter than that. Soft solder can fail at the high temperatures and pressures. Only compression or hard solder joints should be used.