A dehumidifier is a device for the removal of moisture from the air. The copper pipe that is not connected is almost certainly a drain pipe. As the dehumidifier removes moisture from the air, it has to collect and then drain in some way. A drain pipe would handle the latter chore. Consult the manufacturer or a distributor for a manual or just some information.
When I have to connect copper to lead "D" I usually solder the copper to the lead or wipe a lead joint depending on the diameter To connect copper to cast iron ,.... If there is a hub I caulk the copper directly into the CI with oakum and poured lead (molten) OR one can solder / braze a female adapter fitting and screw the copper into a CI female fitting
Easiest way to connect lead to copper /brass is a wiped joint consisting 40 - 60 solder alloy as this gives a longer pasty range
YOU thread or braze copper pipe Copper tubling you solder, braze, flaire, compression ring, mechincal joints
Yes
In order to connect a chromed steel pipe to a copper pipe, you will need a brass fitting. These two pipes will not fit into each other otherwise.
It is probably referring to the type of fitting. A fitting that is soldered to a copper pipe. It is called sweating when you use solder and a torch to connect copper pipe together or attach fittings to copper pipe.
NO but you will need some type of sealent OR braze or soldering
Flare copper pipe and use a flared shutoff valve. If valve isn't flared, use an adapter fitting between copper flared pipe and valve.
If you do connect copper pipe to galvanized pipe, you will need a dielectric coupling or else the galvanized pipe will corrode. Same with connecting galvanized pipe to brass fittings. Brass is an alloy that contains copper and therefore the same electrolytic properties will exist unless a dielectric coupling is used. Hope that helps you out.
If you had been advised why ask again?
You can often find a modern connector such as Sharkbite or Qwest fitting to do this.
Yes, you can either solder them or fit mechanical (threaded) fittings.