Is it OK for copper pipes to touch?
Beside this, can hot and cold copper pipes touch?
Plumbing 101: Hot and Cold Water Lines Should Not Touch. This has passed the rough plumbing inspection and is ready for insulation and drywall. However, this installation can cause some issues down the road and is not a typical supply run installation.
Regarding this, can copper and steel touch?
Since copper has one of the highest galvanic numbers or nobility of the active metals, it will not be harmed by contact with any of them. It will, however, cause corrosion of the other metals if in direct contact.
Whenever you join copper water lines to galvanized steel pipe, you should be concerned about the corrosion caused by joining two dissimilar metals, called “galvanic corrosion.” An electrochemical reaction occurs that causes the steel pipe (in this case) to rust and clog up.