A: There is always manufacturer lettering to prove the certification of the copper piping. It is not stamped it us usually just inked on and could possibly be cleaned off with a chemical. I would check with one piece and go from there.
A: The pieces we have do not have any stencils ... remember that copper will "green" up over time ... maybe consider coating the new tube with lacquer to maintain the shinny?
A: Type M copper is typically used in hot water heating systems. Type L copper is used in domestic (drinking water} systems. Type K copper is the best and more costly to use in all applications because it has the thickest tube wall. In a freezing environment, Pex is the way to go! Also, type M is not code approved for anything but heating. Iam a plumber and never used Type M in 38 years. Iam not a fan
A: Yes ... the draining thing is really important.
A: This is not a great area for DIY solutions. High pressures and special materials are the purview of licensed contractors. If you want to educate yourself in these areas, you might start with the Copper Development Association's Copper Tube Handbook ... https://www.copper.org/publications/pub_list/pdf/copper_tube_handbook.pdf. Getting the proper materials is only part of the solution when pressures are concerned. Skilled and experienced joints at the tube ends and fittings are critical. High a pro (with skill, experience and insurance) to handle this for you.
A: All will work at 150psi at 3/4". Check out this link for some psi range charts https://www.engineeringtoolbox.com/copper-tubes-dimensions-pressure-d_84.html
A: check your local codes, most codes require schedule 80 black pipe for compressed air installations.
A: Type M is not recommended for air line applications. Types L & K are recommended
|Name||3/4 in. x 10 ft. Copper Type M Hard Temper Straight Pipe||3/4 in. x 10 ft. Copper Type L Hard Temper Straight Pipe||1/2 in. x 10 ft. Copper Soft Type-L Coil Pipe (5/8 in. O.D.)||1 in. x 10 ft. Copper Type L Hard Temper Straight Pipe|
Buy 10 or more $21.86
Buy 10 or more $30.37
Buy 10 or more $43.33
|Nominal Inside Pipe Diameter (In.)||3/4"||3/4"||5/8"||1"|
|Product Length (ft.)||10.0 ft||10.0 ft||10||10.0 ft|
|Copper Pipe Type||Type M||Type L||Type L||Type L|
|View Product||View Product||View Product||View Product|