×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Why isnt copper used in hydraulic line?

Why isnt copper used in hydraulic line?

Why isnt copper used in hydraulic line?

(OP)
Could someone explain to me why either copper, zinc, or cadmium is not to be used in hydraulic systems?  I've heard of copper fittings, valves, ect. used but why not pipes?  Is it due to the brittleness or oxidation?  TIA

RE: Why isnt copper used in hydraulic line?

Cu and An are very soft, I don't know about Cd...hydraulic systems tend to undergo extreme and repeated transients of temp and pressure.  I think that is why.

Remember: The Chinese ideogram for “crisis” is comprised of the characters for “danger” and “opportunity.”
-Steve

RE: Why isnt copper used in hydraulic line?

(OP)
Thanks, thats what I have found thus far, they tend to get brittle and fail.  But why is it that Cu can be used for refrigeration?  Is there some type of corrosive reaction between hydraulic systems that cause excessive wear on the pipes? I know some fluids contains sulfur and zinc does this have anything to do with it?  

RE: Why isnt copper used in hydraulic line?

Hydraulic lines are often high-pressure such as 3000 psig.  This requires stronger materials than copper such as steel or stainless steel.

Cadmium is a heavy metal with environmental impact at the manufacturing facilities.  Zinc, Cadmium and non-metalic coatings are common for corrosion control.  Cadmium would be unusual for piping or tubing.

John

RE: Why isnt copper used in hydraulic line?

Hydraulic lines are very high pressure. Less than 20000 psig is considered medium pressure & above 20000 to 50000 psig is high pressure. See Autoclave & Butech catalogs for hydraulic valves & fittings.

RE: Why isnt copper used in hydraulic line?

(OP)
Thanks guys anyone else with input?

RE: Why isnt copper used in hydraulic line?

Generally speaking, there's no obvious reason not to use copper alloys, other than cost versus strength.  It's cheaper to get the required strength (and corrosion resistance if required) in steel than in copper alloys.

RE: Why isnt copper used in hydraulic line?

Copper doesn't have great fatigue resistance.  Refrigeration systems generally run at stable pressures.
Hydraulic systems almost always have severe and recurrent pressure transients.


Mike Halloran
NOT speaking for
DeAngelo Marine Exhaust Inc.
Ft. Lauderdale, FL, USA

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources