Why isnt copper used in hydraulic line? 1

[3amhigh]

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

 

[LHA]

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

 

[3amhigh]

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?

 

[jsummerfield]

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

 

[lilliput1]

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.

 

[3amhigh]

Thanks guys anyone else with input?

 

[btrueblood]

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.

 

[MikeHalloran]

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