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


Effect of Heating/cooling on spring steel

Effect of Heating/cooling on spring steel

Effect of Heating/cooling on spring steel

Hi Everyone, Wondering if any body has any information on the below.

I work in a company which has a glue delivery system, within this there is pressure relief valves which are set using a spring and then air pressure to the one end which sets your 'relief' pressure, for example air pressure of 4 bar onto the pressure relief means it will activate if pressure inside the tank exceeds 80bar.

As the glue sets it becomes near impossible to clean, the only way we do this is placing the valve into an oven at 4-500c to burn the glue out of it.

I was wondering what effect this would have on the spring (spring steel) and how much it would effect its performance? (if the 4bar pressure would still give a relief pressure of 80bar, or it would weaken this significantly). Once these have been in the oven they are brought out and left to cool down at room temperature.

Any Information would be appreciated.

RE: Effect of Heating/cooling on spring steel

You need to know what stress relief temperature was used on the spring when it was manufactured.
I would expect this temp to be in the range of 250C-425C depending on the alloy.
Going above the original temp will cause relaxation of the spring.
The spring rate will not change, but the free length and travel limits will.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, Plymouth Tube

RE: Effect of Heating/cooling on spring steel

Thanks for the Reply!

For the use i am using it then, as the spring rate is the same it will compress the same amount that it would of before being placed in the oven. As the valve relies on this pressure on the spring to seal the valve until said pressure opens it, then it should operate the same, regardless of the free length of travel?

Unless the spring increases in size so much that it needs to be compressed more to fit into the valve/casing therefore giving more initial pressure on the spring before adding additional air pressure onto it?

If this makes sense to any one else?

RE: Effect of Heating/cooling on spring steel

Have you thought about using a solvent bath to clean out the glue from the spring?

RE: Effect of Heating/cooling on spring steel

I am worried about stress relaxation resulting the spring getting shorter and not applying enough force.
If the spring has any load on it when heated it will start getting shorter.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, Plymouth Tube

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!


Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close