solder a bracket to a brass pneumatic fitting?

[Bruceb]

Is it legal to solder a bracket to a brass 3 way fitting so it can be mounted to my chassis or is soldering considered "altering"?
Big Al. I would appreciate your insight here.
Thanks

[MrForbes]

I don't know the legality (only the GDC does), but it sounds like something that would cause inspection problems. How about making a bracket that clamps to the fitting? Or the good old standby of zip ties...

[Jon Stratis]

I would consider that altering. When soldering to brass, there's no way for an inspector to know how hot the material got, or if the integrity of the fitting was compromised. The last thing we want is for the fitting to blow out and either reduce your robot performance on the field or injure someone nearby (granted, I think this is a much lower likelihood given this particular situation).

Personally, I would just zip tie the fitting in place and call it good.

[Bruceb]

well just a zip tie wont work as it is part of the guage, pressure release valve, etc but I guess I can mill a clamp or something.
Thanks for the feedback.

[MrForbes]

We usually try to mount that stuff to the compressor and to the regulator, generally about half on each, then it has something solid to hold it. Alternatively you can use quick connect fittings and plastic TEEs instead of brass TEEs, then zip ties don't have to deal with as much weight.

[ebarker]

If I were inspecting, I'd flunk that. That is an alteration of a part. Sorry

[Chris Endres]

As someone stated before, zip ties work just as well. You can make the bracket to connect to your chassis, then drill holes out and feed strong zip ties through to connect each end/side of the fitting. This substitutes the illegal soldering.

[JamesCH95]

Epoxy wouldn't work?

[jvriezen]

Originally Posted by JamesCH95

Epoxy wouldn't work?

As an Inspector, the soldering would definitely raise questions, and Epoxy would probably make me call the LRI (if I noticed it). I don't know enough about the possible chemical reactions between whatever form of epoxy used and brass to know if there is risk of compromise.

[DonRotolo]

I'd also flunk that, also with epoxy.

[Al Skierkiewicz]

You may not modify pneumatic parts. A famous vendor from Kokomo was reminded of that at Champs two years ago.

[IndySam]

Originally Posted by Al Skierkiewicz

You may not modify pneumatic parts. A famous vendor from Kokomo was reminded of that at Champs two years ago.

After I warned him!

[JamesCH95]

Originally Posted by DonRotolo

I'd also flunk that, also with epoxy.

Why would you flunk a fitting that has been glued in place?

Would VHB or a double-stick tape be okay in your opinion?

[Tristan Lall]

Originally Posted by JamesCH95

Why would you flunk a fitting that has been glued in place?

Would VHB or a double-stick tape be okay in your opinion?

It's the usual problem of whether adhesive fastening should be considered a violation of the rule that "[a]ll pneumatic COMPONENTS must be used in their original, unaltered condition" (with exceptions).

Given that adhesion is inherently an interaction between surfaces that (on an atomic level) leaves neither unchanged, there's a case to be made that every adhesion is an alteration. On the other hand, plenty of other things (like simple contact) involve changes at that level, and wouldn't conventionally be called alterations.

FIRST would probably be concerned with the use of solvent-based adhesives on polymer substrates (high risk of error leading to failure, e.g. of a crazed pneumatic tank), or of installations that impose unforeseen loads (e.g. using epoxy to mechanically fasten a dynamic component to the side of a pneumatic cylinder). They probably wouldn't be concerned about masking tape holding a pneumatic tube out of the way, or about normal wear and tear incurred during a short working life. But the rules don't offer a specific basis upon which to distinguish these cases, so absent clarification from the usual official sources, it's going to come down to the officials at each event and their interpretation of the rule.

I think it will be hard to set and enforce a consistent standard using the rule as written, because alteration is easy to find if you're looking. If that's true, a rule update (possibly in the form of some more exceptions) would be preferable to a Q&A response (which can't change the fundamental constraint concerning the "original, unaltered condition").

[Al Skierkiewicz]

Tristan, I am relating the standard rubric that inspectors are trained to make decisions in the field based on the rule and the inspection checklist.

____ No Modifications - pneumatic parts may not be modified except actuator mounting pins may be removed. <R76>