Pneumatic only Two-hand anti-tie down controls

[Latchitup]

I searched and could not find an answer.


The machine is a pneumatic press,two cylinders 32mm bore.


Can this machine be built per OSHA safety guidelines using pneumatic two hand controls with a pneumatic e-stop?
I have read some of the documentation on the OSHA website and it seems to be OK but it is kinda vague, to me. Maybe some of you guys could better explain it to a newbie using pneumatic controls and safety.

 

[iant]

yes - you will need to speak to a pneumatics Rep.
SMC, FESTO etc
There are specific Pneumatis control systems designed for safety operations.

Welcome to the site

 

[Tharon]

I really don't see why not. As long as the components meet your required safety category.

We have a few machines left that run on air logic only. While we used to have multiple, most have been phased out. It's just not efficient, and people easily messed it up by moving air hoses around. People are less likely (at least, in my experience) to move wires from terminals around than they are to move air hoses in push-in fittings.

Personally I wouldn't create any new machines using air logic only. Just like I wouldn't make one only using relay logic only. It just makes future upgrades and upkeep more complicated.

 

[iant]

Tharon - some processes can not have wiring near them - there are double handled Pneumatic valves - very dificult to repipe - as you know, it is possible to bypass any system - if you have the knowledge or the time to fiddle.

 

[Tharon]

I just remember an old hydraulic press that ran on 100% air controls. About every 2-3 weeks, it'd be down because something simple would stop working, and people on the off shifts would think "oh, this hose shouldn't be here, let's move it here, and this one here."

I'm not sure if this is a case of being unable to have wire near the process or just a case of wanting to save time/money initially by avoiding a PLC (or even smart relay, by the looks of it) and a few cables.

 

[iant]

you would be suprised as to the different complexities some machinery gets to - I have recently piped up three machines totally Pneumatic - not a bad setup.
Hydraulice with Pneumatic controls - yuck

some of the petrochem and highly explosive areas - are no go for any electrics.

 

[Manglemender]

How about two pnuematic buttons piped to pressure switches mounted in the safe zone that are, in turn, connected to a standard two hand controller?

Nick

 

[Latchitup]

Thanks for the replies!
My main concern was can it be built within the OSHA specs.
It looks like if I just mount the palm buttons in accordance with the Safety Distance formula provided by OSHA and guard the machine properly it should be ok.