Coupling Guards 3

[clay87]

I had a question about coupling guards so I reviewed OSHA 1910.219(c), 1910.219(i), ASME 15.1, API 610 and some interpretations of these. I now have a worse understanding. Is there a good article or position paper that summarizes this for pump end-users?

Two specific questions:
1. Can a coupling guard be excluded on a pump if the pump is in a limited-access room (not locked)?

2. Do bare shafts and couplings without "snag points" require guarding? API 610 and general industry practice seem to imply anything rotating should be guarded while OSHA and ANSI don't.

 

[MikeHalloran]

A decent guard costs less than your research.
... and orders of magnitude less than what a trial lawyer will be able to extract from you if you omit the guard, no matter what any standard might say.



Mike Halloran
Pembroke Pines, FL, USA

 

[scjames]

I read through some of the OSHA stuff. It looks to me like they would require guards for rotating equipment.
From

http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_id=9847&p_table=STANDARDS

US Federal Register 1910.219(i)(2) and 1910.219(c)(2)(i) (which I suppose you have already read).

I'm no lawyer, but this seems pertinent to me:
"All exposed parts of horizontal shafting seven (7) feet or less from floor or working platform, excepting runways used exclusively for oiling, or running adjustments, shall be protected by a stationary casing enclosing shafting completely or by a trough enclosing sides and top or sides and bottom of shafting as location requires."

Although, section c explicitly talks about coupling guards, I don't think that section excuses one from this, more general, section.

My life tip: you can always exclude things, Its what happens when things go wrong that matter. A pump is rotating at least as fast and (occasionally) with more torque than a lathe... that is power to be respected.

 

[bimr]

http://www.hazardcontrol.com/factsheets/machineguarding/power-transmission

 

[stanier]

Unfortunatley trial judges take the view that if an accident happened the engineer who didnt specify a coupling guard is at fault. The technology exists to provide a coupling guard and I cannot understand a rational reason why you would not provide one. If you are obsessed with not having a guard you could fence off the machinery with chain link fencing with interlocks on any access points that disabled the pump when a gate/door was opened. Again you could put the pump room in a building but would need door interlocks , warm body sensors etc so that the pump could not operate if anyone was in the room.

Although not a lawyer I have spent many hours with them. Yuk! They dont think like engineers and charge much more.

“The beautiful thing about learning is that no one can take it away from you.”
---B.B. King

http://waterhammer.hopout.com.au/

 

[Artisi]

You can do what ever you like, provided you have deep pockets if something should go wrong, such as an accident due to no coupling guard being fitted. A judge would take the view if someone was injured then the fault is not sufficient safeguard for protection, an accident only proves the point.
That is not considering the moral side of the issue - could you live with the knowledge that you were the cause of a serious accident or even loss of life.

It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)

 

[stanier]

In olden days fatories were fitted with lay shafts attached to ceilings. Drive belts would come from the common shafts to lathes and other machines. there were instances where clothing got caught up int he belts and bodies were hurled skywards to be wrapped around said lay shafts. Also there have been accidents where peope' ties have been caught on metal being turned in a lathe. The result being the head is rapidly wound down to the metal where it was prompty decapitated.

Rotating shafts and clothing don't mix! That is why the whole guarding industry was developed.

AS 4024 cover it. There EN standards as well This presentation may be of help to you.

http://www.resources.nsw.gov.au/__d...3/marcus-punch---designing-safety-systems.pdf

“The beautiful thing about learning is that no one can take it away from you.”
---B.B. King

http://waterhammer.hopout.com.au/

 

[clay87]

Ok. You have scared me into dropping this topic.

Question 1 is a specific question about an existing large pump that is in an enclosure that people seldom enter. The coupling guard hinders our ability to collect thermal offset data (which may be ill-advised to do without a guard anyway). I guess I'm going to have to get creative.

Question 2 is a general question because we all have machines where we can (and sometimes do) contact the shaft. I.E. at stuffing boxes and between a seal and the bearing housing.

 

[stanier]

I guess you could have a procedure that includes task risk assessment, training and access by skilled operators only to do the tasks you mention. Whatever it is you have make sure it is not easy for the unskilled, untrained, ill informed to get anywhere near it.


In my apprenticeship days there was a female drill operator who climbed on her stool, un-did some bolts to a cover and put her hand in. Apparently the machine was making a noise. Well several fingers later she claimed for industrial injury and won! After that I never rely on logic & comon sense alone.

“The beautiful thing about learning is that no one can take it away from you.”
---B.B. King

http://waterhammer.hopout.com.au/

 

[KvdW]

We use perforated plate coupling guards (perforations 10x10mm square) and we paint them black not to hinder thermal imaging.

 

[MikeHalloran]

Okay, I'll try to address your specific questions specifically.

{
1. Can a coupling guard be excluded on a pump if the pump is in a limited-access room (not locked)?
}
If it ain't locked, it's open. Even if it is locked, people find a way to get in. This is particularly true in out of the way plant areas where people go to seek privacy. Just because they're not supposed to be there, doesn't mean they won't be there.


{
2. Do bare shafts and couplings without "snag points" require guarding? API 610 and general industry practice seem to imply anything rotating should be guarded while OSHA and ANSI don't.
}
Loose clothing, beards, and stupid fashion accessories like neckties can easily snag a rotating shaft even if it's smooth and featureless.




Mike Halloran
Pembroke Pines, FL, USA