E-Stop on machinery 1

[controlnovice]

My company is selling our technology to another company. We are working with their engineering firm with us acting as 'consultants' on the design, etc.

We have in our plant, and are recommending to them, E-stops placed around each series of equipment for the operators to shut down the equipment and line.

The basic equipment setup is feeders (raw material) to extruders, extruder, cool product, cut product and package product.

Engineering firm is not installing the E-stops saying:

1) Each of the above equipment is designed by the vendor providing the equipment and has the necessary controls in their package to control that equipment.

2) HAZOP (PHA) did not identify the need for E-stops, so they are not necessary.

We feel it is protection to not just the equipment, but to personnel in the area. We do not know why it didn't show up in the PHA.

Any guidance on the necessity of hardwired E-Stops would be appreciated.

______________________________________________________________________________
This is normally the space where people post something insightful.

 

[JLSeagull]

There was a thread about this in the OSHA forum - perhaps over a year ago. I may look for it too.

Download from OSHA:

http://www.osha.gov/Publications/OSHA3170/3170-02R-2007-English.html

Safeguarding Equipment and Protecting Employees from Amputations
- Emergency Stop Devices

 

[djs]

Safety and e-stops requirements and design methods vary depending on which country you are in and what country the equipment will be used in. The European Union, in my opinion, has the most comprehensive and coherent regulations regarding personal and machine safety. Unfortunately many people take advantage of locally lax regulations with regards to human safety.

 

[JLSeagull]

HAZOP is one method of process hazard analysis pertaining to the unit operation. HAZOP addresses excursions above and below the normal conditions such as flow, pressure, level, temperature - and situations that may cause such excursions. HAZOP excludes area classification, code and standard requirements etc. A HAZOP would not catch the lack of an emergency stop pushbutton on rotating equipment.

Enforcement in the states is rare until after an accident or even until a fatality accident. Upon an industrial fatality OSHA climbs all over the place and issues hundreds of citations - but only after the accident. The engineering firm could be long gone by that time.

 

[ScottyUK]

djs correctly identifies that it is highly dependent on your location and governing codes.

If you're in the EU you may want to look at EN 954, and its replacement EN 13849-1. The latter uses techniques developed in EN 61508 and EN 61511 (which address process safety) to determine the requirements to achieve acceptable levels of personnel safety.



----------------------------------

If we learn from our mistakes I'm getting a great education!

 

[itsmoked]

There are the various logical arguments too.

An E-Stop could prevent machine damage that an observer could prevent.

Weeks of production can be lost if an injury occurs.

E-Stops are cheap insurance.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[fangas]

Questions to ask consultant.

1) This machine is eating itself. How far away do you think an E-Stop should be?

2) This machine is eating *you*. How far away do you think an E-stop should be?

Ed