In OSHA’s LOTO standard (1910.147), the agency included in their definition of a “lockout device” a “blank flange” and “bolted slip blind” when in fact, these devices are actually “energy isolation devices.” So why would OSHA consider these devices a “lockout device”?
NOTE: I am not in agreement with this and have never called a “blank flange” and “bolted slip blind” a “lockout device,” but rather an energy isolation devices. This may seem like semantics, but it is HUGE in the world of energy control!
Some of the items listed in the definition of energy isolating devices (notably the blank flange and bolted slip blind) can require at least as much effort to remove as locks. OSHA believed that removing these devices, when properly bolted in place, would require wrenches to disassemble the nuts and bolts holding the blank flange or blind, and the agency saw the use of these wrenches as comparable to using bolt cutters to remove a lock. Although the wrenches used for removing the nuts and bolts from the flanges may be more readily available with a piping system than a pair of bolt cutters in the average workplace, removing the nuts and bolts would surpass the time to remove a lock. This logic about timing is just unreal, and it’s hard to believe that OSHA fell for it. Still, OSHA believed that this bolted system would provide comparable security against releasing hazardous energy in the system, even though a “lock” would not be used.
Based on the above rationale, OSHA considered bolted blank flanges or slip blinds to be an acceptable type of “lockout/tagout device”. As with all devices, these bolted systems MUST be wed as part of a standardized, documented procedure, AND they must meet the other requirements of the standard for lockout or tagout devices; that is, they must be
- DURABLE,
- STANDARDIZED,
- SUBSTANTIAL and
- IDENTIFIABLE
If bolted flanges or slip blinds are used, a means MUST be devised so that each authorized employee can be identified as a participant in the project when he/she is working on it. For example, an individual identification can be achieved by each authorized employee hanging his/her tag (or lock) on the blank flange or the slip blind when he/she starts work and removing his/her tag (or lock) when he/she stops work. In this case, the tag (or lock) supplements the blank flange or blind by identifying the employees performing the maintenance, thereby establishing a method of continuous individual accountability for the employees. An effective administrative control system, such as using a single master tag with a provision for individuals to sign in and out as they begin or end their work on the machine or equipment, would satisfy this requirement (although NOT recommended by this safety professional!).
SOURCE: LOTO Preamble