maintenance space guideline 1

[mobo]

This is on a vessel platform and I need to design access to get around a pipe to get a flange. I was going to use 18" since this is at the end of the platform and would not normally used for access.

 

[gr2vessels]

18" what, spanner, pipe size, space around the pipe? If 18" is the clearence under the pipe, you need very short people.

 

[pennpiper]

You are correct when you start with the 18" minimum clearance from the OD of the flange to the inside of the handrail for a dead end situation.

I said "Start with" because you might want to consider other factors. Such as:
> Geographic location - If this plant is in a far North location where the operators and maintenance people will be wearing heavy padded coveralls then you might want to add a little extra width to the platform.
> The size of the pipe and flanges being worked on - The larger the pipe/flange the larger the bolts and the longer the spud wrench. It would not be too good to have the wrench extending too far outside the platform when it slips from the maintenance guys hands and falls 100 feet and hits you on the head.
> The Operating temperature of the line in question - This will effect the presence of or absence of insulation as well as the type. Typically the flanges on Hot Insulated lines are not insulated, so the operator/maintenance person could come in contact with the surface of the hot flange. On the other hand flanges on Cold Insulated lines are insulated so the 18" you thought you had is reduced by the thickness of the insulation.
> The unknown - Close your eyes and picture yourself carrying a tool box and walking on that platform in the worst weather situation you can think of that would be appropriate for that plant. What should you consider?

 

[mobo]

Thanks for your feedback. FYI, searching the OSHA website I found references to “exit access”
1910.36(g)(2)” but nothing about walking around access requirements for maintenance areas.

 

[MJCronin]

mobo,

As a general rule of thumb, 3 feet is reasonable for any area where people may need to walk.

In tighter areas where access is rare, if you can get a man in and turn a wrench (i.e. 18 inches)would be reasonable

 

[rconner]

Interesting subject, and with some good responses. [While I would not say anything you come up with is specifically related, you may be interested in doing some searches, and also being aware of points made in some past quite detailed discussions of this and perhaps also "manways" and manholes etc. like per

http://www.eng-tips.com/viewthread.cfm?qid=173241&page=6

]

 

[sluisin]

You should also consider the space required for the tools used for the work.
If you are going to use large wrenches or special tools you need to consider this space as well (plus the space to handle the tool and the mechanic himself)