×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Minimum Manway Size

Minimum Manway Size

Minimum Manway Size

(OP)
Does anyone know of a required size of a manway on a hydro-tank?  A requirement by OSHA or ASME or anyone?  I can't seem to find one anywhere.  

I know you can't go too small, but I'm trying to justify (other than good sense) why we should use a larger standard manway for our tanks.

Thanks

RE: Minimum Manway Size

Check first with the local jurisdiction.

For ASME VIII Div. 1 vessel, refer to UG-46.

For ASME VIII Div. 2 vessel, refer to AD-1020.

RE: Minimum Manway Size

It's not uncommon for hydropneumatic tanks to use the same size manways as on adjacent ground storage tanks, which will mean 24" or 30" or so, although you'd be hard put to justify this practice.  The larger manways on ground storage tanks are partly to get scaffold pieces through.

A worker with necessary safety gear needs to be able to get in and out for painting operations, and that would set the minimum size.

RE: Minimum Manway Size

MIL-HDBK-759 & ASTM F1166 list "Human Factors" Dimensions.
Also Woodson's "Human Factors Design Handbook"

RE: Minimum Manway Size

The Code specs. sizes. doct9960 is correct.You can buy these per made and to Code.

I like a nice "large" one....was inside a mud drum once with a guy who panicked stuck in the only manway out. By the time we got his coveralls and belt removed,two guys pulling outside and me pushing inside,none of us were real happy.

RE: Minimum Manway Size

Osha rules for sites that have women workers may require a larger dia manway than defined by ASME.

RE: Minimum Manway Size

davefitz,

At the risk of starting a thread tangent, I've gotta ask...why would OSHA think women workers need larger manways?  I can only imagine the spectrum of repsonses people could offer.

RE: Minimum Manway Size

I'm guessing it may have to do with squeezing past another person... less "incidental" contact required.

RE: Minimum Manway Size

If it's a 12x16 or 14x18 manway, nobody is squeezing past anybody.  And on just about any manway, you're going to have some people that can get through it and some that can't (not just from manway size, but configuration and height off the ground as well).

RE: Minimum Manway Size

I recall from 20 yrs ago, that a chemical refinery in Houston was required to replace manways with larger manways due to the issu of larger-hipped women not being able to be safely evacuated thru the smaller manways. I do not recall if it was a direct OSHA rule or implied due to a lawsuit alleging lost workplace opportunities because women would not be permitted to be promoted to certain jobs that required  access thru smaller manways.

RE: Minimum Manway Size

How'd the "larger hipped" persons get inside in the first place.
If you got in through the manway, shouldn't you be able to get out through the same sized opening?
[unless maybe it's a vat of beer or a tank of doughnuts winky smile]

RE: Minimum Manway Size

I was thinking on the women upper body then you guys cahnged to hips!

RE: Minimum Manway Size

The "Recommended Standards For Water Works" (a.k.a. The Ten State Standards), a report of the Committee of the Great Lakes--Upper Mississippi River Board of State Public Health and Environmental Managers, states under the category of hydropneumatic tanks that "where practical the access manhole should be 24 inches in diameter".  Although the "Ten States Standards" is not specifically enforced by government regulation or law, many states have adopted language from them to write their own standards and regulations for public water supplies.

S. Bush
www.water-eg.com

RE: Minimum Manway Size

All aside, you need to stay with a 24" if possible. If you drop down in size to 20" or even a an 18" remember that the nozzle neck needs to be shortened as the size decreases.
Just remember that management will want you to go through anything that you can get your head and one arm through.

The newer 17" oval manways for boilers are 100% better than the 16".

We require a 24" manway in all our vessels for safety reasons. The biggest concern is getting a stretcher or back board through the manway.

Case in point.
This requirement just paid for itself in spades during a recent turnaround where a contract employee had entered a 40' high reactor through a top 24" manway and as he got to the bottom he slipped on the bottom head and impelled himself on a thermowell that penetrated the bottom head. If it hadn't been a 24" manway the only other was out was by removing a 24" over flow line which would have required several hours of work.

RE: Minimum Manway Size

First off, we should refer in future to these as "access flanges" and not "manways".  Manways is a thing of the past and not politically correct these days.  I have supervised many trades staff of both genders.  Believe me, both genders come in all different sizes and shapes.  Some are just not suitable for entry into a vessel.  They however can be quite able to other work.
Cheers

RE: Minimum Manway Size

It's not actually a flange, though, in fact, the elliptical manways don't even have a flange.

As far as I know, the local cities still call a manhole just that.

RE: Minimum Manway Size

i would like to know what is the minimun size manhole is in a boiler?

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources