×
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

Standard for thickness of spectacle blind

Standard for thickness of spectacle blind

Standard for thickness of spectacle blind

(OP)
Hi all,

Normally ANSI B31.3 specifies formula for thickness calculation of blind. However,when we specify only pipe size, pressure rating and flange face, mostly all vendors inform the same thickness. For example, thickness of spectacle blind 10" 600# RTJ will be 2.25" (57 mm.)as per information from many vendors.

When I see standard table from many vendors, there is no standard referred for specitacle blind.

Anyone know standard applied for spectacle blind?

Thanks,

Dave     

RE: Standard for thickness of spectacle blind

Or, for a mere $58 you can own your very own copy of ASME B16.48 which, in Table 10 of the 1997 version (left the 2005 ed. at work) lists the thickness of a 10" NPS Class 600 female ring-joint figure 8 blank as... 2.25".

http://catalog.asme.org/Codes/PrintBook/B1648_2005_Line_Blanks.cfm

B16.48 takes the B31.3 formula and does the math for you. The 1997 ed. only covered carbon steel; the 2005 ed. upgraded that to cover more flavors. See the forward.

jt
 

RE: Standard for thickness of spectacle blind

or for free just build a spreed sheet with the equations something like this:

ANSI 150, 300, & 600 FLANGE SKILLET DESIGN CALCULATIONS                    
======================================================                    
                    
DESIGN PRESSURE---            720     psig
PIPELINE NOMINAL DIAMETER--        12.0     inches
PIPELINE ACTUAL OUTSIDE DIAMETER..    12.750     inches
PIPE WALL THICKNESS---            0.375     inches
PIPE INTERNAL DIAMETER..        12.000    inches
OUTSIDE DIAMETER OF RAISED FACE..    15.000    inches
"d" -max  SPAN....            13.500    inches
d = (internal + outside) / 2 = 13.5

"c" - FACTOR-----------                0.020    
"S" MAXIMUM ALLOWABE STRESS---        15,000     psi
MINIMUM REQUIRED THICKNESS SKILLET.    1.301     inches
d*(3/16*Design pressure/S)^0.5+ c  = 1.301

RE: Standard for thickness of spectacle blind

Dear members,

- Up to 24", see ASME B16.48.
- For 26" & above, use ASME B31.3 formula.

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