×
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

B31.1 Sect 114.2.3 High Temp/Pressure NPT allowance

B31.1 Sect 114.2.3 High Temp/Pressure NPT allowance

B31.1 Sect 114.2.3 High Temp/Pressure NPT allowance

(OP)
Please see code text below.
I have a flow meter welded in line.
It is SA335 P91
24" NPS Sch60 Header (.969" thick)
1/2" NPT Branch Connection used for pressure sensing
750 psig
1085 F

per 114.2.1
this connection is not allowed
unless excluded by 114.2.3

My question is, what exactly is "insertion type
instrument, control, and sampling devices" ?

Does a pressure gage fall under this category?
________________________________________________________

114.2.1
(A) Threaded joints are prohibited where any of the
following conditions is expected to occur:
(A.1) temperatures above 496°C (925°F), except as
permitted by paras. 114.2.2 and 114.2.3

(A.2) severe erosion
(A.3) crevice corrosion
(A.4) shock
(A.5) vibration
(B) The maximum size limitations in Table 114.2.1
apply to threaded joints in the following services:
(B.1) steam and water at temperatures above 105°C
(220°F)
(B.2) flammable gases, toxic gases or liquids, and
nonflammable nontoxic gases [also subject to the exceptions
identified in paras. 122.8(B) and 122.8.2(C.2)]
114.2.2 Threaded access holes with plugs, which
serve as openings for radiographic inspection of welds,
are not subject to the limitations of para. 114.2.1 and
Table 114.2.1, provided their design and installation
meets the requirement of para. 114.1. A representative
type of access hole and plug is shown in PFI ES-16.


114.2.3 Threaded connections for insertion type
instrument, control, and sampling devices are not subject
to the temperature limitation stated in para. 114.2.1 nor
the pressure limitations stated in Table 114.2.1
provided
that design and installation meet the requirements of
paras. 104.3.1 and 114.1. At temperatures greater than
925°F (495°C) or at pressures greater than 1,500 psi
(10 350 kPa), these threaded connections shall be seal
welded in accordance with para. 127.4.5. The design and
installation of insertion type instrument, control, and
sampling devices shall be adequate to withstand the
effects of the fluid characteristics, fluid flow, and
vibration.

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