Becht Engineering Blog

In this section of the site contributing authors submit interesting articles relating to the various services, industries and research & development efforts of Becht Engineering.
Becht Engineering staff are experts in piping, and include former chairman of various ASME piping committees, including ASME B31.3. Becht Engineering performs detailed design for complex piping systems including very high temperature and pressure systems such as piping for FCC flue gas expanders and high pressure LDPE systems, as well as design, a...nalysis, troubleshooting and fitness for service evaluation of piping. More

Dimensional Control - Post Fabrication Pipe Spool QC Surveys

Dimensional Control - Post Fabrication Pipe Spool QC Surveys
With the advancements in dimensional technology, obtaining accurate measurements at the worksite has become common practice for most owners and engineering companies. New and replacement piping is being designed from behind desks without the designer visiting the worksite. This means there is no need for string lines, tape measures, or auto levels to obtain measurements or the need for notes on drawings stating “field to verify”. Despite these advancements, when it comes to the install of piping, it is still like playing Russian roulette on whether the pipe spools will fit or not. Failure rates are reported between 17% - 38% on spools inspected with these results being in the 70% range if the acceptance criteria was held strictly to industry specification. Failure stats are based on: Cause of Rejection Typical Value Industry Specification Dimensional Error +/- 1/2” 1/8” Bolt Hole Rotation 1/8” 1/8” Flange Face Deviance 1/8” 1/32” Wrong Flange...
Continue reading
7
  3965 Hits
  0 Comments
3965 Hits
0 Comments

ASME B31.3 - Substantive Changes in the 2016 Edition

ASME B31.3 - Substantive Changes in the 2016 Edition
In addition to the many clarifications, updated references to codes and standards, updates to basic allowable stresses, and added listed materials, there are several substantive changes to the 2016 Edition of ASME B31.3, Process Piping, which is scheduled to be issued on January 4, 2017. These changes are: Severe Cyclic Conditions The definition for severe cyclic conditions was changed. Old Definition: conditions applying to specific piping components or joints in which SE computed in accordance with para. 319.4.4 exceeds 0.8 S A (as defined in para. 302.3.5), and the equivalent number of cycles ( N in para. 302.3.5) exceeds 7000; or other conditions that the designer determines will produce an equivalent effect. New Definition: conditions applying to specific piping components or joints for which the owner or the designer determines that construction to better resist fatigue loading is warranted The new definition is expected to lead to a more appropriate application...
Continue reading
35
  15384 Hits
  4 Comments
Recent Comments
Don Frikken

It is not a Code requirement.

ASME B31.3 has no such requirement...it does not get into that much detail about documentation for radiographic examination. Perha... Read More
Wednesday, 21 March 2018 19:46
Don Frikken

Brother in law

For B31.3 piping, one welder can finish all of the passes for a weld.
Tuesday, 17 April 2018 19:14
15384 Hits
4 Comments

Two Rules-of-Thumb Regarding Piping Systems

Two Rules-of-Thumb Regarding Piping Systems
Have you noticed, looking at the famous ASME B31.1 support spacing Table 121.5, that the spacing between pipe supports is roughly “size + 10”, in other words, the spacing between supports on an 1 inch instrument tubing would be “1 + 10” = 11 ft, while the spacing on a 6 inch line for example would be “6 + 10” = 16 ft. There are of course exceptions, for example, to mention one, supports should be added near concentrated weights such as valves or vertical risers. A simple rule-of-thumb that was pointed-out to me years ago concerns the Class rating of flanges. The working pressure for a B16.5 flange at ambient temperature is approximately 2.4 times the flange Class. For example, the working pressure for a Class 400 flange at 100 F is approximately 2.4 x 400 = 960 psi. Referring to B16.5 for Group 1.1 (carbon steel) we read 990...
Continue reading
8
  5598 Hits
  0 Comments
5598 Hits
0 Comments

ASME B31.3 - Substantive Changes to 2014 Edition

ASME B31.3 - Substantive Changes to 2014 Edition
In addition to the many clarifications, updated references to codes and standards, updates to basic allowable stresses, and added listed materials, there are several substantive changes to the 2014 Edition of ASME B31.3, Process Piping. These changes are: Category M Fluid Service The definition was revised in the 2014 edition to provide better guidance on selection of the Category M Fluid Service designation (b) Category M Fluid Service:  A fluid service in which all of the following apply: (1) The fluid is so highly toxic that a single exposure to a very small quantity of the fluid caused by leakage, can produce serious irreversible harm to persons on breathing or bodily contact, even when prompt restorative measures are taken; and (2) If after consideration of piping design, experience, service conditions, and location, the Owner determines that the requirements for Normal Fluid Service do not sufficiently provide the leak tightness required to...
Continue reading
22
  19649 Hits
  26 Comments
Recent Comments
Don Frikken

RE:When will the 2014 edition ...

It was issued in February 2015.
Thursday, 07 January 2016 12:45
Don Frikken

2014 Edition Publication Date

The currently scheduled publication date is February 21, 2015.
Monday, 26 January 2015 12:14
Don Frikken

RE:Question

I'm not sure what is meant by "codes exam". B31.3 says it is effective six months after it is published, but a different date can ... Read More
Sunday, 01 February 2015 11:05
19649 Hits
26 Comments