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 […]

Continue Reading
Tags: ,

Buried Polyethylene Pipe: An Excellent Choice for Water Service

Buried steel pipe is prone to pitting due to external (soil-side) corrosion and internal (water-side) corrosion and biofouling. Preventive and mitigative measures include periodic inspection, cleaning, chemical and biocide treatments, and repairs. A cost-effective alternative consists in replacing the buried steel pipe with a non-metallic pipe, in particular high density polyethylene (HDPE). This alternative, widely […]

Continue Reading
Tags:

What is the Future of ASME B31.3, Appendix P?

Appendix P was written to introduce piping flexibility analysis rules that are more suitable for computer piping flexibility analysis, in contrast to the rules in the base Code which were written when piping analysis was done by hand calculations.  Most of the elements of Appendix P have been, or are proposed to be, added to […]

Continue Reading
Tags: ,
Becht default post image

What is Bellows Pressure Thrust?

Pressure thrust is present in all pressurized piping systems. It is simply the gage pressure times the inside area of the pipe. It acts at changes in direction, such as elbows, and at changes in pipe cross section, such as reducers. Pressure thrust is normally carried as an axial load by the pipe. However, inclusion […]

Continue Reading
Tags:

The Difference Between ASME B31.3 Appendix X and EJMA Fatigue Curves for Bellows?

Bellows vendors will often quote two different cycle lives for their bellows. One is in accordance with ASME B31.3, Appendix X. The other is in accordance with the Standards of The Expansion Joint Manufacturers Association. The latter provides a significantly higher cycle life. The EJMA bellows fatigue curve is a best fit curve based on […]

Continue Reading
Tags: ,
Becht default post image

Why is Velocity a Good Indicator of Pipe Stress Due to Vibration?

There are three characteristics of motion which are all related by the natural frequency of vibration for steady state harmonic vibration: displacement, velocity and acceleration. Of these, which is the best indicator for cyclic stress (or strain) which in turn is related to fatigue damage? As it turns out, it is velocity. One may think […]

Continue Reading
Tags: ,
Becht default post image

Changes In the 2012 Edition of ASME B31.3

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 2012 Edition of ASME B31.3, Process Piping. These changes are: Category D Fluid Service The definition was revised to include piping with design minimum temperatures below -29⁰C […]

Continue Reading
Let Becht Turn Your Problem
Into Peace of Mind