Addressing Gusset Problems: Pipe Cracking Part 2

By Del Underwood at Det Norske Veritas, and Tim Munsterman at Det Norske Veritas. This article appears in the January/February 1996 issue of Inspectioneering Journal.

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Gussets

Gussets, sometimes known as gusset plates, are metal sheets of various thicknesses used for either joining two or more components together or strengthening joints. These components include beams, girders, truss members, chords, and columns. They can also be used to retrofit...
Mechanical Integrity (MI)

Mechanical Integrity (MI) can be defined as the management of critical process equipment to ensure it is designed and installed correctly, and that it operates and is maintained properly (i.e. no leaks and all elements are fit for service). A mechanical integrity program should...
Piping

In every processing facility, you have feedstock and product that need to get from point A to point B. Piping is the vehicle that moves these liquids and gasses through a refinery or chemical processing plant. They can be made of steel, cast iron, copper, plastic, or...
Process Equipment

Much of the equipment used in the refining and processing industries is known as Process Equipment. Most pieces of process equipment are designed to perform specific, singular tasks. Process equipment can be used for tasks as varied as storage, controlling flow, and...
Welding

Welding is the process of joining separate materials, usually metals or thermoplastics, using extreme heat. Welding is an ancient trade that has been around for thousands of years, and it is one of the most important and widely used manufacturing processes in the...

Addressing Gusset Problems: Pipe Cracking Part 1

September/October 1995 Inspectioneering Journal

A key to any piping evaluation program is to understand where problems can occur. Vibrating piping can propagate a crack relatively quickly. Have you ever installed gussets to stabilize a vibrating pipe situation only to find, shortly thereafter,...
Tangential Radiography Technique for Special Weld Joints Configuration

January/February 2008 Inspectioneering Journal

Most common radiographic practices for circumferential weld testing are single wall and double wall techniques with certain variations in technique details. Different Codes deal with the number of exposures required and applicability of the...
Making the Most of Storage Tank Inspection Data

January/February 2012 Inspectioneering Journal

Thanks to constantly improving technology developments, inspection of atmospheric storage tanks has yielded better data which, when used as input, improves the accuracy of advanced assessment techniques. Coupling the improved inspection data with an...

This article is part 2 of a 3-part series.

Part 1 | Part 2 | Part 3

Last issue, in keeping with the evaluation that "gussets are stiffeners, not strengtheners", we discussed welding around the ends of the gusset plate instead of just along the sides in order to reduce the stress concentration. A further improvement in the gusset life can be obtained by welding it to a reinforcing plate and/or a fitting instead of directly to the pipe.

One common situation is shown in Figure 1. Because of the pendulum action of the heavy valve under vibration, high stresses are encountered at the ends of the gussets, as shown. Even though the life of the joint has been improved by continuing the full strength weld around the ends, cracks in the pipe can still be encountered.

In Figure 2, the reinforcing plate around the nozzle has been enlarged so that the gusset is attached to it, instead of the line. At the other end, it is welded to a valve flange. It is important to position the gussets so that they do not interfere with fitting a wrench over the flange blots for assembly and disassembly.

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