Understand the Harmonic Analysis and Ensure the Pressure pulsation comply with API 674

This presentation is prepared by Mr Deepak Sethia who is working in ImageGrafix Software FZCO, the Hexagon CAS Global Network Partner in the Middle East and Egypt. He has extensive experience on using Caesar II software and troubleshooting. The points that will be covered in this article are:

  • Introduction
  • Reviewing the Static Model
  • Creating the Harmonic lnput
  • The Harmonic Analysis
  • Result Review
  • Acoustic vibration and resonance is caused by Positive displacement pumps

Harmonic analysis considers the effect of a harmonic load being applied to the system.The load is usually applied as a sinusoidal function (Fig. 1), e.g. pressure pulsation from reciprocating equipment. Being of a cyclic nature, harmonic loading relates to the fatigue allowable of the design code, and should be considered. Care should be taken when undertaking a harmonic analysis for accuracy of input data. Information relating to existing field problems can be derived from measurement of pressure pulsation, deflection, forces, etc.

Fig.1: Introduction to Harmonic Analysis

Creating harmonic Input:

Follow steps shown in Fig. 2

Fig. 2: Steps for creating harmonic input

The effect of damping on the response:

Fig. 3: Effect of Damping

The Frequency-phase Dialog:

Fig. 4: The frequency phase dialog

Results Review:




Anup Kumar Dey

I am a Mechanical Engineer turned into a Piping Engineer. Currently, I work in a reputed MNC as a Senior Piping Stress Engineer. I am very much passionate about blogging and always tried to do unique things. This website is my first venture into the world of blogging with the aim of connecting with other piping engineers around the world.

Leave a Reply

Your email address will not be published. Required fields are marked *


Recent Content

Subscribe For Latest Updates

Signup for our newsletter and get notified when we publish new articles for free!