API674 is a document produced by the American Petroleum Institute that represents best practice for the provisioning of liquid pumping systems.
Measuring pressure pulsation and piping vibration concurrently enables a direct correlation to be made between the pumping frequency and the vibration frequencies of the structure. If these properties are measured independently then it is possible that minor changes in operating conditions, or atmospheric temperatures may cause difficulties in relating the two measurements because of differences in the response of the system. Making the measurements at the same time is the only way to be sure of what is happening.
Yes, hand calculations were used for many years prior to the implementation of computer based techniques. Whilst computer based techniques use many more calculations to derive their answers the fundamental physics, whether calculated by hand or computer have the same roots. However, whilst hand calculations techniques can provide some answers it is simply not possible for such methods to approach the detail and complexity of a computer based model.
Yes, "Transient Analysis" is the same thing as "Surge Analysis". the word Transient is used because a surge pressure wave is a temporary passing phenomenon, it does not last, it is...transient in nature.
A mode of vibration refers to the frequency at which a structure will resonate and the change in shape that the structure undergoes during that vibration. The first mode of vibration of a structure is often referred to as the "natural frequency" of the structure. If the frequency of vibration is increased then the structure may once again go into resonance, this would be referred to as the second mode of vibration. Further increases in the vibration frequency will reveal further modes.
The fundamental frequency for a single acting pump, where there is one discharge of liquid (sometimes called a slug) per revolution of the crank is normally taken as the number of plungers multiplied by the rotational speed of the crank in RPM divided by 60.
Yes, because there are significant differences between the capabilities of the commercially available software packages. Some software packages are excellent at network analysis, whilst others are more appropriate to component analysis rather than pipeline analysis. However, it is equally as important, if not more important to consider the experience of the engineering team that will be performing the analysis for you. Not all teams are like Flo-Dyne's where our Chief engineer has over 25 years of experience in this field.
