Written on February 1, 2011 at 10:43 pm, by Joe Honeywell
Introduction Confusion sometimes results when reviewing published NPSHR curves. This is especially true when faced with trimming the impeller diameter to match changing operating conditions. A well known fact is that the head-flow relationship varies with the diameter. This can be accurately approximated by the affinity laws. However, what happens to the NPSHR-flow relationship whenContinue Reading
Written on September 1, 2010 at 9:51 pm, by Joe Honeywell
This is the final part of a two part Tip of the Month (TOTM) series on important aspects related to centrifugal compressor performance testing. The first part dealt with the review of the testing procedure presented in ASME PTC-10 (also referred to as the Code), selection criteria for test gases and factors to consider inContinue Reading
Written on August 1, 2010 at 9:03 pm, by Joe Honeywell
Every centrifugal compressor, whether it is new or has been in service for many years will most likely be tested to verify its thermodynamic performance. For a new machine the testing may be conducted in the manufacturer’s facility under strict controlled conditions or in the field at actual operating conditions. Older compressors that have beenContinue Reading
In the August 2009 Tip of the Month (TOTM), it was shown that pumping power requirement varies as the crude oil °API changes. Increasing °API or line average temperature reduces the crude oil viscosity. The viscosity reduction caused higher Reynolds number, lower friction factor and in effect lowered pumping power requirements. Since the objective ofContinue Reading
During the life cycle of a crude oil pipeline the properties of transported oil change, because in gathering systems the produced oils come from different wells. New wells may be added or some wells may go out of production for maintenance and repair. Production rates during the life of wells vary, too. In addition theContinue Reading
Written on May 1, 2009 at 10:07 pm, by Joe Honeywell
One of the most important physical properties of a gas is the ratio of specific heats. It is used in the design and evaluation of many processes. For compressors, it is used in the design of components and determination of the overall performance of the machine. Engineers are frequently asked to evaluate a compressor performanceContinue Reading
In the February 2007 tip of the month (TOTM), Joe Honeywell [1] presented a procedure for calculating fluid pressure drop for liquid in a piping system due to friction. Continuing Honeywell’s TOTM, we will outline procedures for calculation of friction losses in oil and gas pipelines. From an engineer’s point of view the question may arise “howContinue Reading
In this tip of the month, we will discuss how miscalculations and incorrect analysis of potential process upsets can affect process safety. There are many aspects in facility design engineering and process safety engineering that should be considered when designing a new facility or debottlenecking an existing one. During these times of compressed schedules andContinue Reading
In this tip of the month (TOTM) we will present the results of several case studies showing the effect of gas molecular weight on the performance and efficiencies of centrifugal compressors. We have considered several “what if” scenarios such as variation of compressor speed as a function of molecular weight, while maintaining the same suctionContinue Reading
Written on February 1, 2007 at 9:13 pm, by Joe Honeywell
Introduction Engineers are frequently asked to calculate the fluid pressure drop in a piping system. Many software programs are available for solving complicated hydraulic problems; however’ they can be complex and difficult to use. In addition, there are many tables or shortcut methods that give adequate answers but they usually apply to predefined conditions whichContinue Reading
