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Behind the Scenes of a PMTG Project

Behind the Scenes of a PMTG Engineering Modeling Project

Engineers working at Purple Mountain Technology Group (PMTG) have been involved with a wide range of projects over the years. These projects may each have a unique industry, customer, or location, but they all have a common denominator: the analysis method used by a PMTG engineer.

A Purple Mountain project starts when a potential client reaches out for help. The client might have an opened ended question about unexpected behavior in a system, or more often they have identified a specific issue along with a likely cause.  In either case, PMTG will partner with the client to understand the system, application, and what questions the client has before moving to the engineering analysis. 

The engineering analysis begins with PMTG building a model of the system using simulation software from Applied Flow Technology (AFT). PMTG will examine system schematics, detailed drawings, or existing 3D drawings to build this model. They will also incorporate characteristic data about any tanks, pumps, valves, or other equipment in the system.

PMTG will also ask for any measured data from the system. It’s important to make sure the effectively captures the real system. Comparing results from that model to measured data from the system can help validate the computer model and give higher confidence in its predictions about unknown operating conditions or designs.

With a model developed and validated against the existing system, PMTG can begin to analyze system behavior under proposed or observed operating conditions, often in transient situations.

A common question clients pose is ‘what are the causes of the high-pressure events we are seeing and what can we do to mitigate and avoid them?’ PMTG’s analysis seeks to match observed system responses with known operating events, understand how hypothetical events may impact the system, and determine how to effectively mitigate waterhammer events.

This analysis is often performed similarly to a parametric analysis. PMTG will examine a series of variables to understand their effect on the system. They will look at:

  • Valve transients in the system to understand how effective a slower valve closure is at reducing maximum pressure.
  • Any pumps in the system to understand how different start-up or shut-down behaviors impact the system response.
  • Any existing or proposed surge mitigation equipment will interact with the system to reduce high pressures or avoid vacuum conditions and cavitation.

At the end of this analysis, PMTG will have a solid understanding of the system and how it behaves during existing and proposed operation. They will be able to propose effective strategies for avoiding or mitigating any waterhammer seen in the system.

With that knowledge, Purple Mountain engineers will meet with the client to discuss their findings and to explain the behavior they see in the system. Clients are also able to ask questions about the results and have a discussion with PMTG to better understand the system. Clients then receive a final engineering report documenting the expected system hydraulics and the existing transient behavior. This report can also detail how the client can execute a comprehensive waterhammer mitigation strategy

PMTG understands the need for discretion on any project. We have worked with high-profile industries and engineering teams to provide solutions to their most difficult system problems. Our website does not flaunt our clients and we always have the upmost respect for proprietary documents and information provided.

With almost 25 years of experience, Purple Mountain Technology Group has a proven record of working with complex hydraulic systems for diverse applications. Contact PMTG to further discuss your project needs.


Written by: Cort Hanson