Assessing Fluid Piping Systems

Author: Ray Hardee, P.E.

I have been involved in assessing piping systems since the early 1980s and the release of our pump selection and evaluation software. The program uses electronic pump catalogs created and distributed by the pump manufacturer. With a pump rep, I made sales calls to engineering firms in Vancouver, Canada, to illustrate how they could calculate the annual operating cost for various pump models under consideration. 

Everyone we spoke to said we should show the software to the British Columbia utility company BC Hydro and their Power Smart program. At the time, BC Hydro had an incentive program to help their customers conserve electrical power through pump efficiency. They would help pay for the engineering studies and cover a portion of the costs to improve the customer’s system.  

After demonstrating the software to the utility, they requested we provide a pump system improvement training class to engineering firms and plant operators in their service area. Over the next six months I conducted multiple courses on methods to improve system operation. Using models of real-life piping systems, we demonstrated multiple ways to improve piping systems. The industries ranged from forest products, oil refining and mining to general industrial industries. 

After the course, many of the engineering firms in Vancouver evaluated their existing pumping systems using our software and shared their results. This early exposure taught me that most pumps are oversized, but plant management needs economic justification for proposed system improvements.

At that time, the U.S. Department of Energy (DOE) was focused on improving lighting systems and motor efficiency to reduce electrical power consumption. In the early 2000s, the DOE started looking at the total system, with a special emphasis on industries with high process energy costs. Concurrently, Hydraulic Institute began Pump Systems Matters (PSM), a non-profit educational foundation stressing the importance of improving the energy efficiency of these systems. In 2008, they released Optimizing Pumping Systems along with a companion course providing examples of how to perform system improvements. 

In 2009, the American Society of Mechanical Engineers (ASME) released the EA-2-2009 Energy Assessment for Pumping Systems. This standard finally established definitive requirements for conducting and reporting results of pumping system assessments. Instead of looking at individual pieces of equipment, the standard took a system approach, identifying the major areas of opportunity for the overall energy performance. 

In 2010, ASME and the International Organization for Standardization (ISO) started working together on a joint standard entitled ISO/ASME 14414 Pump System Energy Assessment, with the standard approved and released in 2015. The standard is versatile enough to be applied to both open- and closed-loop piping systems. Applications range from industrial, institutional, commercial and municipal systems, with a focus on electrically driven pumping systems. With the release of this standard, there is now an internationally recognized method for conducting assessments of pumping systems. 

What is Needed for a System Assessment

As outlined in the ISO/ASME standard, the first step necessary for a successful program is the support of facility management. They must see value in what is being proposed, and be willing to provide funding and personnel to get the program started. 

In addition, a team leader with experience in the process and various systems used is vital. An effective team leader can draw on resources from various facility departments and is mission critical to the process.

Communication is also an important part of any assessment. The scope and purpose of the system must be understood using design data, manufacturer-supplied test data and plant operating data. This documentation should be readily available. If the required documents are not available or not current, additional efforts are needed. Since these documents are also required to properly operate and maintain a piping system, these efforts will not be wasted. 

The next step involves identifying the system that has the best assessment outcome. The standard provides guidance on ways to quickly identify systems with highest probability of achieving the greatest improvement.

To assess a given system, one must first understand the current functional system requirements, in addition to determining the scope and boundary conditions for the assessment. A system walk down is performed to ensure the system has not changed over time. This is also done to gather the available design information and manufacturer-supplied test data. Finally, the operational information needed to conduct the assessment is identified and gathered. 

The actual collection of the required operating data is conducted with the aid of the operational staff to ensure the system is stable, as outlined in the assessment. 

After collecting the operational data, the final assessment report can be developed showing how the system operates and what can be done to improve the system operation.

Methods for System Improvement

The standard includes informative annexes providing recommendations and examples for conducting an assessment. Annex B provides a wealth of examples of efficient system operation and energy reduction. The system improvement can be broken down into four different approaches:

  1. Reduce system head
  2. Reduce system flow rate
  3. Operate equipment closer to best efficiency
  4. Minimize system run time

Looking at the big picture, we can see each of the above suggestions provides a way to use the system more efficiently. As always, the devil is in the details. 

Conclusion

The initial focus during the first assessments with BC Hydro, along with the early work done with the DOE and Pump System Matters, was to reduce system operating costs. During the development of the standard it became clear that assessing a piping system will not only reduce the operating costs, but it will also reduce maintenance and capital costs while increasing the overall system availability. 

To sell the idea of performing assessments on pumping systems, the first step is to determine how much the current system costs to operate. After performing the assessment, one can see ways to improve the system. The third step is to determine how much it will cost to operate the system once the suggested improvements are made. These financial models may very well be the best tools to communicate with non-engineers and management.

All my future Pumps & Systems articles will follow the method outlined in the ISO/ASME standard when assessing a pumped system so you can better understand how to assess and improve the system in your facility.  In next month’s column, we will look at additions made to a waste collection system and why the system no longer operated as designed.