To keep industrial fluid systems functioning at peak performance, it is important to keep pressure-reducing regulators and back-pressure regulators working properly. The stakes are high if a regulator fails because they are integral to the proper functioning of a high-performing fluid system. Not only is it costly if fluids are accidentally released into the environment, but losing pressure as the result of regulator failure can harm system performance and present significant safety hazards.
As critical as it is to avoid these problems, preventing them starts when you are selecting and specifying regulators. During this initial process, you should ask the manufacturer what tests they run to ensure their regulators perform as intended. If regulators pass a series of robust tests, then you can be confident they will be able to withstand strenuous field conditions for longer periods of time.
The combination of engineering excellence and meticulous lab-based analysis could improve the chances that your regulators will perform as promised.
Regulator Testing Methods
The depth and breadth of regulator testing depend on the manufacturer because no single standard test exists that applies to all industries. With such variability comes differences in the thoroughness of product testing.
Consequently, when selecting and specifying regulators, consult with your supplier to confirm that products are designed and tested to meet the most stringent real-world applications. Predictive modeling may provide the theoretical framework to anticipate performance, which can then be proven using practical testing methodologies. A few of the most important tests include.
Burst Testing. Pressure regulators must maintain their integrity even when operating under high pressures. Design engineers can determine whether their products will do so by employing burst testing, which subjects regulators to pressures that far exceed the expected operational pressure. The most reliable manufacturers design their products to operate steadily under significantly higher pressures than they will see in the field.
Fluid Dynamic Testing. Consider a pressure-reducing regulator that is tasked with reducing pressure from 6000 psi at the inlet down to 100 psi at the outlet. To achieve reliable, steady pressure at the regulator outlet across a range of media flow rates, designers should make note of potential velocity traps or pressure buildup spots within the regulator. Even tiny design inconsistencies can cause a regulator to lose pressure at the outlet stream, which could mean the regulator will underperform in the field.
Computational fluid dynamics (CFD) and practical flow testing are some of the primary methods by which designers investigate pressure zones within the regulator to ensure the device is accurately sensing and thereby controlling outlet pressure per system specifications. CFD uses numerical analysis and data structures to analyze and solve problems that involve fluid flows and pressures. By identifying these potential influences on pressures and flows within the regulator, designers are better able to precisely engineer a product which can accurately control outlet pressure to meet the required set pressure of an application, which is ultimately an indicator of the regulator’s quality.
Supply Pressure Effect Testing. Inlet dependency, also known as supply pressure effect (SPE), refers to a situation in which a change in inlet pressure will directly affect the outlet pressure. When the inlet pressure increases, there will be an evident decrease in outlet pressure. In contrast, a drop in inlet pressure will result in a corresponding increase in outlet pressure.
Though SPE affects all regulators to greater or lesser degrees, it is incumbent on the manufacturer to predict and minimize it. Your supplier should be able to provide you with a chart outlining what the changes in outlet pressures will be as they relate to inlet pressure. SPE testing is used within the development process to help the designers to minimize this effect.
Life Cycle Elements Testing. Longevity of service is something operators should be able to depend on once the regulator is installed. Life cycle tests should be applied to make sure the regulator will perform as specified during the design process.
Life cycle testing can be performed as a bench test where engineers run a range of different cycle pressures, patterns, and frequencies to simulate elements of the product life cycle. Using these tests, designers can better pinpoint when and where regulators may start to fail, affecting their performance. This understanding will allow design engineers to produce regulators that can avoid these predictable wear patterns and ensure the longevity of the product.
Thermal Testing. Finally, regulators must be able to operate effectively under a variety of different environmental conditions. That is why design engineers should perform thermal testing to ensure the regulators will be able to withstand different thermal conditions.
For example, stainless steel pressure regulators are often used in general industrial applications in which they provide reliable performance under most circumstances. When extreme high and low temperatures are introduced into the equation, however, seal performance can be compromised.
Extremely high temperatures may cause some elastomeric materials to swell. In contrast, extremely low temperatures may result in materials stiffening and shrinking. In either instance, the seals will not perform as expected, leading to poor regulator performance. Thermal testing allows designers to understand and establish the limits of product capability.
What Robust Regulator Testing Means for You
The ultimate test for regulators is how they perform in real-world industrial fluid systems. In the case of pressure regulators, they should control system pressures safely and reliably and to the exact standards expected by the operators.
How manufacturers design and test their regulators will determine how well they perform. As you decide which regulators are right for you, consult with your supplier to find out the specifics of their testing process to ensure they are meeting the most stringent performance requirements. In most cases, your supplier will be able to assist you as you evaluate your pressure regulation needs and should be able to provide a solution that allows you to succeed in both the short and long term.
Dave Parkes is head of engineering for Swagelok Company at its Isle of Man ofifce.