A structured approach to smarter valve selection

Across the severe service industries, IMI is known for excellence in problem-solving. With an extensive portfolio of products built on decades of experience, we can address any flow control challenges, from the simplest to the most demanding.

Often overlooked is the fact that our portfolio includes some of the simplest valves for everyday applications. From butterfly and ball valves for reliable shutoff to custom-engineered control valves for specialised service, all IMI products are designed to provide the same level of quality, longevity and reliability.

Selecting the appropriate valve from an extensive technology portfolio requires technical understanding and honest partnership. An under-specified solution risks operational failures, safety issues, and costly shutdowns and repairs. Over-specify, and you invest in a product with extensive capabilities that you’ll never use.

Valve Tiers classify products by engineering complexity. At IMI, our Tiers range from simple, everyday valves to advanced solutions for extreme conditions. Our Tiering approach makes it easier for you to choose the correct valve that is reliable, efficient, and fit-for-purpose.

#ChooseTheRightValve is a new series aimed at introducing you to the IMI valve portfolio, from our foundational Tier 1 butterfly and ball valves to our most sophisticated Tier 6 solutions. Our engineering experts design the higher-Tier products to solve highly specific or demanding challenges in some of the world's most high-pressure industries and technical plant applications.

This new technology-focused series will explore how valve performance has been enhanced, with a Tier added each time a new challenge or control barrier is introduced. It also highlights the side paths that have led to some of our innovative solutions for persistent customer challenges, such as clogging caused by entrained solids, including our Metamorphic Trim.

We’ll look at the challenge of differentiating between products that appear to fulfil the same function. And we’ll help you better understand when to consider upgrading to the next Tier of solution rather than replacing like-for-like, under the premise that ‘better the valve you know’ is not automatically time or cost-effective.

Our advanced flow control management technologies have emerged over decades, through purposeful design and, in part, through the merging of brand product lines. Every variant has been developed to address a specific need, such as withstanding extreme pressures or corrosive liquids, reducing noise output to protect personnel, managing solids within the flow, or simply ensuring tight shutoff.

Our customer-driven approach has created a comprehensive product range that ensures there is a solution for every issue, of the right size, and not over-engineered. Or, in other words, we don’t need to over-engineer the required solution.

As mentioned above, to navigate this series, we’ve broken our product range into Tiers. This Tiering framework isn’t an indication of quality or based on price. It reflects the level of complexity and sophistication of the engineering challenge the product solves.

Tier 1 solutions would include butterfly and ball valves, which are no less essential in the smooth running of a plant. Butterfly valves are designed to provide a reliable shut-off. Properly designed butterfly valves minimise wear between their moving parts, thus mitigating a potential path for future leakage. For example, the IMI Orton MV Triple Eccentric design eliminates friction between the disk seat ring and the seat while maintaining a tight shutoff environment.

Ball valves are typically used for simple flow control, though among our valve solutions, we also offer more precise flow control options. For instance, our Tier 1 IMI Truflo C-Rex ball technology features a contoured flow passage. This is similar in function to the 840G valve in Tier 2, but without the same flow control, giving the user an option between greater flow control and a more compact, economical ball valve design.

Ported cages at Tier 2 achieve a single-stage pressure drop across a range of designs and geometries. The common feature is that the flow is controlled by a variable-area, single-stage orifice. A Tier 2 port cannot compare to a Tier 3 port in trim levels, but each Tier 2 port brings something unique: a geometry that offers greater economy in a smaller design, or one that is better for liquid service, while another performs best in gaseous service.

There are fewer geometries available in a drilled-hole cage (Tier 3), though variations are possible. At this level, the aim is greater flow control or reduced noise. While drilled-hole cages utilise fewer trim geometry varieties, a near-unlimited combination of hold patterns means these Tier 3 valves can provide any desired control characteristic.

However, when the pressure drop across a single-stage cage increases, noise and flow control issues worsen. In a Tier 4 design, we break the pressure drops into several steps based on factors such as fluid vapour pressure or molecular weight.

Manufacturing concentric cages eventually becomes impractical. As the number of required stages and pressure drops increases, new technology is needed to meet the challenge in a smaller, more economical, and more efficient package.

Over the years, we have developed many different manufacturing techniques for our Tier 5 solution, the multi-stage DRAG™ trim. This includes electrical-discharge-machining (EDM) etched disks, stacked punched disks, and stacked laser-cut disks. Each has merit over a certain range of sizes and strokes. With traditional DRAG™ manufacturing practices, it is possible to achieve upwards of 30 stages of pressure reduction in a practical size and volume, and they can be customised to any required flow control characteristic.

Yet even those manufacturing techniques have their limits. Our Tier 6 valves utilise trims manufactured via additive manufacturing (AM), which enable tighter packaging of stages and flow passages, more complex passage geometries, and simpler manufacturing of flow paths.

This highly innovative solution has been implemented as an AM 3D disk stack featuring a custom upside-down V-shaped flow path that uses vertical space within the trim rather than relying solely on the limited radial wall thickness. This enables 10 expanding stages to control velocity effectively and provides a larger inlet flow area, reducing the risk of particle buildup and clogging. Notably, this cannot be done with a Tier 5 solution.

Our Tier 6 designs are innovative solutions to unique situations and represent our decades of engineering expertise and problem-solving excellence. They are also complex and highly specialised.

When your requirement is for a simpler product, that is what we deliver. Our engineers work with you to understand the issue at hand, whatever the size, review your current valve to determine the cause and, where needed, challenge assumptions.

By discussing technical specifications, operational context, maintenance, and budget constraints, we work with you to deliver the solution that fits. We offer you an investment in capability and longevity that is right-sized, not over-engineered, or inadequate for the task.

In this technology-focused series, we will consider our wide range of solutions and explore the methodology our engineers follow in assessing specific needs and operational requirements. For us, our portfolio engineering isn’t about complexity. It’s about working with our partners to find appropriate, effective solutions.

To discover more about our flow control technologies, please visit our company page.