Rotary Control Valves – PRESSOFLEX by Fluid Tech

Rotary Control Valves Built For Higher Cv, Tight Shutoff And Full-Stroke Control

Rotary control valves are often chosen because they’re compact, responsive and well suited to demanding process control duties. You’ll find them in mining, minerals processing, pulp and paper, petrochemical plants, refineries, power stations, water treatment works and other industrial environments where flow control can’t be left to chance.

But not every rotary valve design gives the same level of performance.

Many conventional rotary globe valves still operate on a restricted 50-degree stroke. That design has been accepted across the process industry for decades, but it creates a real engineering limitation. When a valve only moves from closed to fully open across a shortened rotation, the available flow path is compressed. This can reduce usable flow capacity, narrow the effective control window and place more demand on actuator precision.

Fluid Tech offers a stronger alternative: PRESSOFLEX, a Class VI rotary control valve with a full 90° stroke.

PRESSOFLEX By Fluid Tech

PRESSOFLEX by Fluid Tech is engineered for process conditions where standard rotary control valves often reach their limits. It combines high flow capacity, Class VI shutoff, strong rangeability and abrasion-resistant construction in one rotary control valve design.

A typical 4-inch rotary globe valve delivers around 230 Cv. A 4-inch PRESSOFLEX delivers 540 Cv.

That difference matters on real plants. Higher Cv at the same pipe size can help improve system capacity without major piping changes. It can also allow engineers to select a smaller valve while still meeting process flow requirements, depending on the application and operating conditions.

For plant engineers, maintenance teams and project managers, that creates practical value:

• Less restriction through the valve body
• Better usable flow capacity
• Stronger control authority
• Improved sealing at shutoff
• Better suitability for demanding process media

Why Full 90° Stroke Makes A Difference

A rotary control valve’s stroke affects how it controls flow. A conventional 50° rotary globe valve has less angular movement between closed and fully open. That can make control more sensitive in certain areas of operation because smaller movements represent larger changes in flow.

PRESSOFLEX operates across a full 90-degree rotation. This gives the valve a broader control arc, which supports more usable angular resolution across the operating range. It also helps the actuator maintain better authority from shutoff through to full open.

In demanding services, that matters. Processes don’t always operate under neat laboratory conditions. Pressure changes, solids, temperature shifts, friction, wear and changing flow demands can all affect valve behaviour. A valve with better control stability, lower hysteresis and repeatable positioning gives the plant more predictable performance.

This is where PRESSOFLEX stands apart from many traditional rotary control valves. It’s not just about opening further. It’s about using that full stroke properly for stable, controlled movement.

Class VI Shutoff For Critical Process Control

Shutoff class is one of the biggest differences between PRESSOFLEX and many conventional rotary globe valves.

Many rotary globe valves are designed for Class IV shutoff. Class IV allows measurable leakage at shutoff. For older plant designs, that may have been accepted. For modern process environments, especially where product loss, chemical exposure, contamination or safety concerns are involved, leakage can be costly.

PRESSOFLEX is designed for Class VI shutoff.

The valve uses process pressure itself to assist sealing. As fluid pressure acts on the flexible seat, the seat is driven harder into the ball segment. The pressure that would normally encourage leakage helps improve the seal.

That sealing principle gives PRESSOFLEX a major advantage in services where tight shutoff is required. In applications such as copper concentrators, bleach plants, chemical processing, slurry handling and other harsh industrial processes, reduced leakage can support cleaner operation, better process control and less product loss.

For engineers comparing rotary control valves, this is a serious specification point. Class VI shutoff is not a small improvement over Class IV. It changes how the valve performs at shutoff.

High Cv Rotary Control Valve Performance

Cv is a practical measure of flow capacity. When two valves have the same nominal size but very different Cv values, the impact on the system can be substantial.

PRESSOFLEX delivers 540 Cv on a 4-inch valve body, compared with around 230 Cv for a typical 4-inch rotary globe valve.

Higher Cv can help:

• Reduce pressure drop across the valve
• Improve flow potential through existing pipework
• Give engineers more flexibility during valve selection
• Support plant upgrades without major infrastructure changes
• Reduce the need to oversize valves in certain applications

This is especially useful in brownfield environments, where changing pipelines, supports and surrounding infrastructure can become expensive and disruptive. A rotary control valve with higher flow capacity can give project teams more options.

Rangeability Across A Full Control Arc

Rangeability refers to the ratio between the maximum and minimum controllable flow. Conventional rotary globe valves are often associated with 100:1 rangeability. PRESSOFLEX is engineered for 500:1 rangeability.

That figure becomes even more meaningful because it’s applied across a full 90° stroke, not a compressed 50° movement.

A broader control arc gives the valve more room to regulate flow accurately. That can help in processes that require stable low-flow control as well as high-capacity operation. For plants with changing production conditions, variable loads or difficult media, this additional control range can make a clear difference.

Precision only helps when the valve has enough usable flow envelope to work with. PRESSOFLEX gives engineers that broader envelope.

Built For Abrasive And Aggressive Media

Industrial process valves often fail because the real media is harsher than expected. Slurries, fibres, particles, scale, chemicals and abrasive flow can wear trim surfaces, damage seats and reduce control accuracy.

PRESSOFLEX is built with 316 stainless steel and Tungsten Carbide trim. Tungsten Carbide offers very high hardness, around 1,500 HV, making it highly resistant to abrasion and erosion.

This makes PRESSOFLEX well suited to aggressive services where standard valve trim may wear quickly. For mining, pulp and paper, minerals processing, power generation and water treatment, material selection isn’t a minor detail. It directly affects service life, maintenance frequency, plant availability and long-term valve performance.

A valve that controls well on day one must still control well after months of service in real process conditions. That’s the standard PRESSOFLEX is built around.

Performance At A Glance

PRESSOFLEX gives engineers a clear performance comparison against many conventional rotary globe valve designs:

• Class VI shutoff versus Class IV shutoff
• Full 90° stroke versus restricted 50° rotation
• 540 Cv on a 4-inch valve body versus around 230 Cv
• 500:1 rangeability versus typical 100:1 rangeability
• 316 stainless steel body with Tungsten Carbide trim
• Strong resistance to abrasion, erosion and aggressive media

All figures are based on a 4-inch valve body. Test conditions are available on request.

Spring-Return Rolling Diaphragm Actuation

PRESSOFLEX uses a true 90° spring-return rolling diaphragm actuator. This gives process engineers the control philosophy they already trust, while supporting the full 90° movement required by the valve design.

For many plants, this makes adoption easier. Teams don’t need to rethink the whole control architecture or train operators on an unfamiliar actuation method. PRESSOFLEX fits into familiar process control thinking while giving better flow, better shutoff and stronger stroke performance.

That’s valuable for projects where reliability, maintenance practicality and plant acceptance all matter.

Where PRESSOFLEX Rotary Control Valves Are Used

PRESSOFLEX rotary control valves are suited to tough industrial services where flow control, shutoff and wear resistance are all important. Typical sectors include:

• Mining and minerals processing
• Pulp and paper
• Petrochemical and refining
• Power generation
• Water and wastewater treatment
• Chemical processing
• Slurry and abrasive media handling
• Industrial process plants

These environments quickly expose weak valve designs. Poor sealing, restricted geometry, trim wear and limited flow capacity don’t stay hidden for long. PRESSOFLEX is designed for these realities.

Choose Fluid Tech For Rotary Control Valves

Fluid Tech supplies process control valve solutions for demanding industrial applications. With PRESSOFLEX, Fluid Tech gives engineers a rotary control valve that challenges the old 50° limitation and delivers measurable performance advantages.

You get Class VI shutoff, full 90° stroke, high Cv, 500:1 rangeability and durable Tungsten Carbide trim in a valve built for real process conditions.

If your plant is still specifying rotary globe valves by habit, it may be time to compare the numbers.

Speak to Fluid Tech about PRESSOFLEX rotary control valves and find out how the right valve selection can improve flow capacity, sealing performance and control stability on your process.

Are we specifying based on performance, or on habit?

PRESSOFLEX

The only Class VI rotary control valve with full 90° stroke.

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