The good news is that Kinetrol makes a fast acting solution purpose-built for its larger actuators. The catch is that many people don't know about it, so they reach for external booster valves, oversized ball valves, or a bigger actuator when there's a cleaner, faster option already available from Kinetrol.
If you'd rather go straight to the technical detail, the full data sheets are available to download here:
Otherwise, here's what the products do and why they're worth knowing about.
The product is the fast acting booster block, with a matching positioner block for modulating duty. Both have been available for actuator Models 16 through 60 for a while now. They just don't get talked about as much as they should, which means people keep reaching for slower, more complicated workarounds when a cleaner answer is sitting on the shelf.
What actually governs actuator speed
When it comes to fast travel times on a large actuator, the deciding factor usually isn't torque. It's air flow.
A Kinetrol actuator scales torque with size, but it also scales swept volume. A Model 60 has far more internal air space than a Model 16, so every stroke moves a much bigger slug of air in and out. The rate at which that air can flow sets the speed, and on a conventional setup the air has to travel through a standard solenoid and a length of tubing, where the flow coefficient (Cv) caps how fast things can move. The actuator itself has plenty of capability. Speed comes down to how freely it can breathe.
That's the key insight: the path to a faster large actuator runs through the air port, not the actuator body.
A quick word on how Kinetrol actuators work
For anyone newer to the brand: Kinetrol builds pneumatic rotary vane actuators. Rather than using pistons and gears to turn linear motion into rotation, a single cast vane sits directly on the output shaft inside a sealed chamber. Air on one side swings it one way; air on the other side swings it back. One moving part, basically.
That simplicity is why these units last. No rack, no pinion, no external springs to fatigue. Double-opposed polyurethane lip seals, backed by stainless expanders instead of O-rings, keep them running smoothly for millions of cycles in dusty, wet, and vibrating environments. They're a fit-and-forget actuator.
The catch has always been the same one every actuator brand faces: as you go bigger, getting air in and out fast is hard. Which is exactly the problem the booster block was built to remove.
The product you may have missed: the fast acting booster block
A Kinetrol booster block is a self-contained, high-Cv 3/2 valve that mounts directly onto the actuator's air ports. No external piping. The air path is short and wide, so the actuator fills and exhausts quickly.
The specs are worth knowing, because they're genuinely strong:
- Three block sizes, with Cv values from 30 up to 180
- A properly sized block swings a large actuator 90 degrees in about two seconds at 80% load
- Two blocks for a double-acting actuator, one for a spring-return
- A standard Namur-mount 5/2 solenoid pilot, single or dual coil, with ATEX and FM options
- A built-in restrictor for speed control and an exhaust silencer
- Tested past a million actuator cycles
If you've been speccing external booster valves to hit fast travel times on large Kinetrol actuators, this is the integrated alternative you may not have realized was on the menu.
Why it matters for shutdown and safety
Plenty of large, fast actuators end up on emergency shutdown valves, where reaching the safe position quickly is the whole job. Kinetrol built redundancy and SIL ratings into the range with that in mind. The single A block is SIL 2 capable, and the B and C blocks add built-in redundancy to reach SIL 3.
Because it all mounts compactly at the actuator with no sprawling pipework, ESD packages come out smaller, cheaper to fireproof, and with fewer leak points. For anyone putting a shutdown package together, that's a meaningful difference, and it's another reason this product deserves to be better known.
And for modulating control: the positioner block
On/off speed is one thing, but a lot of large actuators have to throttle, not just open and close. That's where the fast acting positioner block comes in, and it's just as overlooked.
It uses the same high-volume air piston approach to move air quickly, but it's engineered so the added speed doesn't cost you positioning accuracy. Standard Kinetrol Model 07 AP and EL positioners mount straight onto it, and it'll take other manufacturers' positioners through a VDI/VDE 3845 kit. Travel times run from about a second on a Model 16 up to thirteen seconds on a Model 60, all while holding position. That combination of fast and precise makes it a strong fit for safety instrumented system (SIS) functions.
Yes, you can retrofit it
Here's the part that surprises people most. You don't have to buy a whole new actuator to get this.
Order a block with a new actuator and it mounts directly to the Kinetrol air top, clean and piping-free. But booster and positioner blocks can also be retrofitted onto Kinetrol actuators already running in the field. Without the special air-top porting, those retrofits get externally piped, and a Model 60 spring return (with its spring stacked above the actuator) also needs the positioner externally piped. The point is that an existing installation isn't a dead end. If you've got large Kinetrol actuators in service that are slower than you'd like, there's a path to speed them up.
The takeaway
Big actuators don't have to be slow, and you don't have to bolt on a rat's nest of external valves and tubing to make them fast. Kinetrol's fast acting booster and positioner blocks put a high-flow valve right at the air port, cutting travel times to seconds while reducing piping, leak points, and failure modes.
These products exist today, they cover Models 16 through 60, and they can be fitted to new or existing actuators. If the only thing standing between you and a faster, safer, simpler installation was not knowing the option was there, now you do. Talk to Kinetrol about sizing the right block for your application.
For full specifications, dimensions, and ordering codes, you can download the data sheets at
