Airtac PSL Throttle Speed Control Fitting PSL603B
The AirTAC Airtac PSL Throttle Speed Control Fitting PSL603B is a genuine speed controller, threaded elbow with knob with aluminium-alloy locking cap and fixed tube direction, used to set the speed of a pneumatic cylinder by throttling its air.
- TypeSpeed controller, threaded elbow
- SeriesPSL
- Working pressure0 - 1.0 MPa (0 - 10 kgf/cm2)
- Proof pressure1.5 MPa
- AdjustmentKnob with aluminium-alloy locking cap
- Temperature-20 to +70 °C
- No minimum order. A single piece can be ordered.
- Ready in 3–5 business days. That is the time we take to process the order and hand it to the carrier. Transit time after that depends on the destination.
About the Airtac PSL Throttle Speed Control Fitting PSL603B
PSL603B is an AirTAC PSL speed controller that joins a Dia 6 mm one-touch tube to a 3/8in PT male thread. It throttles air in one direction and lets it pass freely in the other, so the actuator stroke can be slowed without disturbing the rest of the circuit. The B suffix makes this the meter-in version: air flowing from the thread port out through the tube runs at full bore, while the return direction is squeezed down by the internal needle. AirTAC treats meter-out (A codes) as the first choice for double-acting cylinders, because exhaust throttling builds a smooth back-pressure cushion; meter-in like this is the right call on single-acting, spring-return actuators, where supply-side throttling gives a gentle and repeatable push.
The setting is made with a knurled knob under an aluminium locking cap: dial the speed by hand, then screw the cap down so machine vibration cannot drift it. Inside, the throttling column and body are brass seated in a PBT plastic shell with an NBR seal, and the part carries the standard PSL ratings of 0-1.0 MPa working pressure, -750 mmHg vacuum tolerance and -20 to +70 C. The tube outlet is fixed in one direction on this body style; if your routing needs a swivelling outlet at this size, note that the universal PSS body only exists at Dia 10 and 12 on a 3/8in thread.
Airtac PSL Throttle Speed Control Fitting PSL603B Technical Specifications
| Model | Airtac PSL Throttle Speed Control Fitting PSL603B |
|---|---|
| Type | Speed controller, threaded elbow |
| Series | PSL |
| Adjustment | Knob with aluminium-alloy locking cap |
| Orientation | Fixed tube direction |
| Working pressure | 0 - 1.0 MPa (0 - 10 kgf/cm2) |
|---|---|
| Negative pressure | -750 mmHg (10 Torr) |
| Proof pressure | 1.5 MPa |
| Temperature | -20 to +70 °C |
| Applicable tubing | Soft nylon or polyurethane tube |
| Thread standard | PT (Rc tapered) unless the code says otherwise |
POM release button and chuck, aluminium-alloy guide, stainless spring gasket, NBR O-ring; body brass or PBT depending on the part. A speed controller is not a shut-off valve - a small leak past a fully closed needle is normal. Close it before applying air, and turn it open slowly. AirTAC publishes flow as a characteristic curve rather than a single figure, so no L/min value is listed.
Model Code: Airtac PSL Throttle Speed Control Fitting PSL603B
| PSL | Speed controller, threaded elbow. |
|---|---|
| 4 / 6 / 8 / 10 / 12 | Tube outside diameter in mm (3.2 mm exists on the mini series). |
| M5 / 01 / 02 / 03 / 04 | Thread: M5x0.8, 1/8", 1/4", 3/8", 1/2" (M3 on the mini series). |
| A / B | A = meter-out (controls flow from the thread port to the tube). B = meter-in. |
| D | Black. Blank = grey. |
Meter-Out or Meter-In?
- check Meter-out (A) is the default. It throttles the air LEAVING the cylinder, so the piston runs against a back-pressure cushion and moves smoothly.
- check Use meter-out on double-acting cylinders - it is the one AirTAC lists as first priority.
- check Meter-in (B) throttles air ENTERING the cylinder. It suits single-acting cylinders and air motors.
- check Meter-in on a double-acting cylinder tends to give a jerky, stick-slip stroke under varying load.
- check Fit the controller at the cylinder port, not at the valve, so the throttled volume is as small as possible.
Where the Airtac PSL Throttle Speed Control Fitting PSL603B Is Used
Carton top-fold clamp
A single-acting spring-return clamp on a packaging machine closes a folding flap. Meter-in throttling slows the press stroke so the board is creased gently instead of slammed, and the locking cap holds that setting between shifts.
Reject gate kicker
A spring-return kicker cylinder flicks off-spec bottles on a filling line. The 3/8in port matches the valve block while the 6 mm bore suits the small kicker, and the B code sets a consistent flick speed as bottles pass.
Drilling jig lift assist
A single-acting lift cylinder raises a drilling jig spindle. Throttling the supply side keeps the head from snapping up when the spring releases, protecting the drill bit and the operator's hands.
Is the Airtac PSL Throttle Speed Control Fitting PSL603B the Right Part?
Dia 6 is the smallest tube AirTAC offers on the PSL 3/8in thread - the ladder above it runs Dia 8, 10 and 12 (PSL803B onwards). Choosing this code pairs a large valve port with a modest 6 mm bore, which suits a compact single-acting cylinder fed from a bigger manifold or valve block. If your valve is ported 1/4in instead, PSL602B keeps the same 6 mm tube and the same meter-in control on a smaller thread. Fit the controller directly at the cylinder port rather than back at the valve, so the throttled air volume stays small and speed changes respond immediately.
Pick B over A when the actuator is single-acting with a return spring: metering the supply gives predictable downstroke speeds. On a double-acting cylinder under a varying load, meter-in control tends to stick-slip, and an A code is the safer purchase.
Quick checklist
- ✓ Tube outside diameter matches exactly
- ✓ Thread size and standard match the port
- ✓ Working pressure within 0 - 1.0 MPa (0 - 10 kgf/cm2)
- ✓ Temperature within -20 to +70 °C
- ✓ Meter-out (A) unless you know you need meter-in
Airtac PSL Throttle Speed Control Fitting PSL603B FAQ
Working pressure 0-1.0 MPa (0-10 kgf/cm2), proof pressure 1.5 MPa, vacuum tolerance -750 mmHg, operating temperature -20 to +70 C. This SKU is the meter-in (B) PSL body taking a Dia 6 mm soft nylon or polyurethane tube on a 3/8in PT male thread, in standard grey (order the -D suffix for black).
No. A speed controller is not a shut-off valve - fully closing the needle still passes a slight leak by design, so trapped air can creep through. For positive isolation of the circuit, fit an AirTAC PHV finger valve, which is a true quarter-turn shut-off; reserve the PSL603B purely for setting actuator speed.
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