Airtac PSL Throttle Speed Control Fitting PSL401B-S
SUS304 stainless variant (-S)The AirTAC Airtac PSL Throttle Speed Control Fitting PSL401B-S 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 PSL401B-S
The PSL401B-S is a meter-in speed controller: air flowing from the 1/8in thread port into the Dia 4 tube runs free, while flow leaving the actuator back through the controller is throttled. AirTAC grades this B-type control for single-acting cylinders, where pushing the supply side is the natural way to set stroke time; on a double-acting cylinder under a changing load, meter-in can produce stick-slip, so meter-out is usually the better choice there. The handle is marked B so the setting direction is obvious on a crowded manifold.
This -S variant swaps the brass throttling column for SUS304 stainless steel, with the throttling body in aluminium alloy or stainless depending on the part, so the wetted flow path suits wash-down and copper-sensitive processes. Adjustment is a knob with an aluminium locking cap: set the speed, then screw the cap down so vibration cannot drift the setting. The one-touch port accepts Dia 4 soft nylon or polyurethane tubing on a 1/8in PT thread. Ratings are unchanged from the standard part: 0-1.0 MPa working, 1.5 MPa proof, -20 to +70 C, and -750 mmHg vacuum.
Airtac PSL Throttle Speed Control Fitting PSL401B-S Technical Specifications
| Model | Airtac PSL Throttle Speed Control Fitting PSL401B-S |
|---|---|
| Type | Speed controller, threaded elbow |
| Series | PSL |
| Adjustment | Knob with aluminium-alloy locking cap |
| Orientation | Fixed tube direction |
| Body material | Stainless steel 304 (-S variant) |
| 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. Stainless (-S): SUS304 throttling column and body parts in place of brass, for copper-free environments. Ratings are unchanged from the standard version. 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 PSL401B-S
| 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. |
| -S | Stainless-steel body. |
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 PSL401B-S Is Used
PCB handling lift on a flux-clean line
A single-acting lift cylinder raising a Dia 4 pick head over a flux-cleaning station. The SUS304 column stands up to mild cleaning chemistries, and meter-in control lets the board carrier rise on a set, repeatable stroke instead of snapping up when the valve shifts.
Electroplating jig dip arm
A small single-acting cylinder lowering jigs into a plating bath in stages. Throttling the leaving flow meters the descent, and with brass removed from the throttling column the controller tolerates the acid-fume atmosphere above the tank line.
Rinse-tunnel stopper on a bottling cart
A Dia 4 stopper pin that must extend gently against moving bottles in a spray-wash zone. The stainless flow path and locking-cap knob survive frequent hose-down, and meter-in control gives the soft entry the bottle necks need.
Is the Airtac PSL Throttle Speed Control Fitting PSL401B-S the Right Part?
Dia 4 is the smallest tube on the PSL 1/8in ladder, so the only tube neighbour that exists is stepping up to Dia 6 (PSL601B-S), which gives you a larger bore and more free-flow headroom at the same thread. The step down in thread instead is M5, where Dia 4 is also offered - go M5 when the valve port or space on the actuator is tiny, stay 1/8in when you want a stiffer, more robust port. Whatever you choose, mount the controller directly at the cylinder port so the throttled volume stays small and the speed response stays crisp.
Knob versus push-lock: this PSL shape gives you a hand-set knob with a locking cap, which is fastest for commissioning and re-tuning. If adjustments must survive operators or vibration without drift, the PTL push-lock style in the same size is the harder-to-knock option, and the PSS universal variant adds a 360-degree swivelling tube if the hose approach angle is awkward.
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 PSL401B-S FAQ
It is a SUS304 stainless meter-in (B) speed controller taking Dia 4 soft nylon or polyurethane tubing on a 1/8in PT thread. Working pressure is 0-1.0 MPa (0-10 kgf/cm2), negative pressure is -750 mmHg (10 Torr), proof pressure is 1.5 MPa and the temperature range is -20 to +70 C. The throttling column is SUS304 in place of brass; adjustment is by knob with an aluminium locking cap. The -S change does not alter any pressure or temperature rating.
No. Like every speed controller in this family, it is designed to throttle flow and leaks slightly when fully closed, so it must never be relied on to isolate a circuit. For a true manual shut-off with a Dia 4 or 6 line, use the AirTAC PHV finger valve instead - PHV6A even vents the outlet to atmosphere when closed, which is useful when de-energising an actuator for service.
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