Airtac PSL Throttle Speed Control Fitting PSL603B-S
SUS304 stainless variant (-S)The AirTAC Airtac PSL Throttle Speed Control Fitting PSL603B-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 PSL603B-S
The PSL603B-S is the SUS304 stainless-steel version of AirTAC's PSL thread-in speed controller. It screws into a 3/8in PT port, takes Dia 6 soft nylon or polyurethane tubing on the outlet, and sets actuator speed by throttling the air in one direction while the opposite direction passes unthrottled. The B suffix means meter-in: air flowing from the thread port into the tube runs free, and the return path is restricted. Meter-in is the right choice for single-acting cylinders, where there is no exhaust back-pressure to cushion the stroke.
Adjustment is a brass-pattern knob layout built around a SUS304 throttling column with a stainless spring gasket, topped by an aluminium-alloy locking cap so the setting holds under vibration. Because the wetted flow path is stainless rather than brass, the part suits copper-free and corrosive areas such as plating lines and wash-down zones. Pressure, vacuum and temperature ratings are identical to the standard PSL603B - stainless changes the material, not the performance envelope.
Airtac PSL Throttle Speed Control Fitting PSL603B-S Technical Specifications
| Model | Airtac PSL Throttle Speed Control Fitting PSL603B-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 PSL603B-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 PSL603B-S Is Used
Plating line lift probes
Single-acting lift cylinders that raise electrode jigs out of acid baths need controlled lowering without brass in the splash zone; the SUS304 flow column and meter-in restriction suit that duty.
Wash-down tray indexer
A food-line pusher indexing trays between wash and fill stations runs on Dia 6 tubing from a compact valve manifold; stainless construction survives daily caustic rinse-down.
Marine hatch hold-down ram
A salt-air deck mechanism clamping inspection hatches uses meter-in control on a single-acting ram so the clamp closes at a set pace; stainless internals resist the corrosive atmosphere.
Is the Airtac PSL Throttle Speed Control Fitting PSL603B-S the Right Part?
Meter-out (A suffix) remains AirTAC's stated first priority for double-acting cylinders because exhaust throttling creates a back-pressure cushion; pick this B-coded meter-in part when the actuator is single-acting or when an extend stroke must be fed against a light, constant load. A knob with a locking cap sets faster by hand than a push-lock cap and can be re-trimmed on the line, while push-lock designs resist accidental disturbance - choose by how often the speed is changed.
On the 3/8in thread ladder Dia 6 is the smallest tube AirTAC offers, so there is no size below it on this thread; the next step up is the PSL803B-S with Dia 8 tubing, which gives you a larger bore and correspondingly higher capacity on the same port. If your machine plate calls for a smaller port, PSL602B-S (1/4in) and PSL601B-S (1/8in) both exist for Dia 6, but note Dia 6 is not offered on 1/2in PSL bodies. Mount the controller directly at the cylinder port so only the short port volume is throttled.
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-S FAQ
It is a SUS304 speed controller with Dia 6 tube and 3/8in PT thread, meter-in (B) control. Working pressure 0-1.0 MPa (0-10 kgf/cm2), negative pressure -750 mmHg (10 Torr), proof pressure 1.5 MPa, operating temperature -20 to +70 C. It runs on soft nylon or polyurethane tubing and the knob carries an aluminium-alloy locking cap over the stainless throttling column.
No. A speed controller throttles by design and still passes a slight leak when fully closed, so it must never be relied on to isolate a circuit or hold a load. For positive shut-off use AirTAC's PHV finger valve, and keep the PSL603B-S dedicated to speed setting. Also note no published flow, Cv or turns-from-closed figure exists for this part - capacity scales with the Dia 6 bore and is characterised by curve only.
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