Airtac PSL Throttle Speed Control Fitting PSL803BD-S
SUS304 stainless variant (-S)The AirTAC Airtac PSL Throttle Speed Control Fitting PSL803BD-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 PSL803BD-S
The PSL803BD-S is a thread-in speed controller that sets how fast an actuator moves by restricting air in one direction and letting it pass freely the other way. This code carries the B suffix, so it is a meter-in controller: flow from the 3/8in PT port into the Dia 8 tube runs at full bore, and the return path through the throttling column is what gets squeezed. AirTAC's guidance is that meter-out is the first choice for a solenoid valve driving a double-acting cylinder, because throttling the exhaust builds a back-pressure cushion and keeps the stroke smooth. Meter-in is the correct pick for single-acting cylinders, where there is no exhaust side to cushion.
The -S suffix makes this the stainless build: the brass throttling column of the standard PSL is replaced with SUS304, and the spring gasket is stainless too, with the body in aluminium alloy or SUS304 depending on the part. Pressure, vacuum, temperature and dimensions are identical to the standard part. The grey body is swapped for black (the D colour code), adjustment is by a knob with an aluminium locking cap that you tighten down by hand so vibration cannot drift the setting, and the tube port points in one fixed direction.
Airtac PSL Throttle Speed Control Fitting PSL803BD-S Technical Specifications
| Model | Airtac PSL Throttle Speed Control Fitting PSL803BD-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 PSL803BD-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 PSL803BD-S Is Used
Dairy bottling line single-acting pusher
On a wash-down milk-carton indexing line, a spring-return pusher advances under metered supply and retracts on its spring. The SUS304 throttling column tolerates caustic foaming cleaners that pit brass, and the locking cap holds the stroke timing through every CIP cycle.
Plating shop jig lower
Electroplating jigs lower racks of parts into chemical baths at a set speed so no splash or air entrapment occurs. Copper-free throttling avoids copper contamination in the bath chemistry, and the black PBT body wipes clean easily.
Timber pallet nailing press
A single-acting hold-down ram must bed onto rough timber without hammering the head. Meter-in control slows the power stroke while the spring return runs free, and the Dia 8 bore has the range to tune speed for hardwood versus softwood blanks.
Is the Airtac PSL Throttle Speed Control Fitting PSL803BD-S the Right Part?
Meter-in (B) suits a single-acting cylinder - a spring-return clamp, a ram that returns by load or spring - where throttling the supply gives you a controlled power stroke. If your actuator is double-acting and driven by a solenoid valve, choose the A meter-out version of this same controller instead, because meter-in on a double-acting cylinder tends to stick-slip as the load changes. The straight-tube direction on a PSL is fixed; if you need the tube to swivel to line up with the run, that is the PSS body style.
On the Dia 8 x 3/8in rung, the real neighbours are PSL603B below and PSL103B above on the same 3/8in thread. Stepping down to Dia 6 tightens the throttle range for smaller single-acting devices like compact clamps; stepping up to Dia 10 moves more air for heavier rams and press heads. Whatever size you land on, mount the controller directly in the cylinder port rather than back at the valve - the throttled air volume stays small and the speed response is crisper.
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 PSL803BD-S FAQ
It is a stainless meter-in speed controller for Dia 8 tubing with a 3/8in PT thread. Working pressure 0-1.0 MPa (0-10 kgf/cm2), negative pressure down to -750 mmHg (10 Torr), proof pressure 1.5 MPa, and a working temperature of -20 to +70 C. The throttling column is SUS304 in place of the standard brass part, the spring gasket is stainless, and the body is black (D colour code). It uses soft nylon or polyurethane tubing.
No. The stainless part shares the same dimensions, pressure ratings and adjustment behaviour as the standard PSL803B - only the throttling column material changes to SUS304. Seal the 3/8in PT taper thread with a couple of turns of PTFE tape held back from the thread end so no tape shreds can migrate into the tube circuit, and note that a PSL body has one fixed tube orientation, so plan the tube run before you tighten it in.
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