Airtac PSS Exhaust Throttle Type Universal Speed Control Valve PSS1204A-S
SUS304 stainless variant (-S)The AirTAC Airtac PSS Exhaust Throttle Type Universal Speed Control Valve PSS1204A-S is a genuine universal speed controller with knob with aluminium-alloy locking cap and 360 degree adjustable tube direction, used to set the speed of a pneumatic cylinder by throttling its air.
- TypeUniversal speed controller
- SeriesPSS
- 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 PSS Exhaust Throttle Type Universal Speed Control Valve PSS1204A-S
The PSS1204A-S is AirTAC's largest universal speed controller in the stainless range. It throttles air flowing from the 1/2in PT thread port out to the Dia 12 tube and lets the return flow pass unthrottled, because this code carries the A suffix for meter-out control with a handle marked A. In practice that is the default choice: on a solenoid-valve circuit driving a double-acting cylinder, meter-out throttling leaves a back-pressure cushion ahead of the piston, so the stroke stays smooth instead of sticking and slipping as the load changes.
The -S suffix swaps the brass throttling column for SUS304 stainless steel, with the throttling body in aluminium alloy or SUS304 and a stainless spring gasket, which is why this part is specified where copper contamination or wash-down corrosion would destroy a standard fitting. Adjustment is a knob under an aluminium locking cap so the setting survives vibration, and unlike the fixed-tube PSL shape the tube port swivels a full 360 degrees, so a heavy Dia 12 line can be routed without twisting the seal.
Airtac PSS Exhaust Throttle Type Universal Speed Control Valve PSS1204A-S Technical Specifications
| Model | Airtac PSS Exhaust Throttle Type Universal Speed Control Valve PSS1204A-S |
|---|---|
| Type | Universal speed controller |
| Series | PSS |
| Adjustment | Knob with aluminium-alloy locking cap |
| Orientation | 360 degree adjustable 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 PSS Exhaust Throttle Type Universal Speed Control Valve PSS1204A-S
| PSS | Universal speed controller. |
|---|---|
| 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 PSS Exhaust Throttle Type Universal Speed Control Valve PSS1204A-S Is Used
Beverage capping head descent
On a rotary filler's rinse station, a Dia 12 cylinder lowers the capping head onto each bottle. Meter-out control plus the SUS304 column handles daily caustic wash-down without brass leaching into the product zone.
Pallet stretch-wrap ring drive
The vertical carriage of a stretch-wrapper must rise at a repeatable pace or the film overlap varies. The 1/2in port matches the large-bore lift cylinder, and the 360-degree swivel absorbs ring rotation in the tubing.
Plating line transfer gate
A copper-free actuator circuit on an electroplating conveyor indexes the transfer gate between tanks. Meter-out throttling damps the gate into its detent so racks do not splash, and no brass contacts the mist-laden air.
Is the Airtac PSS Exhaust Throttle Type Universal Speed Control Valve PSS1204A-S the Right Part?
This SKU sits at the top of the PSS ladder: on a 1/2in thread, Dia 12 is the only tube size AirTAC makes, so there is no larger step in this family. If your actuator is smaller, the neighbour down is PSS1003A-S, which pairs a Dia 10 tube with a 3/8in thread and suits more compact cylinders. If you would rather keep the 1/2in port but step the tube down, the fixed-body PSL range offers Dia 8, Dia 10 and Dia 12 on the same thread, at the cost of losing the swivel.
Mount the controller directly in the cylinder port, not back at the valve. Throttling at the cylinder keeps the cushioned air volume small and the speed response crisp, which matters more as the tube bore grows. Meter-out suits double-acting cylinders; for a single-acting spring-return actuator, choose the B suffix instead.
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 PSS Exhaust Throttle Type Universal Speed Control Valve PSS1204A-S FAQ
It is a Dia 12 tube, 1/2in PT thread, meter-out (A) universal speed controller with a 360-degree swivelling tube port. Working pressure is 0-1.0 MPa (0-10 kgf/cm2), it tolerates vacuum down to -750 mmHg (10 Torr), proof pressure is 1.5 MPa, and the operating temperature range is -20 to +70 C. It is rated for soft nylon or polyurethane tubing, and the -S suffix means a SUS304 stainless throttling column in place of brass. The stainless build carries exactly these same ratings as the standard version.
No. AirTAC publishes no separate rating for the stainless line, so the PSS1204A-S uses the same 0-1.0 MPa working pressure, 1.5 MPa proof pressure and -20 to +70 C range as the brass-column PSS1204A, and the dimension tables match. What changes is the material: the throttling column becomes SUS304 and the spring gasket becomes stainless. Note that no surface-finish figure, passivation spec or food/medical certification is published for these parts, so do not select it on the basis of one.
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