The AirTAC GFR300-08 AirTAC Filter Regulator PT1/4 Low-Pressure is a genuine G-series filter regulator: water separation, 40 µm particulate filtration and balanced-type pressure regulation combined in a single body. It has PT1/4" ports, a differential-pressure drain and regulates 0.15 - 0.9 MPa (20 - 130 psi). It does not lubricate — add a GL lubricator, or order the GFC two-unit set, if downstream equipment needs oil.
The AirTAC GFR300-08 is a filter regulator: it removes water and particulate from compressed air and regulates downstream pressure in a single compact body. This 300-size unit is fitted with a 1/4 in PT port, the standard 40 um filter element, and a differential-pressure drain that bleeds collected condensate automatically whenever the pressure differential across the element rises. It is the low-pressure (L) type, intended for circuits that run below standard regulator settings, and it carries an embedded square gauge scaled in psi so the set pressure is visible at a glance. The polycarbonate bowl suits the -5 to 70 C (non-freezing) operating range, with a maximum inlet pressure of 1.0 MPa (145 psi).
This is a genuine AirTAC part. The GFR family spans sizes 200, 300, 400 and 600 with port sizes from 1/8 in to 1 in, optional 5 um (W) filtration, automatic or manual drains, G or NPT thread options, and a choice of gauge scales. Because AirTAC publishes flow only as curves rather than a single rated figure, we confirm flow and datasheet figures for your application on request.
| Model | GFR300-08 AirTAC Filter Regulator PT1/4 Low-Pressure |
|---|---|
| Series | GFR300 filter regulator |
| Port size | PT1/4" (PT thread) |
| Filtering grade | 40 µm |
| Regulating range | 0.15 - 0.9 MPa (20 - 130 psi) |
| Pressure type | Low-pressure type |
| Adjusting mechanism | Balanced type |
| Fluid | Compressed air |
|---|---|
| Max. working pressure | 1.0 MPa (145 psi) |
| Temperature range | -5 to +70 °C (unfreeze) |
| Drain type | Differential-pressure drain |
| Bowl material | PC |
| Pressure gauge | Fitted — square, psi scale |
| Reflux valve | Not fitted |
Specifications follow the official AirTAC G-series air-preparation data. The regulating band is set by the drain type: automatic and differential-pressure drains regulate 0.15 - 0.9 MPa, a manual drain regulates 0.05 - 0.9 MPa. The low-pressure type adjusts over a lower band than standard; we confirm the exact figures from the factory datasheet. Air must not freeze in the unit. Flow curves, weight and outline dimensions are not published in our data set — ask us and we will confirm from the factory datasheet.
| GFR300 | G-series filter regulator, 300 body — sets the port range. |
|---|---|
| 08 | Port size PT1/4". This body offers 08 = PT1/4", 10 = PT3/8", 15 = PT1/2". |
| (blank) | Drain: Differential-pressure drain — this also sets the regulating band (0.15 - 0.9 MPa (20 - 130 psi)). |
| L | Low-pressure type. Blank is standard, L is the low-pressure type. |
| J | Supplied without bracket. |
| (blank) | Pressure gauge fitted (blank). |
| F | Gauge shape: Square. C is round, F is square. |
| 2 | Gauge scale: psi. 1 is MPa, 2 is psi, 3 is bar. |
| (blank) | Filtering grade 40 µm. Only 40 µm (blank) and 5 µm (W) exist. |
| (blank) | PT thread. PT is the default; G is BSPP and T is NPT. |
| (blank) | No reverse-flow valve (the default). |
Field order is size, port, drain, type, bracket, gauge, shape, scale, grade, thread, reflux — a blank position takes the default. Example: GFR300-08 is a 300 body, PT1/4", differential drain, standard type, bracket included, gauge fitted, 40 µm, PT thread, no reflux valve.
A larger body carries a larger port and holds set pressure better as flow rises. AirTAC publishes flow only as curves, so size the body from your peak demand with headroom. The GFR600 uses an aluminium-alloy bowl; the 200, 300 and 400 bodies use PC.
| This model | GFR300 · PT1/4" · 40 µm |
|---|---|
| One size down | GFR200 |
| One size up | GFR400 |
| Add lubrication | GFC300-08 (two-unit set) |
On a machine-tool clamping circuit that runs at reduced line pressure, the GFR300-08 filters incoming shop air to 40 um and holds a stable, low set pressure to the clamp cylinders, with the psi gauge letting the setter verify the setting.
Feeding air to conveyor-mounted sorting flaps and blow-off nozzles on a packaging line, this 1/4 in filter regulator strips water carryover from the main ring main and keeps the low working pressure the actuators were set up for.
At a lab bench running small pneumatic test rigs, the low-pressure type regulator gives fine control below standard plant pressure, while the differential-pressure drain and 40 um element keep the bench circuit clean and dry without daily bowl draining.
Size and port: the 300 frame with its 1/4 in PT port sits in the middle of the GFR range - step up to 400/600 or down to 200 if the line's air demand points elsewhere, and match the port to your existing pipework (PT is standard; G/BSPP and NPT are order options). Drain: this unit uses the differential-pressure drain, which needs no daily attention; choose automatic (A) for unattended drains or manual (M) where you want positive control. Filtration: 40 um is standard here; specify the W variant for 5 um where downstream valves or cylinders need finer protection. Gauge: the embedded square gauge is fitted in psi scale; MPa or bar scales and an external round gauge are alternatives. Note this is the low-pressure (L) type and carries no mounting bracket (J) - add a bracket if you panel-mount. Flow for this family is published as curves, not a single rating, so ask us to confirm sizing against your application before ordering.
Quick checklist
The PC bowl must not be cleaned with solvents — wipe it with a dry cloth. Without the K option, air cannot flow back through the unit. A filter regulator adds no oil to the line.
AirTAC publishes flow for the GFR series as curves, not as a single rated figure, so we do not quote a number. Tell us your application and we will confirm the flow and datasheet figures for the GFR300-08 on request before you order.
Yes. The embedded square gauge is standard on GFR units and this configuration is scaled in psi (gauge code F2). MPa (scale 1) and bar (scale 3) versions, plus an optional external round gauge, are available - just specify the scale when ordering.
Genuine AirTAC parts produced by AirTAC factory.
Covers non-human-caused product damage.
Standard models usually ship in 3-4 days.
Most inquiries answered within 7-8 hours.
Send us the quantity, thread type (PT / G / NPT), gauge scale and destination. We confirm price, availability and lead time — usually within 7-8 hours.