The AirTAC GFR300-08 NPT1/4 AirTAC Filter Regulator 5 um Auto Drain is a genuine G-series filter regulator: water separation, 5 µm particulate filtration and balanced-type pressure regulation combined in a single body. It has PT1/4" ports, a automatic 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 GFR300-08 is an AirTAC GFR-series filter regulator: a single body that removes water and particulate from compressed air and regulates downstream pressure. This unit is built on the 300 size with a 1/4 in NPT port, carries a 5 um filter element (the finer of the two published grades), an automatic drain that expels collected condensate without manual attention, and a fitted embedded square gauge scaled in bar. It is the low-pressure type, intended for circuits that run below standard line pressure, has a polycarbonate bowl, and is supplied without a mounting bracket.
This is a genuine AirTAC part, rated for a maximum inlet pressure of 1.0 MPa (145 psi) and an operating temperature of -5 to 70 C (non-freezing). The GFR range spans 200, 300, 400 and 600 sizes with ports from 1/8 to 1 in, and options for PT, G (BSPP) or NPT threads, manual, automatic or differential-pressure drains, 40 um or 5 um elements, and gauge scales in MPa, psi or bar. Published flow data appears as curves rather than a single rating, so ask us to confirm sizing figures from the datasheet for your application.
| Model | GFR300-08 NPT1/4 AirTAC Filter Regulator 5 um Auto Drain |
|---|---|
| Series | GFR300 filter regulator |
| Port size | PT1/4" (NPT thread) |
| Filtering grade | 5 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 | Automatic drain |
| Bowl material | PC |
| Pressure gauge | Fitted — square, bar 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". |
| A | Drain: Automatic 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. |
| 3 | Gauge scale: bar. 1 is MPa, 2 is psi, 3 is bar. |
| W | Filtering grade 5 µm. Only 40 µm (blank) and 5 µm (W) exist. |
| T | NPT 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" · 5 µm |
|---|---|
| One size down | GFR200 |
| One size up | GFR400 |
| Add lubrication | GFC300-08 (two-unit set) |
Feeding spray guns and atomising heads on a finishing line, where the low-pressure regulator holds a steady, filtered supply to the gun while the 5 um element keeps moisture and particles out of the finish.
Regulating and filtering the air to swing clamps and hold-downs on a machining or assembly fixture, with the automatic drain keeping condensate out of the clamp cylinders and the bar gauge giving operators a local pressure readout.
Air preparation for pilot-operated control valves on a packaging machine, where the 5 um grade protects the valve spools and the low-pressure regulator matches the supply to the valve stack's operating band.
The 300 size with a 1/4 in NPT port suits compact branch lines; step up to 400 or 600 where larger ports are needed. Flow is published as curves rather than a single rating, so ask us to confirm sizing against your application before ordering. The 5 um element (code W) is the finer choice over the standard 40 um where downstream valves and instruments need cleaner air. The automatic drain handles condensate removal on its own; manual and differential-pressure drains are available in the family if you prefer direct control or energy saving. Gauges are embedded square as standard, with optional external round gauges in MPa, psi or bar scales. PT is the standard thread; G (BSPP) and NPT are order options - this unit is specified in NPT. Brackets are optional, and this configuration omits one.
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 GFR flow data as curves rather than a single rated figure, so we do not quote a number here. Send us your line pressure and downstream demand and we will confirm the sizing from the datasheet on request.
The W suffix in the code selects the 5 um element, the finer of the two published grades. Choose it where downstream valves, cylinders or instruments need cleaner air; the standard 40 um element suits general workshop air. Both grades are available across the GFR range.
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.