The AirTAC GFR300-08 AirTAC Filter Regulator 1/4 in NPT 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 GFR300-08 is an AirTAC GFR300 filter regulator: water and particulate filtration plus downstream pressure regulation in a single compact body. This configuration is built with a 1/4 in NPT port, the low-pressure regulator type for circuits that run below standard set pressures, a 40 um standard filter element, and a differential-pressure drain that bleeds collected condensate automatically as flow passes through. The embedded square pressure gauge is fitted with a bar scale, and the unit is supplied without a mounting bracket.
This is a genuine AirTAC part in the GFR300 size class, one of four sizes (200, 300, 400, 600) that step up in port and flow capacity. Across the GFR line you can order alternative ports and threads (PT standard, G or NPT), automatic or manual drains, a 5 um fine-filter element (code W), gauge scale options, and a mounting bracket. Flow is published as curves rather than a single rated figure, so ask us to confirm sizing or any datasheet figure against your application before ordering.
| Model | GFR300-08 AirTAC Filter Regulator 1/4 in NPT Low-Pressure |
|---|---|
| Series | GFR300 filter regulator |
| Port size | PT1/4" (NPT 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, 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". |
| (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. |
| 3 | Gauge scale: bar. 1 is MPa, 2 is psi, 3 is bar. |
| (blank) | Filtering grade 40 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" · 40 µm |
|---|---|
| One size down | GFR200 |
| One size up | GFR400 |
| Add lubrication | GFC300-08 (two-unit set) |
On a carton-sealing or wrapping line, actuator circuits often run at reduced set pressures. This low-pressure filter regulator cleans the supply and holds the reduced setting, with the bar-scale square gauge giving the operator a direct readout at the machine.
Finishing lines feeding spray guns need air stripped of water and pipe scale before it reaches the nozzle. Mounted at the booth drop, this unit filters the supply, regulates the gun feed pressure, and its differential-pressure drain sheds collected condensate during continuous spraying.
Clamp cylinders on a CNC cell need steady, filtered air to hold parts consistently through the cycle. This 1/4 in NPT filter regulator conditions the branch line feeding the fixtures, and the embedded square gauge lets the setter verify the clamping circuit pressure at a glance.
Start with the port step: the 300 size carries a 1/4 in port, and moving to 200, 400 or 600 changes both the connection and the flow capacity, so match the size to the air demand of the circuit rather than the pipe alone. This unit is the low-pressure type (code L), intended for systems regulated below standard set pressures; confirm the working band suits your circuit. The 40 um element suits general plant air; choose the 5 um W element where finer particulate removal matters. Drain choices are differential-pressure (fitted here), automatic (A) or manual (M). The square gauge ships with a bar scale (F3); MPa and psi scales and an external round gauge are alternatives. Thread is NPT here, with PT standard and G available to order, and the J code means no mounting bracket is included.
Flow for this series is published as curves, not a single rating, so we cannot quote one number honestly. Send us your application details and we will confirm sizing from the datasheet before you order.
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 rather than a single rated figure, so we do not quote one number on the page. Tell us your application and required flow, and we will confirm sizing against the datasheet curves for this 1/4 in, 300-size unit before you order.
The L code marks the low-pressure regulator type, intended for circuits regulated below standard set pressures; the exact adjustment range for this variant is not published in the standard listing, so we confirm it on request. The rest of the code decodes as: 1/4 in NPT port, 40 um filter, differential-pressure drain, no bracket, square gauge with bar scale, and no reverse valve.
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.