The AirTAC GFR300-08 AirTAC Filter Regulator NPT1/4, 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 AirTAC GFR300-08 is a size-300 filter regulator that removes water and particulate from compressed air and regulates downstream pressure in a single body. This configuration is ordered with NPT1/4 ports, an automatic drain that expels collected condensate without manual attention, and a fine 5 um filter element for cleaner air than the standard 40 um grade. No gauge is fitted, so a separate gauge or a gauge-equipped variant is needed to read the outlet setting. Maximum inlet pressure is 1.0 MPa (145 psi) and the standard regulator adjusts from 0.15 to 0.9 MPa (20-130 psi). Operating temperature is -5 to 70 C, non-freezing.
This is a genuine AirTAC part. The GFR series is offered in sizes 200, 300, 400 and 600 with a choice of PT, G or NPT threads, differential-pressure, automatic or manual drains, 40 um or 5 um filtration, and gauge or no-gauge builds. Flow is published as curves rather than a single rating, so ask us to confirm sizing and datasheet figures for your application before ordering.
| Model | GFR300-08 AirTAC Filter Regulator NPT1/4, 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 | Standard 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 | Not fitted |
| 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. Standard type, regulating 0.15 - 0.9 MPa (20 - 130 psi). 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)). |
| (blank) | Standard type. Blank is standard, L is the low-pressure type. |
| (blank) | Mounting bracket included. |
| N | No pressure gauge (N). |
| (blank) | Gauge shape: Factory standard. C is round, F is square. |
| (blank) | Gauge scale: Factory standard. 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) |
Feeds clean, regulated air to the tool-clamp and chip-clearing circuits of a CNC machining centre, where the 5 um element protects precision valves from fine particulate and the automatic drain keeps condensate off the spindle-area pneumatics.
Sits upstream of the solenoid valve bank on a carton-forming packaging line, holding a steady outlet pressure for consistent sealing-cylinder action while the auto drain handles moisture from a long compressed-air run.
Provides filtered, adjustable low-pressure air to a bench-top leak and pressure-decay test rig, where the fine 5 um grade keeps sensitive test instruments clean and the outlet setting is read on a separate mounted gauge.
Choose the size and port step against the air demand of the circuit: this unit is size 300 with 1/4 in NPT ports, and larger sizes carry larger ports and more flow. For drain behaviour, automatic drain (this model) suits unattended installations, manual drain suits periodically checked points, and the default differential-pressure drain purges on pressure drop. The 5 um element here is the finer option where downstream equipment needs cleaner air than the standard 40 um grade. This build has no gauge; add one if the outlet pressure must be read at the unit. PT is the standard thread, with G and NPT as order options, and a mounting bracket is included. Flow 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 rated flow, Cv or SCFM number. Tell us your application and required flow, and we will confirm the correct size against the datasheet curves on request before you order.
The N in the code means no gauge is fitted, so the regulator is set with a separate gauge or by the downstream equipment. If you want the pressure readable at the unit, order a GFR300 variant with a gauge (square embedded or external round, in MPa, psi or bar scale) and we can confirm the options on request.
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.