The AirTAC GFR300-08 AirTAC Filter Regulator NPT1/4 Low-Pressure 5um 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 manual drain and regulates 0.05 - 0.9 MPa (7 - 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 body. This 300-size unit is built with a 1/4 in NPT port, a 5 um filter element (code W) for finer filtration than the standard 40 um grade, and a manual drain you operate by hand to empty the polycarbonate bowl. It is the low-pressure type, so it is intended for circuits that run below the standard regulator band, and it carries an embedded square gauge scaled in bar so the set pressure is visible at the unit. A reverse/check valve is fitted, holding downstream pressure if the supply side is vented, and this configuration ships without a mounting bracket.
This is a genuine AirTAC part from the GFR series, which spans sizes 200, 300, 400 and 600 with port sizes from 1/8 in to 1 in, and options for drain type, filter grade, gauge scale, thread (PT standard, G and NPT to order) and bracket. Flow is published as curves rather than a single rated figure, so ask us and we will confirm the datasheet figures for your application before you order.
| Model | GFR300-08 AirTAC Filter Regulator NPT1/4 Low-Pressure 5um |
|---|---|
| Series | GFR300 filter regulator |
| Port size | PT1/4" (NPT thread) |
| Filtering grade | 5 µm |
| Regulating range | 0.05 - 0.9 MPa (7 - 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 | Manual drain |
| Bowl material | PC |
| Pressure gauge | Fitted — square, bar scale |
| Reflux valve | Fitted (reverse flow permitted) |
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". |
| M | Drain: Manual drain — this also sets the regulating band (0.05 - 0.9 MPa (7 - 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. |
| K | Reverse-flow (reflux) valve fitted. |
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) |
A workholding fixture that must clamp gently, such as a fixture pressing rubber gaskets or delicate machined parts, needs air held well below the standard regulator band. The low-pressure GFR300-08 filters the shop air to 5 um before it reaches the clamp cylinders and lets the operator read the set pressure in bar on the square gauge, while the check valve holds the clamp if the supply drops.
Bench-top test rigs and analytical instruments fed from a shop compressor need clean, steady, low-pressure air. The 5 um element strips water and fine particulate before it reaches sensitive pneumatics, the manual drain lets the technician empty the bowl at the start of each shift, and the bar-scaled gauge keeps the set point visible during a run.
Air jets and soft ejectors that nudge cartons or blister packs along a packaging conveyor work at low pressure and foul quickly on dirty air. This filter regulator conditions the 1/4 in drop to the station, the low-pressure type suits the gentle blow-off setting, and the fitted check valve keeps the jets from surging when an upstream valve vents the manifold.
Size and port set the capacity: the 300 frame with a 1/4 in NPT port suits compact machine circuits; step up to 400 or 600 where the line demands more air. The 5 um element (W) is the right choice when downstream valves or instruments want finer air than the standard 40 um grade. Choose the drain to match access: this unit has a manual drain, best where someone is at the machine regularly; automatic and differential-pressure drains suit unattended installations. The fitted square gauge reads in bar; MPa and psi scales and an external round gauge are alternatives. Thread is NPT here, with PT standard and G available to order, and a bracket can be added if this one is omitted.
One honest note before you commit: AirTAC publishes flow as curves, not a single rated number, and the regulation band for this low-pressure type is not stated as a single figure either. Send us your line pressure, set pressure and air demand, and we will confirm sizing against the datasheet before you order.
Quick checklist
The PC bowl must not be cleaned with solvents — wipe it with a dry cloth. The reflux valve permits reverse flow 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 number, so we will not quote you a figure that is not in the datasheet. Send us your line pressure, required set pressure and air consumption, and we will confirm the flow from the datasheet and check the sizing of this 300-size, 1/4 in NPT unit against your application before you order.
The M in the code gives this unit a manual drain: you open it by hand to empty collected water, which suits stations that are attended regularly; automatic and differential-pressure drains are available in the same series for unattended installations. The K adds a reverse/check valve that holds downstream pressure if the supply side is vented. Both choices are decodable from the model code, and the bracket is omitted on this configuration (code J) but can be ordered.
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.