The AirTAC GFR400-15 NPT AirTAC Filter Regulator, 1/2 in, Low-Pressure 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 PT1/2" 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 GFR400-15 is a filter regulator: it removes water and particulate from compressed air and regulates downstream pressure in a single body, so one 1/2 in NPT unit does both jobs in the air-preparation drop. This configuration is the low-pressure type (code L) for circuits that run below standard line pressure, carries the 5 um filter element (code W) for finer filtration than the standard 40 um grade, and is fitted with the embedded square gauge scaled in psi (code F2) plus a reverse/check valve (code K) to hold downstream pressure if the supply drops. The polycarbonate bowl uses differential-pressure drainage, and the mounting bracket is included.
This is a genuine AirTAC part from the GFR400 series, one of four sizes (200/300/400/600) spanning port sizes from 1/8 in to 1 in with PT, G or NPT threads, and drain, filter-grade, gauge-scale and check-valve options. Flow is published as curves rather than a single rated figure, so ask us to confirm the datasheet and sizing for your application before ordering.
| Model | GFR400-15 NPT AirTAC Filter Regulator, 1/2 in, Low-Pressure |
|---|---|
| Series | GFR400 filter regulator |
| Port size | PT1/2" (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 | Differential-pressure drain |
| Bowl material | PC |
| Pressure gauge | Fitted — square, psi 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.
| GFR400 | G-series filter regulator, 400 body — sets the port range. |
|---|---|
| 15 | Port size PT1/2". This body offers 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. |
| (blank) | Mounting bracket included. |
| (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. |
| 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 | GFR400 · PT1/2" · 5 µm |
|---|---|
| One size down | GFR300 |
| One size up | GFR600 |
| Add lubrication | GFC400-15 (two-unit set) |
Point-of-use preparation on packaging lines running below standard pressure: the 5 um element protects sealing and clamping valves while the low-pressure regulator holds the reduced setting the machine was set up for.
Conditioning the air feed to pneumatic test benches and laboratory rigs, where the 5 um grade keeps fine control valves clean and the psi-scaled square gauge gives a direct read of the regulated set point.
Supplying positioners, actuators and instrument air inside a process skid: the check valve holds the regulated pressure through brief supply dips, and the 1/2 in NPT port suits the panel's main drop.
Step up or down through the 200/300/400/600 sizes against the port and flow your line needs; this 400 size lands on a 1/2 in NPT port. Choose the drain to suit access: differential-pressure (as fitted here) dumps condensate automatically as the pressure differential builds, automatic (A) drains on a cycle, and manual (M) needs someone at the bowl. Pick 40 um for general protection or 5 um (W, as here) for finer filtration ahead of valves and instruments; note the low-pressure type (L) is the right choice when your circuit runs below standard line pressure, and its regulation range is confirmed on the datasheet on request. Gauge scale is MPa, psi or bar, and PT is the standard thread with G and NPT as order options - this unit is ordered with NPT. 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. The reflux valve permits reverse flow through the unit. A filter regulator adds no oil to the line.
AirTAC publishes flow for the GFR400 series as curves, not as a single rated number, so we do not quote a figure. Tell us your application and we will confirm the flow from the datasheet and check the sizing before you order.
The L code makes this a low-pressure regulator for circuits running below standard line pressure; its regulation range is not published in the standard table, so we confirm it on request. Drainage is differential-pressure: condensate is discharged automatically as the pressure differential builds, with no manual draining needed.
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.