The AirTAC GR400-15 NPT1/2 AirTAC Low-Pressure Air Regulator is a genuine G-series air pressure regulator. It holds a stable downstream pressure over the range 0.05 - 0.4 MPa (7 - 58 psi) with PT1/2" ports, and ships with a pressure gauge. A regulator does not filter the air — put a GF filter upstream, or use a GFR filter regulator, when water and particulate must also be removed.
The GR400-15 is a genuine AirTAC GR-series air pressure regulator for compressed air only. This is the 400 size with 1/2 in NPT ports, built as the low-pressure type: it regulates downstream pressure up to 0.4 MPa, with a maximum inlet (working) pressure of 1.0 MPa (145 psi) and an operating temperature range of -20 to 70 C, the widest in the G family. The embedded square gauge (MPa scale) is fitted, a reverse/check valve is fitted to hold the set pressure, and no mounting bracket is included, though the GR body is also panel-mountable.
GR regulators are available in sizes 200, 300, 400 and 600 with port sizes from 1/8 in to 1 in, in standard or low-pressure types, with or without gauge, bracket or reverse valve, and with PT, G (BSPP) or NPT threads as order options. Flow figures are published as curves rather than a single rating, so we confirm the datasheet and sizing on request.
| Model | GR400-15 NPT1/2 AirTAC Low-Pressure Air Regulator |
|---|---|
| Series | GR400 pressure regulator |
| Port size | PT1/2" (NPT thread) |
| Regulating range | 0.05 - 0.4 MPa (7 - 58 psi) |
| Pressure type | Low-pressure type |
| Bracket | Supplied without bracket |
| Fluid | Compressed air |
|---|---|
| Max. working pressure | 1.0 MPa (145 psi) |
| Temperature range | -20 to +70 °C |
| Pressure gauge | Fitted — square, MPa scale |
| Reflux valve | Fitted (reverse flow permitted) |
| Mounting | Panel mounting; optional fixing bracket |
Specifications follow the official AirTAC G-series air-preparation data. Note the GR temperature range is -20 to +70 °C, wider than the other G-series units. A regulator has no bowl and no filter element, so there is no filtering grade. Flow curves, weight and outline dimensions are not published in our data set — ask us and we will confirm from the factory datasheet.
| GR400 | G-series pressure regulator, 400 body — sets the port range. |
|---|---|
| 15 | Port size PT1/2". This body offers 10 = PT3/8", 15 = PT1/2". |
| L | Low-pressure type — 0.05 - 0.4 MPa (7 - 58 psi). 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. |
| 1 | Gauge scale: MPa. 1 is MPa, 2 is psi, 3 is bar. |
| 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, type, bracket, gauge, gauge shape, scale, thread, reflux — a blank position takes the default. Example: GR300-08LNK is a 300 body, PT1/4", low-pressure type, no gauge, with 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 rather than from a single rated figure.
| This model | GR400 · PT1/2" · 0.05 - 0.4 MPa (7 - 58 psi) |
|---|---|
| One size down | GR300 |
| One size up | GR600 |
| Line order | Filter first, then regulator, then lubricator |
Set a steady, lower-than-line clamping pressure for workholding cylinders on a machining centre, with the fitted check valve helping hold the setting if upstream supply dips.
Feed spray guns or coating applicators that are rated for low supply pressures, keeping the regulated pressure within the 0.4 MPa ceiling this low-pressure type provides.
Regulate the air to sealing arms, pushers and diverters on a packaging line where gentle, repeatable low-pressure actuation protects product and tooling.
Start with the port step: the 400 size takes 1/2 in ports, one step up from 3/8 in and one below 3/4 in, so match the size to the air demand of the circuit rather than to the pipe alone. This unit is the low-pressure (L) type, correct where the process must never see more than 0.4 MPa; for general-duty regulation up to 0.9 MPa choose the standard GR type instead. Other decodable choices: gauge scale (MPa standard here, psi or bar available), thread (PT is the AirTAC standard, with G and NPT as order options - this unit is NPT), bracket (omitted on this code, but the GR is panel-mountable), and the K option for a reverse/check valve, which is fitted here. Flow is published as curves, not a single rating, so ask us to confirm sizing against your application before ordering.
Quick checklist
The reflux valve lets air flow back through the regulator, which is useful when downstream volume must vent quickly. A regulator does not remove water or particulate; that is the filter's job.
AirTAC publishes GR flow performance as curves, not as a single rated figure, so we do not quote a l/min, SCFM or Cv number. Tell us your application and we will confirm the flow data from the datasheet and check the sizing for you on request.
L marks the low-pressure type of regulator: the adjustment range tops out at 0.4 MPa instead of the standard GR range. Maximum inlet pressure is still 1.0 MPa (145 psi). This code also carries a square MPa gauge (F1), NPT thread (T), no bracket (J) and a reverse/check valve (K).
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.