Automatic Air Vent | 9390N Series | MNPT Brass Body | 150 PSI CWP | Compact Design
Automatic Air Vent | 9390N Series | MNPT Brass Body | 150 PSI CWP | Compact Design
9390N Series Automatic Air Vents efficiently eliminate trapped air from hydronic heating and cooling systems, improving flow, reducing noise, and extending equipment life. Designed with a durable ASTM B283 C37700 brass body and corrosion-resistant internals, this compact air vent provides long-term reliability in both residential and commercial closed-loop systems.
The 9390N operates automatically without manual intervention—making it ideal for air elimination in boilers, radiant floor loops, and fan coil units. Its MNPT threaded connection ensures easy installation and leak-free operation under continuous system pressure.
Key Features & Benefits
- Durable Brass Construction — Solid ASTM B283 C37700 brass body and vent provide corrosion resistance for long service life.
- Automatic Maintenance-Free Venting — Continuously releases air from hydronic systems to prevent airlock, pump damage, and performance loss.
- Wide Temperature Range — Operates from 32°F to 230°F; for service above 212°F, use with anti-boil additives only.
- Compact Lightweight Design — Low-profile body (under 3″ height) and 0.34 lb weight allow easy installation in tight mechanical spaces.
- Multiple MNPT Sizes — Available in ¼″, ⅜″, and ½″ NPT for maximum compatibility with standard hydronic systems.
Pressure & Temperature Ratings
| Pressure Rating | Temperature Range | Media |
|---|---|---|
| 150 PSI CWP | 32 °F – 230 °F | Water (anti-boil fluids above 212 °F) |
Dimensions & Weight
| Size | Thread (N) | A [in] | D [in] | H [in] | Weight [lb] |
|---|---|---|---|---|---|
| ¼″ | ¼″ - 18 NPT | 1.82 | 0.47 | 2.83 | 0.34 |
| ⅜″ | ⅜″ - 18 NPT | 1.82 | 0.47 | 2.83 | 0.34 |
| ½″ | ½″ - 14 NPT | 1.82 | 0.61 | 2.97 | 0.34 |
Material Construction
| # | Component | Material | Specification |
|---|---|---|---|
| 1 | Body | Brass | ASTM B283 C37700 |
| 2 | Float | Polypropylene1 | — |
| 3 | Cursor | Plastic | — |
| 4 | Spring | Stainless Steel | AISI 304 |
| 5 | Shutter | Plastic | — |
| 6 | Shutter Gasket | EPDM Perox | — |
| 7 | Vent | Brass | ASTM B283 C37700 |
| 8 | Cursor Mount | Stainless Steel | — |
| 9 | O-Ring | EPDM Perox | — |
| 10 | Tap | Brass | ASTM B283 C37700 |
| 11 | Vent Cap | Polypropylene1 | — |
¹ Polypropylene components used for high-temperature applications.
Applications: Hydronic heating loops, radiant floors, fan coil units, boilers, and solar thermal systems.