Castair 3/8"x1/2" In-Tank Check Valve NPT Female Fitting Inlet / NPT Male Outlet CTB3812
The Castair CTB3812 is an asymmetric in-tank check valve — 3/8" NPT female inlet, 1/2" NPT male outlet. At $21.18, it's used where the compressor head discharge port is 3/8" NPT but the tank connection is 1/2" NPT, bridging these two sizes in one valve body without additional reducers. Rated to 500 PSIG and 400 degrees F with a 1/8" side port for unloader connection.
When You Need the CTB3812
- Compressor head has a 3/8" NPT male discharge port (common on smaller portable and light commercial compressor heads)
- Tank has a 1/2" NPT female bung
- Need to bridge the two sizes in one valve body without reducers or adapters
Technical Specifications
- Part Number: CTB3812
- Inlet Connection: 3/8" NPT Female
- Outlet Connection: 1/2" NPT Male
- Pressure Rating: 500 PSIG
- Temperature Rating: 400 degrees F
- Unloader Port: 1/8" side port
- Price: $21.18
- Manufacturer: Castair (Spicer, Minnesota)
Companion Compression Inlet Version
The CTD3812 (3/8" compression tube fitting inlet / 1/2" NPT outlet, $20.33) performs the same bridging function with copper tubing inlet rather than a threaded NPT connection. If your discharge runs 3/8" copper tubing from the head, use CTD3812 instead.
Full CTB Series Reference
- CTB3812 — 3/8" x 1/2" (this listing), $21.18
- CTB1212 — 1/2" x 1/2", $20.33
- CTB1234 — 1/2" x 3/4", $29.65
- CTB3434 — 3/4" x 3/4", $31.34
- CTB1010 — 1" x 1", $50.82
Why Buy From Air Compressor Factory Direct?
We stock the full Castair check valve line. If you need to confirm your compressor head thread size, call us with your compressor model and we'll verify which valve fits before it ships.
- Free shipping on qualifying orders to the lower 48
- Free tech support — fitment verification by phone
- Full manufacturer warranty on all Castair products
Call 866-217-0063 for quick answers and help!
