Castair CLB1010 — 1" x 1" Inline Check Valve, NPT Female Inlet/Outlet
The CLB1010 is a 1-inch by 1-inch NPT female inline check valve from Castair. It is part of the Castair inline check valve series — female NPT connections on both the inlet and outlet, designed for installation in compressed air distribution lines to allow airflow in one direction only and prevent backflow.
Inline check valves like the CLB1010 are used at several points in a compressed air system: at the outlet of the compressor pump before the receiver tank to prevent tank air from backflowing into the pump on shutdown, in multi-compressor installations to prevent one unit from pressurizing another, and in distribution systems where zone isolation is needed. The 1-inch female-by-female NPT configuration threads directly into standard pipe fittings or manifolds without adapters.
What This Unit Does
- One-Way Flow Control: Allows air to pass in one direction. When upstream pressure drops below downstream pressure, the check closes automatically to prevent reverse flow.
- Female NPT Inlet and Outlet: Both ports are 1-inch NPT female — thread a nipple or male-threaded fitting into each port to install inline in your system.
- Inline Body: Straight-through flow path — simpler installation than tank-mount check valves, and interchangeable with standard pipe tee or union connections.
- Castair Construction: Built to the same standards as Castair's other major air system components. Suited for industrial and commercial compressed air service.
Castair Inline Check Valve Lineup (CLB Series)
The CLB series covers the most common pipe sizes for distribution systems:
- CLB1414 (1/4" x 1/4"): NPT Female — light-duty drops and control lines
- CLB1212 (1/2" x 1/2"): NPT Female — small shop and garage installations
- CLB3434 (3/4" x 3/4"): NPT Female — mid-size commercial systems
- CLB1010 (1" x 1"): NPT Female — main line and large commercial/industrial installations
- CLB112112 (1-1/2" x 1-1/2"): NPT Female — high-volume industrial distribution
Castair also offers in-tank check valves (CTB and CTD series) for direct tank installation with a side port for unloaders — rated at 500 PSIG, 400°F. The CLB series is for inline distribution piping, not for direct tank mounting.
When Do You Need an Inline Check Valve?
- Multi-compressor setups: When two or more compressors feed a common receiver or distribution manifold, a check valve on each compressor outlet prevents backflow from the running unit into the idle unit.
- Zone isolation: Check valves at branch points prevent back-pressurization of an idle branch from an active one when check valves replace or supplement ball valves.
- Receiver tank protection: Some installations use inline check valves between the pump and receiver as a backup to the standard tank check — particularly in high-cycle or high-vibration environments.
Technical Specifications
- Part Number: CLB1010
- Inlet Size: 1" NPT Female
- Outlet Size: 1" NPT Female
- Body Style: Inline — straight-through flow path
- Connection Type: NPT Female both ends
- Series: CLB Inline Check Valve
- Manufacturer: Castair, Spicer, Minnesota
Why Buy From Air Compressor Factory Direct?
We have sold and supported Castair air system components since 2016. We carry the complete CLB inline check valve series and the full Castair component lineup. Call 866-217-0063 if you need help selecting the right check valve type and size for your installation. Free shipping on qualifying orders, full manufacturer warranty, free technical support.
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