The Castair G151816U is a 1/8-inch NPT bottom-mount pressure gauge with a 1.5-inch dial face, reading 0 to 160 PSI. Priced at $11.01, this is the bottom-mount companion to the G151816B back-mount gauge — same connection size, same range, same dial diameter, different port orientation.
Bottom-mount means the NPT fitting exits from the bottom of the gauge case. The gauge stands vertically upright off a horizontal pipe tee, manifold port, or fitting — the dial faces forward or upward, readable without craning around a panel. This is the correct configuration for most compressor tank gauges that thread directly into a horizontal port in the tank shell or a horizontal manifold fitting.
Key Features
- 1/8 inch NPT connection — standard small-port gauge fitting for regulators, manifolds, and compressor ports
- Bottom-mount configuration — port exits from the base of the gauge for vertical installation off horizontal fittings
- 1.5-inch dial — compact size appropriate for tight mounting locations
- 0-160 PSI range — covers standard shop compressed air operating pressures of 90-150 PSI
- Genuine Cast Air replacement component — correct specification for Cast Air compressor applications
Technical Specifications
- Part Number: G151816U
- Connection: 1/8 inch NPT
- Mount: Bottom mount
- Dial Size: 1.5 inch
- Range: 0-160 PSI
Bottom Mount vs. Back Mount — Choosing Correctly
Bottom mount (this gauge, G151816U): the connection enters from directly beneath the gauge body. The gauge sits upright on top of the fitting. Use this when the gauge port is horizontal and the gauge needs to stand vertical with the dial facing you. Back mount (G151816B): connection enters from behind the gauge case. Use this for panel-mounted installations where the gauge is recessed into a surface. Check your port orientation before ordering — this is one of the most common gauge ordering errors.
Applications
- Replacement gauge on Cast Air compressor tank ports and receiver fittings
- Air regulator and manifold gauge replacement
- Inline compressed air system pressure monitoring
- Any application requiring a 1/8 inch NPT, 0-160 PSI, bottom-mount gauge
Why Buy From OEM Diagnostic Tools?
We have been supplying compressed air components since 2016. We stock genuine Cast Air gauges and can confirm the correct mount type and range for your application before you order. Free shipping, full warranty, tech support at 866-217-0063.
Call 866-217-0063 for quick answers and help!
