The Castair G151816B is a 1/8-inch NPT back-mount pressure gauge with a 1.5-inch dial face, reading 0 to 160 PSI. Priced at $11.01, this is a straightforward replacement gauge for compressor tanks, regulators, and air system panels where a compact, back-mount gauge is the correct form factor.
Back-mount means the NPT fitting exits from the back of the gauge case — so the gauge mounts flush against a panel or tank wall with the dial facing out toward the operator. This is the correct configuration for panel-mounted installations and compressor tank gauge ports that are recessed or surface-mounted. If your gauge port faces toward the operator rather than being recessed in a panel, you want a bottom-mount gauge (G151816U) instead.
Key Features
- 1/8 inch NPT connection — standard small-port gauge fitting used on regulators, manifolds, and small compressor ports
- Back-mount configuration — connection exits from the rear of the gauge for panel or flush-mount installations
- 1.5-inch dial — compact size for tight panel spaces or small compressor housings
- 0-160 PSI range — appropriate for standard shop compressed air systems operating at 90-150 PSI
- Genuine Cast Air replacement component — correct specification for Cast Air compressor and regulator applications
Technical Specifications
- Part Number: G151816B
- Connection: 1/8 inch NPT
- Mount: Back mount
- Dial Size: 1.5 inch
- Range: 0-160 PSI
Back Mount vs. Bottom Mount — Which Do You Need?
Back mount (this gauge, G151816B): the port threads into the back of the gauge housing. The gauge mounts against a flat surface — panel, tank face, bracket — with only the dial visible from the front. Bottom mount (G151816U): the port exits from the bottom of the gauge. Used where the gauge stands vertically off a horizontal pipe or fitting. Look at your existing gauge or gauge port orientation before ordering — getting this wrong means the gauge does not fit the mounting position.
Applications
- Replacement gauge on Cast Air compressor tanks and receiver panels
- Regulator and manifold gauge port replacement on shop air systems
- Compressor control panel gauge replacement
- Any application requiring a 1/8 inch NPT, 0-160 PSI, back-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 help you confirm the correct gauge for your specific application. Free shipping on qualifying orders, full manufacturer warranty, and direct tech support at 866-217-0063.
Call 866-217-0063 for quick answers and help!
