The Castair C218T50U is a commercial air compressor unit in the C2 pump family, configured with a 50-gallon tank. Based on the SKU structure, this unit likely features a 2HP or similar motor, a T-frame motor configuration, 50-gallon tank, and an unloader valve (U suffix). Manufacturer product page data was not available at time of writing — contact us for complete specifications including HP, CFM output, voltage, and dimensions.
The unloader valve (U designation) is a meaningful feature: it relieves head pressure when the compressor reaches cutout, allowing the motor to restart under no-load conditions. Without an unloader, a single-phase motor has to restart against residual head pressure in the cylinder — that's a harder start, more current draw, and more motor stress. With an unloader, the motor restarts freely and the valve closes once the compressor is running. This extends motor life and reduces nuisance tripping on undersized electrical circuits.
Key Features
- Cast Air C2 Series Pump: Cast iron reciprocating pump in the C2 family for commercial duty service
- 50-Gallon Tank: Adequate air storage reserve for intermittent to moderate demand applications
- Unloader Valve (U): Head pressure unloader allows easy motor restart — extends motor life and reduces starting current demand
- Commercial-Grade Construction: Cast Air quality throughout for shop and light industrial use
- Complete Compressor Unit: Pump, motor, tank, and controls assembled — connect power and an air line to operate
Technical Specifications
- Part Number: C218T50U
- Pump Family: C2 series
- Tank Capacity: 50 gallons
- Special Feature: Unloader valve
- Manufacturer: Cast Air
- HP, CFM, max PSI, voltage, tank orientation, dimensions, weight — contact us for complete specifications and pricing. Manufacturer data was not available at time of writing.
Why the Unloader Valve Matters
On a compressor without an unloader, when the pressure switch cuts the motor out, there's still compressed air trapped above the piston. When the pressure switch calls for the motor to restart, it has to push against that trapped pressure. On single-phase motors especially, this is a hard start — higher starting current, more heat, more wear over time. The unloader valve bleeds off that trapped pressure when the compressor stops, so the next start is against atmospheric pressure. It's a small component that has a real impact on motor longevity and starting reliability, especially on circuits where the breaker or wire is sized tight.
Applications
- Shop air supply for auto service bays and tire operations
- Light commercial applications with moderate air demand
- Facilities where electrical circuit capacity is a consideration
- Applications where motor restart reliability is important
Why Buy From OEM Diagnostic Tools?
Cast Air compressors and components for commercial shops and industrial facilities — specialist supplier since 2016. Free shipping on qualifying orders. We can pull complete specifications for the C218T50U before you order — call us.
Call 866-217-0063 for pricing, availability, and complete specifications!
