It works like a tire valve, letting gauges and recovery or charging hoses connect without shutting the system down. The cores restrict flow, so techs pull them with a core removal tool to evacuate and recover faster. Cores leak if damaged or overtightened, which is why the brass caps with O-ring seals must always go back on.
Pull the Schrader cores before you start the vacuum, you'll get down twice as fast through the core tools.
Also heard as
- Schrader
- Schrader core
- valve core
Related terms
Service valve
A manually operated valve on a condensing unit or receiver that isolates refrigerant and provides a gauge port.
Pull a vacuum
To evacuate a refrigeration system with a vacuum pump, removing air and moisture before charging.
Gauges
The manifold gauge set techs connect to service ports to read system pressures, saturation temperatures and charge.
Recovery
Removing refrigerant from a system into a recovery cylinder instead of venting it to the atmosphere.