STEM-TYPE VALVE OPERATION
This manually operated service valve has adjustable stem, located under a protective cap. Valve stem must be manually positioned when making gauge connections and/or reading system pressure on the gauges. (Схема №2)
SCHRADER-TYPE VALVE OPERATION
Schrader valve is similar in construction and operation to a tire valve. When a test gauge hose (which has a valve core depressor) is attached, Schrader stem is pushed inward to the open position and allows system pressure to reach the gauge.
If test hose being used does not have a built-in core depressor, an adapter must be used. Never attach hoses or adapters to a Schrader valve unless it is first connected to manifold gauge set.
Note. Although similar in construction and operation to a tire valve, the Schrader-type valve cannot be replaced with a tire valve.