Evacuating the Manifold Gauge Set

Evacuating the Manifold Gauge Set

Attach the center (service) hose to a vacuum pump and start the pump. Open fully both high and low valves and allow the vacuum to remove air and moisture from the manifold set for at least five minutes.

CAUTION: It is imperative that the vacuum pump is not subjected to a positive pressure of any degree. Therefore the pump must be fitted with an isolation valve at the center (service hose) connection and this valve must be closed before the pump is switched off. This operation replaces the 'purge' procedure used on previous systems. Observe the manufacturer's recommendation with regard to vacuum pump oil changes.

Turn the vacuum pump off and isolate it from the center service hose but do not open the hose to atmosphere.