Vent valve and method of operation thereof

摘要

Air braking system of vehicles usually have a piston compressor (C) and a desiccant (D) for drying the compressor output air. The desiccant is periodically regenerated by downstream air from e.g. a reservoir (R). When a compressor is brought on load, the initial charge of air may be oil laden. The invention provides delay means 21 to permit such initial charge of air to pass directly to exhaust.