decompression valve for lubrication circuit - has ball with biased sleeve maintaining pressure in circuit when lubrication pump is not operating

摘要

The reciprocating lubrication pump delivers oil through the non-return valve (17) to the pressure retaining valve (1). When the pump is operating oil passes through the bore (14), lifting the ball (8) off its seat (5) and passing through the bore (4) to the outlet (13). When the pump ceases operating the ball (8) falls back on to its seat and prevents any return flow of the oil. At the same time the spring (22) presses the inner sleeve (7) upwards to close the upper valve (15) and maintain the pressure in the lubrication circuit.