Hydraulic pressure relief valve

摘要

Hydraulic pressure relief valve, esp for use in mines and tunnels for hydraulic roof support systems, protects the support against excess due to rock bursts or bumps. The valve (1) is shown open on the right and closed on the left. Its casing (2) consists of an upper part (3) and the connector (5). The valve piston (10) is designed as a tubular sleeve (20) with a large relief opening and an extension of smaller dia, acting as a control piston (60). Two spacers (46,47) within and above the valve piston (10) are sepd by seal rings (19.51), made of PTFE, e.g. TEFLON TRM/600(RTM). The O-ring(75) is made of the same material.