Profile: H L R Controls, Inc. is a manufacturer of pneumatic and hydraulic instruments. Our product line includes velocity check & hydraulic interface valves, auto & manual reset relays, and sand probes. Our manual reset relays are designed typically for three way "block & bleed" control circuit applications. They are frequently used as "group master" or "two phase" flow control valves. Our relays generally use pilot supply pressures of 30-125 PSI for their operation. Our pressure sensors are flow control devices that shift the internal flow path within the assembly, as it responds to a pre-determined change in monitored pressure. They can be used in either three (3) way, block and bleed applications, or in two (2) way bleed service.