Series 6600 On-Off & Semi-Modulating
Automatic Recirculation Valve

The demands of modern industrial processes has led to the need for higher and higher pressure. This in turn has created a need for centrifugal pumps with high heads and low specific speeds. Tolerances within such pumps have become smaller and this has led to the pumps being more sensitive to temperature increases. It is therefore essential that the flow through such pumps should not fall below minimum cooling quantities. The design of the flow control system for centrifugal pumps therefore demands certain essential functions.

1. Protection against pump over heating due to minimum cooling flow not being maintained.
2. The ability to rapidly build pressure to achieve hydraulic balance on start up.
3. Protection against flow reversal from the feed line on pump shut down.

The conventional flow control system used to be complex and troublesome, relying and multiple interlinked valves and pressure switches. The Blackhall Automatic Recirculation Valve was designed specifically to simplify the flow control system. Since 1965 Blackhall Valves have proven themselves to be not only reliable but also extremely flexible, being utilised in areas ranging from Power Generation to Petro Chemical installations.