Blackhall
Engineering
Series 6000
Automatic Recirculation Valve
Please
contact
Anderson-Brooksbank USA,
LLC
for a full Brochure and Data Manual
The Blackhall range of Automatic
Recirculation Valves have been designed to give absolute reliability with
maintenance requirements minimized. Each Blackhall valve is designed specifically
to suite the individual customers' requirements. The range includes both
ON/OFF and Modulating options with options available in Angle or Straightway
pattern design. The Angle patterns valve has the additional feature of
not requiring removal from the pipeline during maintenance 'Shut downs.'
By-Pass Configuration ON/OFF
The Blackhall ON/OFF Automatic
Recirculation valve is really a system which incorporates five functions
in one:
(1) Non-Return Valve:
preventing reverse flow through the centrifugal pump via the main line.
(2) By-Pass Control Valve: protecting the pump overheating by regulating
a passage of fluid through the pump during START UP, SHUT DOWN and when
the pump is run against a closed outlet.
(3) Flow Sensing
Capability: which actuates the bypass control valve.
(4) Pressure Reduction Nozzles: which dissipate the pressure energy
and allows the line fluid to be delivered to the by-pass system quietly
and safely.
(5) Non-Return Valve: preventing reverse flow through the centrifugal
pump via the the by pass line.
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Introduction
to the
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 overheating 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.

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