Reference Manual
METALS & MINING
Control-Disk
™
Butterfly Valves Enable Throttling Control
In Rolled-Steel Cooling System
RESULTS
• Avoided piping changes that would have cost $10K per
valve or $90K
• Reduced water usage by up to 50%
• Reduced the amount of blanched or wasted steel
APPLICATION
Water pressure and ow control
CUSTOMER
Severstal North America in Dearborn, Michigan
CHALLENGE
Severstal North America operates a fully-integrated steel mill in
Dearborn, Michigan that produces more than 3.6 million tons per
year (2007) of hot-rolled sheet. Initially, the mill had on/off buttery
valves (Jamesbury Series 830) controlling the water pressure in the
Roll Coolant system. Nine valves, installed along an 8-inch pipeline,
controlled the ow of water through pumps and spray nozzles to cool
the molten steel during the rolling process. A typical roll is 80-inches
wide and 3/16th-inches thick. Until recently, the sheet of steel was
consistently the same thickness, which meant that adjusting process
pressure was not required. In early 2009, however, the mill began
producing sheets of steel in multiple thicknesses. This requires more
precise control and varying coolant-water pressures.
With these new application requirements, the 830 Series valves
with quick-opening characteristics had some performance issues.
For one thing, they would not throttle. For another, they had no
monitoring capabilities and could not control the ow of water based
on temperature. Mill managers began to look for replacement valves
with equal percentage or even linear characteristics that would provide
better control and monitoring.
SOLUTION
Team Emerson, including engineers from Cornerstone Controls and
the Fisher division’s Rotary Design group, met with mill managers to
discuss the application requirements. Initially, the customer requested
a Design V150, but that ball-valve assembly would have required
signicant piping changes, costing up to $10K per valve. Instead, Team
Up to nine Control-Disk valves,
like the one in the foreground, will
be installed along this hallway,
controlling the flow of water to
pumps and spray nozzles.