Reference Manual

ManualsBrandsEmerson ManualsControl ValvesEmerson Fisher Control-Disk

PULP & PAPER

Kruger, Inc. Newsprint Mill Uses Fisher

Control-Disk

™

Valves

to Reduce Variability, Maintenance, and Downtime

RESULTS

• Reduced maintenance costs by about $3,000 per valve.

• Reduced excessive ow variability by a factor of three,

improving stability and level measurement.

• Prevented “missed samples” from the PQM Analyzer.

“Installing the Control-Disk

valves was easy and did not

require any piping modifications.

The characteristic and flow

performance of this butterfly valve

is similar to that of a segmented-

ball. With this new Fisher product,

we avoided maintenance-costs

of about $3000 per valve and

reduced flow variability by a

factor of three.”

Pierre Gauthier, Instrumentation Supervisor

Kruger Inc.

APPLICATION

Level, flow, and pressure control in the refiner pulp tank.

CUSTOMER

Kruger, Inc. and its newsprint mill in Trois-Rivieres, Quebec.

CHALLENGE

Pierre Gauthier, Instrumentation Supervisor at the Kruger newsprint

mill in Trois-Rivieres, Quebec, had three knife gate valves installed to

provide level control for the refiner pulp tank. Challenge #1 was to

keep the level at the set point without major pressure variability to the

storage tank. Challenge #2 was to keep the poorly-designed valves

operating without continual and costly maintenance. The knife-gate

valves provided a variety of maintenance problems, from excessive

flow variability to leakage of the seal around the gates.

The excessive flow variability and resulting pressure fluctuations

caused instability in the sampling of the pulp to the PQM analyzer. The

PQM analyzer measures the values of fiber length and freeness of the

paper sheet. (Freeness is the porosity or space left between the pulp

fibers after being sprayed from the headbox onto the wire of the paper

machine.) Sampling is important because it directly affects porosity,

tensile strength, and other factors relating to end-product quality.

The analyzer sample is time-based, and pressure variations often lead

to “bad” samples or no samples at all. Pierre said, “The problems

multiple as the valves age and demand for TMP pulp increases. When

we close the loop, we may loose the measurement and/or have less

time to stop the lines.”

Installed 15-feet above the ground, two Control-Disk™

buttery valves (like the one above) replaced leaking knife-

gate valves at a newsprint mill in Quebec.

Summary of content (2 pages)

PAGE 1
PULP & PAPER Kruger, Inc. Newsprint Mill Uses Fisher® Control-Disk™ Valves to Reduce Variability, Maintenance, and Downtime RESULTS • Reduced maintenance costs by about $3,000 per valve. • Reduced excessive flow variability by a factor of three, improving stability and level measurement. • Prevented “missed samples” from the PQM Analyzer. APPLICATION Level, flow, and pressure control in the refiner pulp tank.
PAGE 2
PULP & PAPER SOLUTION Fortunately for Kruger, engineers within the Fisher division of Emerson Process Management had been studying the common flaws of traditional butterfly valves and developing a new, far more reliable design. Introduced this summer, the new Control-Disk™ valve delivers better adherence to set point and excellent throttling performance.