Reference Manual

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Pulp and Paper Control Valves
Introduction
This sourcebook’s intent is to introduce a pulp
and paper mill’s processes, as well as the use of
control valves in many of the processes found in
the mill. It is intended to help you:
D Understand pulp and paper processes
D Learn where control valves are typically
located within each process
D Identify valves commonly used for specific
applications
D Identify troublesome/problem valves within
the process
The information provided will follow a standard
format of:
D Description of the process
D Functional drawing of the process
D Fisher
R
valves to be considered in each
process and their associated function
D Impacts and/or considerations for
troublesome/problem valves
Valve Selection
The information presented in this sourcebook is
intended to assist in understanding the control
valve requirements of general pulp and paper
mill’s processes.
Since every mill is different in technology and
layout, the control valve requirements and
recommendations presented by this sourcebook
should be considered as general guidelines.
Under no circumstances should this information
alone be used to select a control valve without
ensuring the proper valve construction is identified
for the application and process conditions.
All valve considerations should be reviewed by the
local business representative as part of any valve
selection or specification activity.
Control Valves
Valves described within a chapter are labeled
and numbered corresponding to the identification
used in the process flow chart for that chapter.
Their valve function is described, and a
specification section gives added information on
process conditions, names of Fisher valves that
may be considered, process impact of the valve,
and any special considerations for the process
and valve(s) of choice.
Process Drawings
The process drawings within each chapter show
major equipment items, their typical placement
within the processing system, and process flow
direction. Utilities and pumps are not shown
unless otherwise stated.
Many original equipment manufacturers (OEMs)
provide equipment to the pulp and paper
industry, each with their own processes and
proprietary information. Process drawings are
based on general equipment configurations
unless otherwise stated.
Problem Valves
Often there are references to valve-caused
problems or difficulties. The list of problems
include valve erosion from process media,
stickiness caused by excessive friction (stiction),
excessive play in valve to actuator linkages
(typically found in rotary valves) that causes
deadband, excessive valve stem packing
leakage, and valve materials that are
incompatible with the flowing medium. Any one,
or a combination of these difficulties, may affect
process quality and throughput with a resulting
negative impact on mill profitability.
Many of these problems can be avoided or
minimized through proper valve selection.
Consideration should be given to valve style and
size, actuator capabilities, analog versus digital
instrumentation, materials of construction, etc.
Although not being all-inclusive, the information
found in this sourcebook should facilitate the
valve selection process.