Emerson Fisher DFA Instruction Manual

Instruction Manual
D103643X012
Fisherr DFA Variable Geometry Desuperheater
Contents
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Scope of Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Educational Services . . . . . . . . . . . . . . . . . . . . . . . . .
Principle of Operation . . . . . . . . . . . . . . . . . . . . . . . . .
Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Nozzle Maintenance and Replacement
DFA Desuperheater Variable Geometry Nozzles
DFA Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DFA Parts Ordering . . . . . . . . . . . . . . . . . . . . . . . . . . .
Parts List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Introduction

Scope of Manual

This instruction manual includes installation, maintenance, and operation information for the DFA variable orifice
desuperheater. Refer to separate instruction manuals for information on the actuator and accessories.
Do not install, operate, or maintain a DFA desuperheater without being fully trained and qualified in valve, actuator,
and accessory installation, operation, and maintenance. To avoid personal injury or property damage, it is important
to carefully read, understand, and follow all the contents of this manual, including all safety cautions and warnings. If
you have any questions about these instructions, contact your Emerson Process Management sales office before
proceeding.

Description

The Fisher DFA desuperheater flexible architecture (figure 1) incorporates both a water control element and a
variable­geometry mechanically atomized, self­contained desuperheater for moderate to high flow variation. It is
installed through a flanged connection on the side of an NPS 8 or larger pipeline.
The desuperheater design incorporates an integral thermal liner inside the desuperheater body pipe. This minimizes
the potential for thermal shock when cool water is introduced to the unit which has been heated to the operating
steam temperature.
The nozzle mount for the DFA is engineered to minimize the potential for excitation due to vortex shedding and flow
induced vibration. The DFA desuperheater is installed through a flanged connection on a DN 200 (NPS 8) or larger
pipeline. Maximum unit C
www.Fisher.com
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is 15.0.
V
Figure 1. Fisher DFA Variable Geometry
Desuperheater
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DFA Desuperheater
August 2013