Instruction Manual Form 5251 February 1996
Designs EHAD, EHAS, & EHAT
Design EHAD, EHAS, & EHAT Valves Contents Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1 Scope of Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Installation
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Maintenance
.............................. 4 Packing Lubrication . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Packing Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . 5 Replacing Packing . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Trim Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Valve Plug Maintenance . . . . . . . . . . . . . . . . . . . . . . 8 Lapping Seats . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Trim Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Retrofit: Installing C-seal Trim . . . . . . . . . . . . . . . 14 Replacement of Installed C-seal Trim . . . . . . . . . 16 Trim Removal (C-seal Constructions) . . . . . . . . 16 Lapping Metal Seats (C-seal Constructions) . . 17 Remachining Metal Seats (C-seal Constructions) . . . . . . . . . . . . . . . . . . 17 Trim Replacement (C-seal Constructions) . . . . 17
Parts Kits
19
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Parts List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
W4589 / IL
Figure 1. EHA Series Valve with Type 657 Actuator
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Introduction
Only persons qualified through training or experience should install, operate, and maintain a Design EHAD, EHAS, or EHAT valve. If there are any questions about these instructions, contact your Fisher Controls sales office or sales representative before proceeding.
Scope of Manual
Description
This instruction manual includes installation, maintenance, and parts information for the Class 1500 Design EHAD, EHAS, and EHAT control valves in 3through 8-inch valve body sizes. Refer to separate manuals for instructions covering the actuator, positioner, HIGH-SEAL packing, and accessories.
The Design EHAD, EHAS, and EHAT high-pressure angle valves (figure 1) have metal seats, cage guiding, and push-down-to-close valve plug action. The Design EHAD and EHAT valves use balanced valve plugs. The Design EHAS valve uses an unbalanced valve plug. To provide a seal between the cage and a
C-seal is a mark owned by Pressure Science, Inc. Cavitrol, Fisher, Fisher-Rosemount, HIGH-SEAL, Managing The Process Better, and Whisper Trim are marks owned by Fisher Controls International, Inc. or Fisher-Rosemount Systems, Inc. All other marks are the property of their respective owners.This product may be covered by one or more of the following patents: 5,129,625; 5,131,666; 5,056,757; 5,230,498; and 5,299,812 or under pending patents.
Fisher Controls International, Inc. 1986, 1996; All Rights Reserved
D101297X012
Parts Ordering . . . . . . . . . . . . . . . . . . . . . . . . . . .