Emerson Fisher EWD, Instruction Manual

Page: 26 / 60

Instruction Manual
D100399X012
EW Valve
July 2017
26
Figure 14. Example of Machining the Lower (Valve Plug to Seat Ring) and Upper (C‐seal Plug Seal to Cage) Seating
Surfaces
UPPER SEATING
SURFACE
C‐seal
RETAINER
MACHINING OF THE UPPER
SEATING SURFACE MUST
EQUAL THE TOTAL MACHINING OF
THE LOWER SEATING SURFACE
(PLUG PLUS SEAT RING). IF NOT, THE
RETAINER MAY STRIKE THE UPPER
SEATING SURFACE BEFORE THE
VALVE PLUG PROPERLY SEATS ON
THE LOWER SEATING SURFACE.
LOWER SEATING SURFACE
PLUS
SEAT
RING
PLUG
CAGE
A6781 / IL
1
3
2
1
2
3
NOTE:
0.508 (0.020)
(4)
0.254 (0.010)
(4)
0.254 (0.010)
(4)
REMOVAL OF 0.254 mm (0.010 inch) FROM THE VALVE PLUG
REMOVAL OF 0.254 mm (0.010 inch) FROM THE SEAT RING
REMOVAL OF 0.508 mm (0.020 inch) FROM THE UPPER
SEATING SURFACE IN THE CAGE
4. THESE VALUES ARE FOR EXAMPLE ONLY. REMOVE ONLY THE MINI­
MUM AMOUNT OF MATERIAL REQUIRED TO REFURBISH THE SEATS.
Trim Replacement (C‐seal Constructions)
1. Apply a suitable high‐temperature lubricant to the inside diameter of the C‐seal plug seal. Also, lubricate the
outside diameter of the valve plug where the C‐seal plug seal must be pressed into the proper sealing position
(figure 9).
2. Orient the C‐seal plug seal for correct sealing action based on the process fluid flow direction through the valve.
D
The open interior of the C‐seal plug seal must face up in a valve with flow‐up construction (figure 9).
D
The open interior of the C‐seal plug seal must face down in a valve with flow‐down construction (figure 9).
Note
An installation tool must be used to properly position the C‐seal plug seal on the valve plug. A tool is available as a spare part from
Emerson or a tool could be manufactured following the dimensions given in figure 10.