Jordan Valve Mark 75 Series – Wafer Style Control Valve - Manual (Page 2)

(28), Disc (27), and Gasket (36). Place the plate on
the bench with the lapped surface up.
5. Clean all parts of the Body (1) with a good quality
solvent. Remove Guide screws (35) and Guides
(34), the Disc (27) and Plate (28) can then be
cleaned. Place a piece of 4/0 polishing cloth or
jeweler’s cloth on a smooth flat surface such as a
surface plate and polish the Disc, and Plate lapped
surfaces using a figure “8” motion. If the parts are
scarred, do not attempt to re-lap them, but return
them to the factory for repair or replacement.
B. Reassembly
1. Place the plate (28) on a clean, flat work surface
with the lapped side up. The small single locator
hole should be towards you.
2. If the valve action is “air to open”, place the Disc
(27) on the Plate with the words “TOP REVERSE”
away from you. If the valve action is “air to close”,
the words “TOP DIRECT” should be away from you.
Move the Disc (27) until the slots are in perfect
alignment with those of the plate (28).
3. Place the Guides (34) on either side of the Disc
(27), and secure them with the Guide screws (35)
so that the Disc (27) can move freely up and down
but not side to side.
4. Lightly lubricate both side of the Body Gasket (36)
with an anti-seize compound. Place a new Body
Gasket (36) into the Body (1).
5. Hold the Plate / Disc assembly together and insert
it into the large end of the Body (1) with the slots
perpendicular to the stem (20), taking care that the
“T” slot in the Disc (27) engages the head of the
valve stem. The word ”TOP” should be towards the
actuator.
6. Replace the Set screws (42) in the Body (1).
7. Follow instructions under Installation & Start Up
Procedure when placing valve back in service.
Stem & Packing Replacement
1. Remove the Plate (28) and Disc (27), following the
procedure outlined under the Valve Seats section.
2. Loosen the Stem Connector Nut (31) and Bolt (30)
and remove Connector Halves.
3. Back out the Yoke SST Screws (29) and allow the
Body (1) to separate from the Yoke (3).
4. Remove the Packing Flange Nuts (43) and the
Packing Flange (24).
5. Before pulling the Stem (20) completely out of the
Body, you must remove the “7th” Stem T-Head (32)
by unscrewing it from the Stem (20). Remove the
Packing Assembly (37,38, & 40). The remaining
parts of the Packing Assembly can “fished” out with
a small screwdriver. (Be careful not to damage the
packing bore.)
6. Clean the packing bore in the Body with solvent
and blow dry.
2. The control valve has been pre-set by Jordan Valve,
however, finer adjustment may be required to com-
pensate for the system conditions of your applica-
tion.
3. With inlet, outlet and bypass shutoff valves closed,
and no pressure in the downstream line, gradually
open the inlet valve enough to start flow through
the control valve. Increase the flow gradually by
slowly opening the inlet shutoff valve. Do not fully
open the inlet valve until you are sure that the
controller and control valve have control of the
system. Usually, the handwheel on the inlet valve
will turn freely when this point is reached.
4. To shut off the line fluid, close the inlet shutoff
valve first, and then close the outlet shutoff valve.
5. Loosen the body set screws (42).
6. It may be necessary to re-torque the pipe flange
bolts.
Maintenance
Caution: Make certain that there is no pressure in the
valve before loosening any fittings or joints. The fol-
lowing steps are recommended:
1. Close the inlet shutoff valve.
2. Allow pressure to bleed off through the down-
stream piping. Do not attempt to reverse the flow
through the valve by bleeding pressure from the
upstream side of the valve.
3. When the pressure gauges indicate that all pres-
sure has been removed from the system, close the
outlet shutoff valve and the valve may be serviced.
Note: refer to the drawing at the end of this document
for description and proper orientation of parts.
Valve Seats
A. Disassembly
The sliding Gate Seats of Jordan Valves are lapped to
light band flatness. Maintaining such tolerances is of
paramount importance for your assurance of excellent
control and tight shutoff. DO NOT use metallic objects
in removing the seats. Care in handling is imperative.
1. Tighten the body set screws (42). Follow instruc-
tions under the Maintenance section to remove
valve from line.
2. Disassemble the valve only as far as necessary to
do the required work.
3. When replacing seats it is recommended by Jordan
Valve that the packing be replaced if the valve is
older than one year. Follow the instructions under
Packing Replacement.
4. Remove the Set screws (42), and remove the Plate
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