LowFlow Mark 708ME Series with Motor Valve - Manual (Page 2)

may be dressed with a very fi ne crocus cloth, but
generally it is best not to as the stem has a fi ne ma-
chined fi nish. Use approved non-residue-forming
solvent for cleaning. Wipe dry with clean cloth.
3. Insert a new set of packing in packing box. Press
each ring down in place with a tube as it is in-
stalled.
4. After packing is installed, assemble packing adapt-
er, gland, and gland nuts. Tighten the nuts hand
tight.
5. The fi nal packing adjustment should be made with
the valve pressurized and the packing tightened
just enough to stop any leakage, while stroking the
valve. Excessive tightening could cause the stem
to stick and result in improper valve operation
due to high friction forces.
Removing Actuator from Valve
1. Position the valve to full open and disconnect all
electrical connections.
2. Remove the actuator from the valve as follows:
loosen the two stem connector nuts and move
them down the stem. Lock these nuts together.
Remove the two nuts that secure the packing
fl ange, then the then the two hex bolts that secure
the yoke to the bonnet. Remove the gland nuts (11)
that secure the packing gland (9) and the packing
adaptor (7). Using a wrench on the nuts and on
the fl ats of the actuator stem, turn the stem con-
nector (while holding the actuator stem in place)
until the stems disengage. The actuator will be free
of the valve.
Body & Bonnet Disassembly
1. For actuator removal, refer to section on “Removing
Actuator”.
2. Remove the body/bonnet bolts and carefully sepa-
rate the body from the bonnet so as not to damage
delicate trim components.
3. Remove stem nuts and indicator. Withdraw the
stem and plug out of the bonnet. (The smaller trims
have a one-piece stem and plug, which can be
withdrawn through the packing.)
4. With a socket wrench, remove the seat from the
body. Remove and discard the body/bonnet gas-
ket.
5. Soft seats are disassembled by removing the seat
cap from the seat and then the soft seat can be
removed.
6. Clean all parts with an approved non-residue-form-
ing solvent. Remove encrusted material with a very
fi ne Crocus or aluminum oxide cloth. However, do
not use these abrasives on the seating surface or
the trim surface (the portion of the plug that enters
the seat bore.) The machining tolerances on these
surfaces are so closely controlled that you might
change the valves fl ow characteristic.
7. Inspect all parts and replace and worn or damaged
parts. It is always advisable to replace seals and
2. The control valve has been pre-set by Jordan Valve,
however, fi ner 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 down stream line, fully
open the outlet valve. Slowly open the inlet valve
just enough to start fl ow through the control valve.
Increase the fl ow 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 fl uid, close the inlet shutoff
valve fi rst, and then close the outlet shutoff valve.
Maintenance
Caution: Make certain that there is no pressure in the
valve before loosening any fi ttings 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 fl ow
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 docu-
ment for description and proper orientation of parts.
To reduce maintenance time, refer to proper fi gure and
follow steps indicated below for applicable maintenance
operation.
Proposed Maintenance
Procedure
Follow Steps...
Renewing Stem Packing Packing Replacement
Valve Disassembly,
Inspecting Parts, Replacing
Plug or Seat Ring
Valve Disassembly
Valve Reassembly Valve Reassembly
Motor Valve Seat Spring
Preload
Motor Valve Seat Spring
Preload
Packing Replacement
Renew valve plug stem packing if control valve has been
in service beyond normal maintenance, and packing
shows signs of wear. Wear will be indicated by leakage,
which cannot be corrected by minor tightening of the
packing fl ange. An additional packing ring can be in-
stalled to overcome minor leakage without dismantling
the control valve or breaking valve plug connection.
1.
Remove the actuator from the bonnet. (See Remov-
ing Actuator from Valve.)
2. Remove all of the packing and discard. Clean valve
stem and packing box thoroughly. The valve stem
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