Cla-Val 61-02/661-02 Technical Manual - Manual (Page 11)

When block and tackle or a power hoist is to be used to lift the valve cover
insert a proper size eye bolt in place of the center cover plug. Pull cover
straight up to keep from damaging the power unit stem bearing and upper
stem.
On valves 1" and larger remove the power unit retaining nuts. The power
unit body can now be lifted from the valve body. The stem with diaphragm
assembly and disc retainer assembly will be removed with the power unit
body.
CAUTION: During service performed on the stem assembly, the stem sur-
faces must not be damaged. If a vice or other holding device is used to grip
the stem, soft jaws of brass or copper must be used to protect the precision
ground surface of the stainless steel stem. If the stem is marred no amount
of careful dressing can restore the stem to its original condition.
REASSEMBLY
To reassemble, reverse the order of disassembly.
1. If the disc has been removed, it is important that correct pressure be
on the disc from the disc guide when the lower stem nut is tight. Use suf-
ficient spacer washers to obtain slight pressure (by visual indentation) on
the disc. This applies to 1" through 16" valves. Refer to seat and disc
detail drawings for location of spacer washers for various valve sizes.
Note: New discs will usually require a different number of spacer wash-
ers to obtain the right amount of 'grip (slight indentation) on the disc.
6. Inspect the threads on the stem. Mineral deposits that prevent the
nuts from turning must be cleaned from the threads A 5C.h solution of
muriatic acid will soften mineral or scale deposits to assist in removal of
nuts and general cleaning of parts. Flush the parts thoroughly with water
immediately after cleaning.
Care must always be exercised when handling acid. Read the warning
label on the acid container to be sure of correct method of use and dis-
posal after use.
7. Remove the upper stem nut, upper diaphragm washer, diaphragm
and lower diaphragm washer. The stem with the disc retainer assembly
can now be removed from the power unit body
8. Hold the stem in a vice with soft jaws and remove the lower stem nut.
Remove the lock washer, disc retainer, space washer(s) and disc Refer
to the sectional view of the valve size being serviced. This will assist in
the disassembly procedure outlined above. The reassembly instructions
outlining proper procedure and quantity of space washers. This is espe-
cially important if the disc is replaced.
Inspection of Parts
1. Returning to the valve body in the line, the seat should now be
inspected for damage. if the seat requires removal use the following
tools. Seats in valve sizes 1/2" and 3/4" can be removed with a hex sock-
et wrench. Seats in valve sizes 1" through 6" should be removed with
accessory X-109 Seat Removing Tool available from the factory. Seats
in valve sizes 3" through 16" may be removed with a screw driver. If upon
removal of the screws the seat cannot be lifted out, it will be necessary
to use a hard rubber mallet and tap the seat loose.
2. Any buildup of mineral or scale should be cleaned from the valve body
at this time. Inspection of the cover and power unit body surfaces that
contact the diaphragm is important. Clean and smooth, with wet or dry
emery paper, any roughness that could damage the diaphragm. Inspect
and recondition the surface on the upper and lower diaphragm washers.
The perimeter of the diaphragm washers is the most likely area to cause
diaphragm wear if the surface is not smooth. Take extra care to make
this a smooth finish.
3. Inspect the power unit body bearing insert o-ring that is in contact with
the stem. If it is worn, nicked or cut, replace it.
4. Inspect the diaphragm for cracks or chafing. Replace the diaphragm
if damaged.
Inspect the disc and replace if the surface is damaged or worn. If a new
disc is not available, the existing disc can be turned over, exposing the
unused surface for contact with the seat.
6. The disc guide should be checked and cleaned of scales and mineral
deposits. Due to the close tolerance between the outer periphery of the
disc guide and the inner area of the valve seat, no scale or mineral
deposits should be overlooked.
Valve Cover
Hammer
Dull Cold Chisel
(Angle upward as
much as possible)
MAINTENANCE
Preventative Maintenance
The Cla-Val Co Powertrol Valves require no lubrication or packing
and a minimum of maintenance. However, a periodic inspection
schedule should be established to determine how the fluid velocity
as well as the substances occurring in natural waters are affecting
the valve These substances can be dissolved minerals. colloidal
and suspended particles. Effect of these actions or substances must
be determined by inspection.
DISASSEMBLY
1. First mark the side of the valve cover, power unit body and valve body so
that reassembly of these parts will be exactly as removed.
2. The Powertrol Valve inspection or maintenance can be accomplished
without removal of the valve body from the line. Shut off pressure to the
valve, both inlet, outlet and independent operating pressure when used.
WARNING: Maintenance personnel can be injured and equipment and prop-
erty damaged if disassembly is attempted with pressure in the system.
3. After pressure has been released from the valve control system and oper-
ating chambers of the valve, remove the controls and tubing. Obtain a
schematic of the assembly or note and sketch position of tubing and controls
for reassembly. Replacing tubing into the control ports exactly as removed is
necessary. Failure to reassemble properly will cause the valve to malfunc-
tion and possibly cause serious damage.
4. Remove cover nuts and cover. if the valve has been in service for any
length of time, chances are the cover will have to be loosened by driving
upward along the edge of the cover with a dull cold chisel. See Figure 1.