Air Piping; Disassembly - Emerson Fisher Baumann Little Scotty 24000C Instruction Manual

24000C Valve
February 2019

Air Piping

1. For an air-to-extend actuator (air-to-close action), connect the actuating air pressure line to the 1/4 NPT opening in
the upper diaphragm case. For an air-to-retract actuator (air-to-open action) connect the actuating air pressure line
to the 1/4 NPT opening in the lower diaphragm case.
2. Use 6.4 mm (1/4 inch) O.D. tubing or equivalent for all air lines. If air line exceeds 8 m (25 ft) in length, 9.5 mm (3/8
inch) tubing is preferred. Air pressure should not exceed 2.5 barg (35 psig).
CAUTION
D When assembling or disassembling the valve, do not turn the valve stem while the plug is touching the valve seat. This
will damage the valve's seating surfaces.
D When adjusting the valve stem do not grip the stem directly with pliers or a wrench. This will damage the surface of the
stem, and cause damage to the packing in the valve. Instead, counter-tighten the two locknuts (key 27) on the stem
(key 5). This will allow you to turn the stem by turning the locknuts (key 27) with a wrench.
D When placing valve in a vise, clamp the flat end faces of the valve. Do not clamp the rounded sides of the valve. This will
distort the shape of the casting, and will ruin the valve.

Disassembly

1. Mount the valve in a vise by clamping flat end faces of the valve (figure 3). Caution must be taken not to damage
the serrated flange faces.
2. Remove the actuator, stem locknuts (key 27), travel indicator (key 58)) and yoke drive nut (key 9).
3. Turn the bonnet (key 8) in a counter-clockwise direction from the valve body (key 1). Remove the O-ring (key 12)
and remove and discard the valve body gasket (key 49). A new gasket should be installed each time the valve is
disassembled.
4. Pull the plug and stem assembly (keys 4 and 5) out through the bottom of the bonnet. Rotate the assembly to
prevent damage to the packing. Wipe the parts with a clean soft cloth and examine for signs of wear.
CAUTION
Handle the parts carefully to avoid damaging the seating and guiding surfaces.
5. Use a seat ring tool made according to the dimensions in figure 2 and table 1 to remove the seat ring (key 2) as
follows:
a. Insert the tool into the valve body. Be certain the tool lugs are engaged in the corresponding recesses in the seat
ring.
b. Use a 1/2 inch drive breaker bar or impact wrench having sufficient torque capability to remove the seat ring.
Seat ring installation torque is provided in table 2 for reference. Connect the breaker bar or impact wrench, and if
needed, a impact-rated extension bar, to the square drive of the seat ring tool.
c. Remove the seat ring (key 2) from the valve body. Make sure the seat ring tool is held at a right angle to the seat
ring during removal to prevent the tool from disengaging from the lugs of the seat ring.
d. Inspect parts for wear or damage that would prevent proper operation of the valve body.
4
Instruction Manual
D103356X012