Flowserve Desuperheaters - Manual (Page 14)

Desuperheaters FCD VLENIM0115-00– 09/11
14
A
B
MaxCool MCX
Follow steps 1-10 and refer to Figures 1 and 4 to clean or replace the MaxCool MCX desuperheater
nozzle.
1. Depressurize the steam and cooling water lines. Drain the cooling water line and disconnect the
cooling water line from the desuperheater. Remove the desuperheater from the steam line.
2. Carefully grind off the tack welds between the nozzle assembly and the lance pipe connection.
3. Unscrew the nozzle assembly off of the lance pipe connection.
4. Remove expansion pin from plug. Unscrew castle nut. The MCX 025 has a regular nut and bent
washer in place of a castle nut and expansion pin. Unscrew retainer and remove spring. Remove
plug from seat.
5. If cleaning is required: With compressed air blow out the passageways of the nozzle openings and
clean the seat and plug surfaces. Inspect parts for wear, contamination, and blockage. Replace if
worn or broken.
6. To reassemble nozzle assembly install plug through seat. Install spring and screw on retainer. Set
maximum stroke of plug by screwing retainer until dimension B is met as shown in Figure 12 and
Table 5. After maximum stroke is set with retainer, screw on castle nut to lock retainer position and
reinsert expansion pin through plug. Be careful to retain stroke dimension during castle nut and
expansion pin assembly. On MCX 025 bend washer to lock nut.
7. Inspect lance for wear, leaks, or cracks. Replace or repair if necessary.
8. Install the nozzle assembly onto the lance pipe connection with torque values shown in Table 5.
9. Apply tack weld in two places to face of lance nozzle pipe connection by flats of nozzle assembly
seat. The tack weld should create bumps by the flats to keep nozzle assembly from unscrewing.
Care should be used to not apply weld to nozzle assembly seat. See Figure 13.
10. Install the desuperheater into the steam pipeline in the reverse order that it was removed.
Figure 12: Dimensions for Reassembly of Retainer