Instruction manual

Instruction Manual

D500240X012

A31A Valve

October 2012

For valves with tangential pins and/or disk p ins, locate the tangential pins (key 26) in the drive shaft (key 3) and the

disk pin (key 26) in the follower shaft (key 4).

a. If a maintenance kit is available, use the pin extractor to remove the disk pins. Select the correct size pin extractor

tip with screws of proper thread size to match the thread size in the disk pins. If a maintenance kit is not

available, see steps c and d below.

b. Screw the pin extractor tip into the pin as far as possible. With an upward, straight sliding motion, pull out the

pin. Repeat the same procedure for the other pins.

c. Use a threaded rod with an appropriate spacer and nut as an extractor tool. If using a threaded rod, choose a rod

with threads that fit the inside thread of the pins. The rod should extend several inches above the disk when it is

screwed into a pin.

d. After screwing the rod into the pin, slide t he spacer overtherodandpin.Threadthenutontotherodandtighten

it. As the nut is tightened, the nut will drive the spacer against the disk. The increasing force will draw the pin

from the disk.

7. Valves with a two-piece shaft have a gasket retainer and gasket (keys 20 and 21) on the follower shaft side of the

valve. Remove the hex head bolts and lockwashers (keys 23 and 22) from the gasket retainer and remove the gasket

retainer and gasket to expose the end of the follower shaft.

8. Support the valve disk properly, and remove the follower shaft. Pull the follower shaft from the valve body. Use a

shaft extractor screwed into the puller hole in the end of the follower shaft.

9. Support the valve disk properly, and remove the drive shaft. Pull out the drive shaft (key 3) by hand-pulling or by

using a shaft extractor screwed i nto the end of the shaft.

CAUTION

To avoid damage to the disk, seal ring, and T-slot area, do not force the disk past the seal or T-slot area. Remove the disk

from the opposite side of the valve body.

10. After removing the shaft(s), remove the disk and the thrust bearings. Do not force the disk past the seal ring or

T-slot area.

11. Remove the journal bearings (key 7). Using a suitable punch or puller, drive or pull the journal bearing(s) into the

valve body bore from the drive shaft bearing bore. Do not attempt to remove the bearing stop (key 8). Remove the

journal bearing from the follower shaft bearing bore.

12. Inspect the valve body bore, bearings, bearing bores, and packing box for damage.

Installing a One-Piece Shaft

Unless otherwise indicated, key numbers and part names are listed in figure 8.

1. Secure the valve in an upright position. Allow for easy access to the valve body bore. Allow for easy access to the

drive shaft bearing bore.

2. Inspect all parts removed from the valve for wear or damage. Replace any worn or damaged parts. Clean the valve

body and all parts to be installed with an appropriate solvent or degreaser.

CAUTION

Premature valve failure and loss of process control may result if bearings are improperly installed or are damaged during

installation.