8
Slurry Series
Operation and Maintenance Manual
14. Install the second seat. Using a straight edge, check the seat position in four places, 90 degrees apart in relation to
the replaced seat bore I.D. Adjust as required to make the seat concentric with the other seat.
15. Repeat Step 12.
16. Install the seat retainer with retainer screws and tighten down the retainer and seat to the point that the retainer
screws can be engaged by hand. For sizes 14” and above, it may be necessary to use two C-clamps on opposite sides
to pull down the seal retainer.
17. Install the retainer screws and tighten sufficiently to allow installation of the next screw. Continue this until all screws
are installed.
18. Remove C-clamps, if used.
19. The valve is now ready for installation. The gate must remain in the open position until the valve is installed and ready
for operation.
Relieve line pressure before attempting to remove the valve from the line to avoid personnel injury and/or equipment
damage. If the valve has a pneumatic actuator, solenoid valve, limit switches, or other accessories, disconnect the electri-
cal and pneumatic supply.
Seat Replacement (No Retainer - Series 765, 766, and 768)
1. Relieve the line pressure and close the valve. Flush the line if necessary.
2. Remove the valve from the line by loosening the flange mounting bolts, studs, and nuts.
3. Clamp the valve in the vertical position up to 12” & in the horizontal position for the sizes above 12” to a fixture. Do
not block the valve port when clamping the valve. An over¬head hoist may be needed for larger size valves.
4. Retract the gate to full open condition.
5. Remove the seats (8) from the valve.
6. Verify that the circular bore is clear of all debris, scale, and elastomer residue.
7. Lay the valve down in a horizontal position on a flat surface.
8. Lubricate the O.D. and sealing lip of the first seat. Use recommended lubricants
9. Install the seat (8), being careful to center the flange end in the bore of the housing.
10. Lubricate the O.D. and sealing lip of the second seat. Use recommended lubricants
11. Install the second seat. Using a straight edge, check the seat position in four places, 90 degrees apart in relation to
the replaced seat bore. Adjust as required to make the seat concentric with the other seat.
12. The valve is now ready for installation. The gate must remain in the open position until the valve is installed and ready
for operation.
ACTUATOR MAINTENANCE
Pneumatic Cylinder
The Bray/VAAS pneumatic cylinder actuator is a low maintenance design and does not require routine maintenance. It has
an FRP tube which is lubricated for life with a special coating on the inside wall. Filtered dry, instrument quality air (non-
lubricated) should be used for its operation at the specified air supply pressure.
