Nor-Cal Linear Gate Valve - Manual (Page 14)

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Nor-Cal Products, Inc., 1967 South Oregon St., Yreka, CA 96097 • Toll Free 800-824-4166 or 530-842-4457 • www.n-c.com Rev. 1-2013
V. Valve Adjustment
COMPRESSION AND OVER-CENTER 1.5” – 21”
A. Tools and Materials required:
1. Allen Wrench Set
2. Wrench Set (Box and Open)
3. Air Regulator
4. Heat Gun
5. Latex Gloves
B. Procedure:
Steps 1 through 8 apply to 1.5” and 3” Gate Valves only.
1. Actuate Valve to Open Gate position.
2. For safety, remove air from Actuator.
3. Remove Actuator Cover (2 screws)
4. Remove Actuator Top (6 screws)
5. Loose Jam Nut on Drive Shaft. This may require the use of the heat gun to melt the Lock-Tite on the thread. ((Def
Pro #51574 for high temp applications or Lock-Tite 242-31 for standard applications recommended) 0
6. Check Dimension A on Chart for specific valve size. (This is only the starting adjustment)
7. Adjust and tighten Jam Nut. (Do not use Lock-Tite at this point, as adjustment may be needed later)
8. Install Actuator Top, using only 2 to 4 screws.
9. Remove bolts holding the Bonnet Actuator Assembly to valve body. For Quick-Clamp Bonnet, undo the clamp.
10. Pull out Actuator Bonnet Carriage Assembly from valve body.
11. Check Dimension C on Chart for specific valve size.
12. To adjust, loosen Jam Nut, then turn Lower Linkage-Upper Linkage counter clockwise to increase dimension
for more compression, or turn clockwise to decrease the dimension for less compression. (More compression
means more air pressure to lock valve. Less compression means less air pressure to lock valve)
13. After adjusting, tighten Jam Nut to 5 ft-lb torque.
14. Reassemble Bonnet Carriage Assembly on valve body.
15. Using an in-line air regulator, check the air pressure required to lock valve. Refer to chart on next page for Rec-
ommended Locking Air Pressure per size of gate valve.
16. Adjust Dimension C until the correct Locking Air Pressure is achieved.
Steps 17 through 20 apply to 4” through 12”Gate Valves Only
17. Check Dimension B on Chart for specific valve size, depending on Overcenter or No Overcenter requirement.
(Note: Proper Overcenter means that the Gate does not drop when air pressure is removed from the Actuator)
18. If necessary, loosen nut and adjust Dimension B by turning screw counter clockwise to increase dimension for
less Overcenter or turn clockwise to decrease dimension for more Overcenter. Less Overcenter means less travel
for the Linkage; more Overcenter means more travel.
19. Check for Overcenter adjustment: If gate drops after removal of air pressure for valves that require overcenter, go
back to Step # 18.
20. Tighten nut.
21. Intall all bolts and tighten.
22. Test valve operation.