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EXTENSION KITS: Fig. 10
American AVK Hydrants have the capability of adjusting the Lower Barrel to the proper height due to changes in the
finished grade. Extension Kits are available from 6” to 90” in 6” increments. ( Longer upon request) 

WARNING: On a partially disassembled hydrant under line pressure, pressing down on the stem could force open the Main
Valve (F61) and allow it to slam shut, creating a water hammer. If the intention is to remove the Main Valve (F61) first locate
and be sure the supply valve is closed. Relieve the pressure on the Main Valve (F61) by momentarily opening and then closing
the hydrant. 

NOTE: Only one extension kit of the proper size may be installed on a hydrant. Multiple extension kits on a single hydrant
may impede hydrant operation. Only extension kits manufactured by AVK should be used on AVK fire hydrants. Non AVK
extension kits may impede hydrant operation. 

The installation is performed as follows: 

1. Remove the Weathershield Retaining Bolt (F1) with an 5/16” or (8mm) hexagon key. Lift off the Weathershield (F2). 

2. Remove the Lock Plate Retaining Screw (F3) and Lock Plate (F4) with a 7/64” or (3mm) hexagon key. Note: Older
hydrants may be equipped with a set screw instead of lock plate. Remove the set screw and set aside for later use. 

3. Remove the Thrust Nut (F6) using the AVK operating wrench and rotating counter clockwise. Remove the upper Anti
Friction Washer (F8). 

4. Remove the Operating Nut (F10) using the AVK operating wrench. Turn counterclockwise for “Open Left Hydrants”, and
clockwise for “Open Right Hydrants”. Remove the lower Anti Friction Washer (F8) and set aside with the operating nut. 

5. Using the socket wrench end of the AVK T-wrench, remove the Stop Nut (F11) from the Upper Stem Rod (F16). 

6. Remove the six Bonnet Bolts (F12), Nuts (F18), and Washers (F13), using a 3/4” or (19mm) wrench. Lift Bonnet (F14)
straight up over the Upper Stem Rod (F16), carefully to avoid damage to the Stem Seal O-rings (F15). 

7. Remove the Barrel Gasket (F17), and inspect it for damage. If damaged, replace. 

8. Remove the four Nozzle Section Bolts (F30), Nuts (F34), and Washers (F31), using 15/16″, or 24mm wrenches. Carefully
lift the Nozzle Section (F29) off of the lower assembly.
NOTE: For series 27 dry barrel hydrants manufactured after Feb. 18, 2011, hydrants with buries from 3′ to 7′ include Hydrant
Bury Tags (F94). 

9. Remove the lower Spring Pin (F38) and slide the lower Coupler Pin (F36) from the Lower Stem Rod (F41). Disconnect
the Upper Stem Rod (F16) along with the Stem Rod Coupling (F37) from the Lower Stem Rod (F41). Inspect
the Stem Rod Coupling for damage and replace if necessary. 

10. Remove the Breakable Flange (F33), and Lock Ring (F32). Set aside for later re-assembly. 

11. Install a Standpipe Flange (F46) from the Extension Kit and reinstall the Lock Ring (F32).
NOTE: Ensure the Standpipe Flange is oriented correctly with the recessed side towards the Lock Rings. 

12. Slide the Spider (F39) down over the Extension Stem Rod (F48) and align the Spider Retaining Bolt (F40) with the
prepared hole. Tighten the Spider Retaining Bolt with a 11/16” or (17mm) wrench. Do not over tighten. As of Nov. 1, 2011,
the Spider and Spider Bolt are no longer required on AVK dry barrel hydrants. 

13. Install the Extension Stem Rod (F48) on the Lower Stem Rod (F41) with new Spring Pin (F38), Coupler Pin (F36) and
Stem Rod Coupling (F37). 

14. Clean the top of the Lower Barrel (F49) and install a Barrel Gasket (F17). 

15. If not already done, install a Lock Ring (F32) onto the lower groove of the Extension Barrel (F43). The top of the
Extension Barrel is marked with a Bury Line. 

16. Place the Extension Barrel (F43) onto the Lower Barrel (F49), making sure that the Barrel Gasket (F17) stays in place.
Slide the Standpipe Flanges (F46) until rest against the Lock Rings (F32). 

17. Align the bolt holes on the two Standpipe Flanges (F46) and install the Extension Barrel Bolts (F44), Nuts (F34) and
Washers (F31) as shown in Figure 10 and “Detail E”. Tighten to 80 Ft. Lbs.. 

18. Slide the Breakable Flange (F33) onto the Extension Barrel (F43). NOTE: The Breakable Flange must be installed so
that the wording “THIS SIDE UP” cast on the Breakable Flange are facing up. 

19. Reinstall the Lock Ring (F32) onto the Extension Barrel (F43). 

20. NOTE: (The following proceedure is for hydrants manufactured prior to Sept. 7, 2010.) Connect Upper Stem Rod
(F16) to Extension Stem Rod (F48) with Spring Pin (F38) and Coupler Pin (F36) and Stem Rod Coupling (F37).
Position the groove of the Stem Rod Coupling (F37) on the bottom, arrow pointing up. (See “Detail B”) 

21. For hydrants manufactured after Sept. 7, 2010, the new style stem rod coupling is used and there is no orientation
requirement. (See “Detail C”) 

22. Clean the top of the Extension Barrel (F43) and place a new Barrel Gasket (F17) on top. 

23. Carefully place the Nozzle Section (F29) on top of the Extension Barrel (F43) so that the Barrel Gasket (F17) is not moved or damaged

24. Slide the Breakable Flange (F33), against the Lock Ring (F32), (See “Detail D”) and align with the holes in the Upper Barrel (F35). Reinstall the Bolts, Nuts, and Washers removed in step 6. NOTE: For series 27 dry barrel hydrants manufactured after Feb. 18, 2011, hydrants with buries from 3′ to 7′ include Hydrant Bury Tags (F94). Extension Kits up to 4′ also include an Extension Bury Tag (F95). ( See “Detail A”) for installation locations. Tighten just hand tight. 

25. Clean the top of the Upper Barrel and place a Barrel Gasket (F17) on top. 

26. Carefully place the Modern Nozzle Section (F29) over the Upper Stem Rod (F16) taking care not to displace the Stem Seal O-rings (F15). Install the four Modern Nozzle Section Bolts (F71) and Washers (F31) removed in step 6, finger tight. 

27. Rotate the Modern Nozzle Section/Upper Barrel to align the nozzles to the desired position. Take care not to displace the two Barrel Gaskets. Tighten the nozzle section bolts connecting the Lower Barel to the Breakable Flange to 80 Ft. Lbs.. 

28. Using the socket portion of the AVK T-wrench, reinstall the Stop Nut (F11). Spin the stop nut down until it stops, and then snug it about 1/4 turn tighter. 

29. Reinstall the Anti Friction Washer (F8) in the oil reservoir of the Modern Nozzle Section Head (F29). 

30. If required, refill the lubrication reservoir in the Modern Nozzle Section (F29), reservoir with a food grade oil or grease that contains no acetate or silicone. 

31. Reinstall the Operating Nut (F10) . Tighten the Operating Nut all the way until it is snug against the lower Anti Friction Washer. 

32. Verify that there is a Lubrication Hole Seal (F9), installed in the threaded hole on the Operating Nut. Replace if missing. 

33. Reinstall the Anti Friction Washer (F8) on top of the Operating Nut (F10). 

34. Lightly grease the Thrust Nut O-rings (F5&F7), and reinstall the Thrust Nut (F6). Tighten the Thrust Nut until it is just snug against the Anti Friction Washer (F8), then back off the Thrust Nut 1/8 to 1/4 to the first location at which the Lock Plate (F4) can be installed. NOTE: DO NOT OVER TIGHTEN THE THRUST NUT (F6). 

35. Reinstall the Lock Plate (F4) and Lock Plate Screw (F3). On hydrants with equipped with a set screw, back off the thrust nut until the set screw can be reinstalled. 

36. Tighten the Modern Nozzle Section Bolts Bolts (F71) to 80 Ft. Lbs., using a star pattern. 

37. Reinstall the Weathershield (F2) and Weathershield Bolt (F1). 

38. Operate the hydrant into the fully open position and then close it fully prior to turning the lead valve on to allow the oil or grease to lubricate the operating nut. 39. Turn on the lead valve and operate the hydrant.