AVK 41 Series User manual

American AVK Company
An ISO 9001 registered company
Maintenance Manual Series 41
*Subject to change without notice. (rev. 06/20 H)
AVK SERIES 41 SWING CHECK VALVE
FIELD MAINTENANCE AND INSTRUCTION
MANUAL FOR SWING CHECK VALVES 3" - 12"
TABLE OF CONTENTS
EXPLODED ASSEMBLY / PARTS LIST
INTRODUCTION / DESCRIPTION
RECEIVING AND STORAGE
INSTALLATION
- SWING
- LEVER AND WEIGHT
- LEVER AND SPRING
MAINTENANCE
TROUBLESHOOTING
DISASSEMBLY FOR INSPECTION
RE-ASSEMBLY AFTER INSPECTION
REPAIR PROCEDURES
- HEAD REPLACEMENT
- SEAL REPAIR KIT
- SEAL/DISC KIT
OPTIONAL EQUIPMENT
- PRIMING/BACKFLOW ACTUATOR (OPTIONAL, 3-inch through 8-inch)
PARTS AND SERVICE
WARRANTY
AMERICAN AVK COMPANY

page 1
American AVK Series 41 Swingcheck Valve
Exploded Parts Breakdown
3-inch through 8-inch
2014 New Style Bonnets
Components: 400. Body 401. Disc Nut* 402. Disc Washer 403. Disc Bushing 404. Hinge 405. Bonnet Washer 406. Bonnet Bolt 407. Bonnet 408. Shaft 409. Key 410. Lock Washer 411. Hinge Bolt 412. Bonnet Gasket 413. Disc 414. Shaft Nut 415. Shaft Washer 416. Lever 417. Open Bushing 418. Inner Bushing O-ring 419. Weight 420. Set Screw 422. Closed Bushing 429. Bonnet O-RIng** * As of March 1st, 2008 on 3" through 8" valves, the Disc Lock Washer and Disc Nut are replaced by a self locking Disc Nut. ** As of June 2014, additional o-rings included in new style bonnet assemblies fo 3" through 8" valves.
409 408 422
406 405 414 415 418 416 417 420 419 412 410
413411404403402401400
407 429

page 2
Item No. Description Material
400 Body Ductile iron, ASTM A536
401 Disc Nut 304 Stainless steel
402 Disc Washer 304 Stainless steel
403 Disc Bushing Polymide 6.6
404 Hinge 316 Stainless steel
405 Bonnet Washer 304 Stainless steel
406 Bonnet Bolt 304 Stainless steel
407 Bonnet Ductile iron, ASTM A536
408 Shaft Optional 420 or 316L Stainless steel
409 Key 304 Stainless steel
410 Lock Washer 304 Stainless steel
411 Hinge Bolt 304 Stainless steel
412 Bonnet Gasket EPDM rubber
413 Disc EPDM encapsulated steel disc
414 Shaft Nut 304 Stainless steel
415 Shaft Washer NBR
416 Lever Ductile iron ASTM A536
417 Open Bushing Brass
418 Inner Bushing O-ring NBR
419 Weight Ductile iron, ASTM A536
420 Set Screw 304 Stainless steel
422 Closed Bushing Brass
423* Disc Lock Washer 304 Stainless steel
424 Spring Stainless Steel
425 Spring Eyebolt Stainless Steel
426 Spring Eyebolt Nut Stainless Steel
427 Spring Eyebolt Washer Stainless Steel
428 Spring Bracket Carbon Steel
429** Bonnet O-ring NBR
430 Hinge Connector 10"-12" Stainless Steel
431 Retaining Washers 10"-12" Stainless Steel
432 Shaft Spacers 10"-12" Stainless Steel
433 Spring Arm Washer 10"-12" Stainless Steel
434 Spring Arm Nut 10"-12" Stainless Steel
435 Spring Arm rod 10"-12" Stainless Steel
436 Spring Bracket Mount Bolt 10"-12" Stainless Steel
437 Spring Arm Spacer 10"-12" Stainless Steel
438 Priming Actuator Seal Washer Fiber
439 Priming Actuator Body Brass
440 Priming Actuator O-ring NBR
441 Priming Actuator Spindle Stainless Steel
442 Priming Actuator Handle Stainless Steel
446 Bonnet Plug Bolt 10"-12" Stainless Steel
447 Bonnet Plug Washer 10"-12" Copper
448 Shaft Lock Washer 10"-12" Stainless Steel
449 Spring Bracket Mount Washer Stainless Steel
For individual part ordering, refer to the item number, size & conguration of the valve when contacting American AVK Customer Services
Note: Items (#401) through (#423) may be ordered as a replacement kit. ( Head Assembly ) Refer to "HEAD REPLACEMENT" on page
13. Specify the appropriate valve size and conguration when ordering.
*As of March 1st, 2008 on 3" through 8" valves, the Disc Lock Washer and Disc Nut are replaced by a self locking Disc Nut.
**As of June 2014, additional o-rings included in new style bonnet assemblies fo 3" through 8" valves.

page 3
INTRODUCTION / DESCRIPTION
The American AVK Series 41 Swing Check Valve is designed to be a trouble free, easy to maintain check valve. This manual will
provide you with the information needed to properly install and maintain the valve and to ensure a long service life. The valve is opened by
uid ow in one direction and closes automatically to prevent ow in the reverse direction. An optional priming actuator may be mounted on
the bottom of the valve to allow manual priming through the valve in the reverse direction for sizes 3- through 8-inch. An optional limit open
device is available for sizes 10-inch and 12-inch. The Size, Flow Direction, and Maximum Working Pressure are cast into the body of the
valve for reference.
RECEIVING AND STORAGE
Inspect valves upon receipt for damage in shipment. Unload all valves carefully to the ground without dropping. Do not allow lifting
slings or chains to pass through the valve; use eyebolts or rods through the ange holes on large valves. Never lift a valve by the lever and
weight assembly or lever and spring assembly as this may damage the valve. Valves should remain crated, clean and dry until installed to
prevent weather related damage. For long term storage the valves should be stored indoors.
INSTALLATION
WARNING: The line must be isolated, depressurized, and drained before removing the valve bonnet or removing the
valve from line. Failure to do so may cause pressure to be released resulting in severe injury or death.
Correct installation of the Series 41 Check Valve is important for proper operation. It may be installed in either
horizontal or vertical ow-up applications. If installed in the vertical ow-up position, a lever and weight or lever and spring
assembly must be used to ensure proper valve operation. See gures 2, 3 and 4 for proper positioning of the lever and weight
for horizontal and vertical ow-up applications. In all installations, the ow arrow cast in the valve body must be pointed in
the direction of ow during normal system operation.
Flanged valves should only be mated with at-faced pipe anges equipped with full face resilient gaskets. The valve
and adjacent piping must be supported and aligned to prevent cantilevered stress on the valve. Once the ange bolts or studs
are lubricated and inserted around the ange, tighten them uniformly hand tight. The tightening of the bolts should then be
done in graduated steps using the crossover tightening method. The appropriate torques are listed in table 1. If leakage
occurs, allow gaskets to absorb uid and check torque and leakage after 24 hours. Do not exceed bolt rating, extrude gasket,
or compress gasket more than 50% of it's thickness. When torque values are specied in this manual, AVK advises the use of
torque wrenches when required.
Note: Flange mounting bolts must be installed with nuts on the Swing Check Valve ange side.
Valve Diameter (Inches) Bolt Diameter (inches) Recommended Torque (ft-lb)
3 5/8 30
4 5/8 35
6 3/4 35
8 3/4 50
10 7/8 60
12 7/8 70
Table 1
Recommended Flange Bolt Torque Values

page 4
Top View
Direction of Flow
Fig. 2
Horizontal Mounting
Front View

page 5
Fig. 3
Vertical Mounting
Direction
of
Flow
Rear View Front View

Open Position
Closed Position
Open Position
Closed Position
page 6
Fig. 4
Optimal Leverage
Congurations
Horizontal Mounting
Vertical Mounting
Direction
of
Flow
Direction of Flow

416 414 420415 419
page 7
INSTALLATION - continued:
SWING
A valve without a lever is referred to as ‘Swing’. For Swing installation, follow the "INSTALLATION" instructions on page 3 .
LEVER AND WEIGHT (OPTIONAL)
Once the valve is properly installed, the lever and weight assembly needs to be attached to the Shaft (408) passing
through the Open Bushing (417) in the Bonnet (407). Slide the Lever (416) onto the Shaft (408) and position as shown in
gure 4. Secure the Lever with the Shaft Washer (415) and Shaft Nut (414) and tighten to 30 ft-lbs. Attach the Weight (419)
and tighten the Set Screw (420) to hold the weight in place. A medium strength thread locking compound such as Locktite 242
should be used to attach the Lever and Weight.
WARNING: The weight can be moved on the lever to adjust closing speeds for optimum performance. DO not adjust
the weight while the system is operation. Serious injury can occur.
Fig. 5
Lever & Weight Mounting
Direction of Flow

416
427
414
424
415
425
426
426
427
428
page 8
INSTALLATION - continued:
LEVER AND SPRING 3"- 8" (OPTIONAL)
For sizes 3-inch through 8-inch, the Spring Bracket (428) must be installed using the ange mounting hardware
(gure 6). Install the Spring Eyebolt (425) on the Spring Bracket, securing it with the Spring Eyebolt Nuts (426), and Spring
Eyebolt Washers (427), one washer and nut on each side of the Spring Bracket (428). Slide the Lever (416) onto the Shaft
(408) and position as shown in gure 4. Secure the Lever with the Shaft Washer (415) and Shaft Nut (414) and tighten to 30
ft-lbs. Attach Spring (424) in it's relaxed position as shown in gure (6).A medium strength thread locking compound such as
Locktite 242 should be used to attach the Lever.
Fig. 6
Lever & Spring Mounting
3" - 8"
Direction of Flow

422 412 429 407 430 409 423 413 408 431 432 417 418 416 415 414 433 434 435
436 424 426 425 437 427 428
448
449
page 9
INSTALLATION - continued:
LEVER AND SPRING 10"-12" (OPTIONAL)
For Lever and Spring equipped 10-inch and 12-inch swing check valves, the Lever and Spring Assembly is installed
at the factory.
Fig. 7
Lever & Spring Mounting
10" - 12"
Bent Tab on
Lock Washer