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

page 10
MAINTENANCE AND INSPECTION
The AVK Series 41 Check Valve requires no scheduled lubrication or maintenance. The valve can be serviced or
inspected without removal of the valve body from the line.
INSPECTION:
If inspection of the valve is required, follow the DISASSEMBLY FOR INSPECTION Instructions.
TROUBLESHOOTING:
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.
Several problems and solutions are presented below to assist you in troubleshooting the valve.
- Leakage at the shaft bushings ( Open Bushing (417), Closed Bushing (422) ) : Ensure that the shaft
bushings are properly tightened to 45-ft-lbs. If leakage persists replace the Inner and Outer Bushing
O-rings, (418,429) with an AVK Series 41 seal replacement kit.
- Leakage at the Bonnet: Ensure that the bonnet bolts are tightened to 45-ft;lbs. If leakage persists, replace
bonnet gasket (412).
- Valve leaks when closed: Remove and inspect disc for damage. Replace if necessary. Ensure that the
sealing surface in the valve body is clean and undamaged. NOTE: Per the AWWA C508 standard
for swing check valves, bronze seated valves do not seal drop tight.
- Valve does not open or close: Verify operating pressure is high enough to open the valve. Disassemble the
valve to check for an obstruction in the valve or pipeline.

406
429
403
407
401
405
417
412
408
409
402
410
413411
404
418
422
Fig. 8
Head Assembly Components
page 11
DISASSEMBLY FOR INSPECTION:
For convenience, the valve can be disassembled without removing it from the pipeline. All work on the valve should
be performed by a skilled mechanic with proper tools and a hoist for larger valves. Disassembly may be required to inspect
the disc for wear or the valve for deposits.
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.
1. Refer to Figure (8). If equipped with a lever and spring, disconnect the spring (424) from the lever (416).
If equipped with a lever and weight, the weights may need to be removed from the lever before the head
assembly can be removed. Remove the Bonnet Bolts (406), and Bonnet Washers (405) from the Bonnet
(407). Note bolt length when he bolts are removed. The bonnet bolts are di󰀨erent lengths depending
on location (upstream or downstream). The longer bonnet bolts are located upstream.
2. Pry the Bonnet (407) loose and lift o󰀨 the head assembly. Refer to Figure (8) for head assembly
components.
3. Inspect head assembly for worn or damaged parts. If resilient seated, inspect the disc for tears or cracks in
the EPDM coating.
4. Replace worn parts as necessary or replace head assembly with a new head assembly.

page 12
REASSEMBLY AFTER INSPECTION:
All parts and sealing surfaces must be cleaned before reassembly. Worn parts and seals should be
replaced prior to reassembly..
1. Lay the head assembly upside down on a clean surface so that the disc is up.
2. Place the Bonnet Gasket (412) in the groove in the Bonnet (407). Place a Bonnet Bolt Washer (405) on
each of the Bonnet Bolts (406). Carefully slide the bolts into the bolt holes and then through the
corresponding holes in the Bonnet Gasket. Ensure that the bonnet bolts are properly located by their
length. The longer bonnet bolts are upstream. The bonnet bolts will hold the Bonnet Gasket in place.
3. Pick up the head assembly holding the bolts and Bonnet Gasket in place and mount it on the valve body.
Ensure that the disc is facing the proper direction and that the Bonnet Gasket is not being pinched between
the bonnet and valve body.
4. Tighten the bonnet bolts to 45 ft-lbs incrementally in a crossover pattern to ensure that the bonnet does not
bend or crack and the bonnet gasket is evenly compressed.
5. If equipped with a lever and weight assembly, remount weights if necessary. If equipped with a lever and
spring assembly, reattach spring.

page 13
REPAIR PROCEDURES:
WARNING: For all of the following repair procedures, 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.
HEAD REPLACEMENT:
1. AVK can supply a complete head assembly for easy replacement. When ordering a new head assembly,
please refer to the check list below.
2. Remove the head assembly according to the ‘DISASSEMBLY FOR INSPECTION’ section.
3. Remove the Lever (416), if equipped, by removing the Shaft Nut (414), and Shaft Washer (415), and
place aside for later use.
4. Install the new head assembly according to the "REASSEMBLY AFTER INSPECTION" section. Install the
lever removed in step 3 above according to "LEVER AND WEIGHT" or "LEVER AND SPRING" installation
procedures.
AVK Series 41 Head Assembly Ordering Checklist
Valve Size:_____________ inches
Shaft Options: _____Swing _____Weight _____Spring
Lever Location ( Looking Downstream): _____Left-Hand _____Right Hand
Sealing Options: _____Resilient _____Bronze

422429418 407
412
417
Fig. 9
Seal Repair, Seal/Disc
Kit Components
402 413
403
401 404
page 14
REPAIR PROCEDURES - continued:
SEAL REPAIR KIT:
The Seal Repair Kit consists of two (2) Inner Bushing O-rings (418), two (2) Bonnet O-rings (429). The Inner Bushing
O-rings are not used on valves without a lever. 10-inch and 12-inch valves have Bonnet O-rings (429).
1. Remove the head assembly as described under DISASSEMBLY FOR INSPECTION above.
2. Remove the bushings. For valves with a lever, one bushing is open (417) and one bushing is closed (422).
For valves without a lever, both bushings are closed (422).
3. Remove the old O-rings from each bushing and replace with new O-rings.
a. Valve sizes 3-inch through 8-inch, without a lever, have Bonnet O-rings (429) only.
b. Valve sizes 10-inch and 12-inch without a lever have two two (2) Bonnet O-rings (429) only.
c. Valve sizes 10-inch and 12-inch, equipped with a lever, have two (2) Inner Bushing O-rings
(418), located inside the Open Bushing (417) and two (2) Bonnet O-rings (429).
d. 3-inch through 8-inch valves equipped with a lever, have two (2) Inner Bushing O-rings
(418) located inside the Open Bushing (417) and two (2) Bonnet O-rings (429).
4. Install the new O-rings as shown in gure (7) for 10-inch and 12-inch, gure (9) for 3-inch through 8-inch.
Installing the Inner Bushing O-rings (418) can best be accomplished with a good set of small picks. Be
careful not to cut the O-rings during installation.
5. Install the bushings in the valve Bonnet (407) and tighten to 45-ft-lbs.
6. Install the rebuilt head assembly according to "REASSEMBLY AFTER INSPECTION" above.

page 15
SEAL/DISC KIT:
For 3-inch through 8-inch valves, the Seal/Disc Repair Kit consists of two (2) Inner Bushing O-rings (418), two (2)
Bonnet O-rings (429), and one (1) Bonnet Gasket (412), one (1) Disc (413), one (1) Disc Bushing (403), one (1) Disc Washer
(402), one Disc Lock Washer (423)*, and one (1) Disc Nut (401).
Note: When ordering, specify whether your valve is resilient seated or metal seated. For 10-inch and 12-inch valves,
two (2) Bonnet O-rings (429). Two (2) Hinge Connectors (430), two (2) Retaining Washers (431) and two (2) Shaft Spacers
(432) are also required for assembly. (See gure 7) No Disc Bushing is required for the Disc Assembly.
1. Remove the head assembly as described under "DISASSEMBLY FOR INSPECTION" above.
2. Remove the bushings. For valves with a lever, one bushing is open (417) and one bushing is closed (422).
For valves without a lever, both bushings are closed (422).
3. Remove the old O-rings from each bushing and replace with new O-rings.
a. Valve sizes 3-inch through 8-inch, without a lever, have Bonnet O-rings (429) only.
b. Valve sizes 10-inch and 12-inch without a lever have two two (2) Bonnet O-rings (429).
c. Valve sizes 10-inch and 12-inch, equipped with a lever, have two (2) Inner Bushing
O-rings(418), and two (2) Bonnet O-rings (429).
d. 3-inch through 8-inch valves equipped with a lever, have two (2) Inner Bushing O-rings
(418) located inside the Open Bushing (417) and two (2) Bonnet O-rings (429).
4. Slide the Shaft-Hinge-Disc assembly from the bonnet (407).
5. Remove the Disc Nut (401) , Disc Bushing (403) Disc Washer (402), and Disc Lock Washer (423)* to
remove Disc (413) from Hinge (404).
NOTE: On 10-inch and 12-inch valves, a tab on the Disc Lock Washer must be bent to remove the lock
washer. ( See gure 7 )
6. Reassemble the Shaft-Hinge-Disc assembly as shown in gure (9). Tighten Disc Nut (401) until the Disc
Lock Washer (423) is at. On 10-inch and 12-inch valves, bend the appropriate tab on the Disc Lock
Washer to secure the Disc Nut.
NOTE: On 3-inch through 8-inch valves, insure that the thrust plate on the Disc (413) is located at the 6
o-clock position. ( See Detail "A", gure 10 ). On 10-inch and 12-inch valves, the Disc can only be mounted
as shown in gure (7).
7. Insert the rebuilt Shaft-Hinge-Disc assembly into the valve bonnet (407). Ensure the disc is facing the
proper direction. Refer to gure (7) for proper positioning of 10-inch and 12-inch valve components.
8. Install the new O-rings as shown in gures (7 or 9). Installing the Inner Bushing O-rings can best be
accomplished with a good set of small picks. Be careful not to cut the O-rings during installation.
9. Install the bushings in the valve bonnet (407) and tighten to 45-ft-lbs.
10. Install the rebuilt head assembly according to "REASSEMBLY AFTER INSPECTION" above.
* As of March 1st, 2008 on 3" through 8" valves, the Disc Lock Washer (423), and Disc Nut (401), are replaced by a new
self locking Disc Nut (401).

page 16
PARTS AND SERVICE
For information on parts and service for your area contact American AVK. Make a note of the valve model number and size
located on the valve and contact:
American AVK Company
2155 N. Meridian Blvd
Minden, NV 89423
PH: 775-552-1400
FAX: [phone]
www.americanavk.com
AMERICAN AVK COMPANY WARRANTY
SERIES 41/45-41/50 CHECK VALVES
American AVK Company warrants its Series 41/45 and 41/50 Check Valves to be free from defects in workmanship and
materials for a period of one (1) year from the date of shipment from American AVK Company. American AVK Company shall
have no obligation under this warranty unless it is notied of claims hereunder promptly and in writing upon discovery thereof
and within the warranty period, and unless the product is delivered to American AVK Company within thirty (30) days of such
notice.
American AVK shall have the right to inspect said product before it is removed from installation. If the product is removed from
installation prior to approval from American AVK this warranty shall be void. As to motors, gearing or accessory equipment
purchased by American AVK Company from other manufacturers, and used or incorporated into American AVK Company’s
products, those manufacturers’ warranties shall apply.
American AVK Company's sole responsibility shall be, in its sole discretion, to replace the product with the same or a similar
product, repair the product, or refund the price paid for the product provided the product has been properly applied and used
under normal service and under conditions for which it is designed.
American AVK Company shall not be liable for indirect, special, incidental, or consequential damage or penalties and does not
assume any liability of purchase to others or to anyone for injury to persons or property.
THIS IS THE EXCLUSIVE WARRANTY GIVEN IN CONNECTION WITH THE SALE OF THIS PRODUCT. THERE ARE
NO OTHER WARRANTIES, EXPRESSED OR IMPLIED, INCLUDING EXPRESSED OR IMPLIED WARRANTY OF
MERCHANTABILITY, OR ANY EXPRESSED OR IMPLIED WARRANTY OF SUITABILITY FOR ANY PARTICULAR
PURPOSE, GIVEN BY AMERICAN AVK COMPANY IN CONNECTION WITH THIS PRODUCT.

page 17
NOTES: