AVK 41 Series Troubleshooting guide

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COPYRIGHT©AVK GROUP A/S 2018
The designs, materials and specifications shown are subject to change without notice due to our continuing programme of product development.
O&M 020818
OPERATION AND MAINTENANCE INSTRUCTIONS
AVK SERIES 41 SWING CHECK VALVE FOR WATER AND WASTE
WATER
Series 41 DN350-600
1. INTRODUCTION
AVK Valves Swing Check Valves are primarily designed and manufactured for the prevention of flow reversal and
are suitable for potable water or sewage applications. The operation of the valve is fully automatic allowing liquid
to flow in one direction only. The function of the external lever and weight, where fitted, is to provide additional
weight loading to the valve disk, thus giving mechanical assistance towards closure. The position of the weight is
adjustable and allows the closure rate to be varied to suit the actual working conditions.
Swing check valve options covered by this manual
• Standard (without lever and weight)
• Lever and weight (right hand as standard)
• Lever, weight and guard
AVK GROUP A/S
An ISO 9001-2000 registered company
Maintenance Manual Series 41
*Subject to change without notice. (rev. 11/09 C)
AVK SERIES 41 SWING CHECK VALVE
FIELD MAINTENANCE AND INSTRUCTION
MANUAL FOR SWING CHECK VALVES DN350 - DN600
TABLE OF CONTENTS
EXPLODED ASSEMBLY / PARTS LIST
INTRODUCTION / DESCRIPTION
HEALTH AND SAFETY AT WORK
SPARE PARTS
DESIGN CONSTRAINTS
STORAGE AND HANDLING
INSTALLATION
- SWING
- LEVER AND WEIGHT
- LEVER, WEIGHT AND GUARD
MAINTENANCE
TROUBLESHOOTING
DISASSEMBLY FOR INSPECTION
RE-ASSEMBLY AFTER INSPECTION
AVK GROUP A/S

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COPYRIGHT©AVK GROUP A/S 2018
The designs, materials and specifications shown are subject to change without notice due to our continuing programme of product development.
O&M 020818
OPERATION AND MAINTENANCE INSTRUCTIONS
AVK SERIES 41 SWING CHECK VALVE FOR WATER AND WASTE WATER
Series 41 DN350-600
2. DN350-600 SERIES 41 SWINGCHECK VALVE EXPLODED VIEW
No Description
1 Closed Bushing
2 O-ring
3 O-ring
4 Spacer
5 Hinge Stem
6 O-cord
7 Bonnet
8 Studbolt
9 Washer
10 Nut
11 Eyebolt
12 Open Bushing
13 O-ring
14 Lever
15 Washer
page 1
AVK Series 41 Swingcheck Valve
Exploded Parts Breakdown
DN350 through DN600
12345 78
910 11 12 13 14 16
18
17
19
21
22
20
23
24
6
32 3031 29 28 252627
15
WASHER
ITEM
NO.
DESCRIPTION
1 CLOSED BUSHING
2 O-RING
3 O-RING
4 SPACER
5 HINGE STEM
6 O-CORD
7 BONNET
8 STUDBOLT
9 WASHER
10 NUT
11 EYEBOLT
12 OPEN BUSHING
13 O RING
14 LEVER
15
16
BOLT
17 WEIGHT
18 CAPSCREW
19 HINGE ARM
20 DISC
21 CONNECTOR
22 CAPSCREW
23 DISC SEAT RING
24 BODY SEAT RING
25 BUSH
26
BOLT
27 WASHER
28 BUSH
29
CAPSCREW
30 TAB WASHER
31 WASHER
32 BODY
No Description
16 Bolt
17 Weight
18 Capscrew
19 Hinge Arm
20 Disc
21 Connector
22 Capscrew
23 Disc Seat Ring
24 Body Seat Ring
25 Bush
26 Bolt
27 Washer
28 Bush
29 Capscrew
30 Tab Washer
No Description
31 Washer
32 Body

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AVK UK, 8 Rushmills, Northampton, England, UK, NN4 7YB, T: + 44 (0) 1604 601188. [email protected] www.avkuk.co.uk
COPYRIGHT©AVK GROUP A/S 2018
The designs, materials and specifications shown are subject to change without notice due to our continuing programme of product development.
O&M 020818
OPERATION AND MAINTENANCE INSTRUCTIONS
AVK SERIES 41 SWING CHECK VALVE FOR WATER AND WASTE WATER
Series 41 DN350-600
3. TABLE OF CONTENTS
• Introduction / description
• Exploded assembly / parts list
• Table of contents
• Health and safety at work
• Spare parts
• Design constraints
• Storage and handling
• Installation
- Swing
- Lever and weight
- Lever, weight and guard
• Maintenance
• Troubleshooting
• Disassembly for inspection
• Re-assembly after inspection
PAGES
1
2
3
4
5
5
5
6 - 8
9
9
10
10

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COPYRIGHT©AVK GROUP A/S 2018
The designs, materials and specifications shown are subject to change without notice due to our continuing programme of product development.
O&M 020818
4. HEALTH AND SAFETY PRECAUTIONS
Please ensure that all relevant Health and Safety issues and regulations are strictly adhered to, prior to and during any
installation or maintenance work carried out on these valves.
It is essential that wherever work is being undertaken on a valve that may involve the release of any internal pressure, the
valve is fully depressurised prior to any work being carried out, and the line drained.
It is also essential that the user handling the valve is aware of the weight of the components or assemblies to be handled and
manipulated during installation and maintenance. It is the end users responsibility to ensure that safe working practices are
followed at all times.
Whenever AVK Valves products are installed, operated, or maintained, the inherent dangers of pressurised liquids and gasses,
which can be severe, must be addressed.
Therefore, it is essential that staff undertaking these operations are adequately trained and it is the responsibility of the end user to
ensure that only trained and competent staff undertake these duties.
This manual has been designed to assist, but it can never fully replace quality training in the workplace. However AVK Valves
technical staff are always available to answer any questions relating to specific problems that may not be covered by this manual.
AVK Valves products are designed and manufactured to be for purpose, and to a high and reliable standard. This provides a safe
product with minimum risk to health when used correctly for the purpose for which it was designed.
However, this assumes that the equipment is used and maintained in accordance with this manual, and the user is advised to
study this manual, and to make it available to all staff that may need to refer to it.
AVK Valves cannot be held responsible for any incidents arising from incorrect installation, operation or maintenance. The
responsibility for this must rest wholly with the end user.
Note: These valves are NOT designed for “end of line” services.
5. SPARE PARTS
The use of inferior materials or parts in a valve can have serious consequences. Therefore it is absolutely essential that in order to
guarantee the highest level of safety and performance, only genuine AVK Valves spare parts are be used.
AVK Valves cannot accept any responsibility whatsoever for the fitting and subsequent failure of any non-AVK Valves or non-
approved parts.
6. DESIGN CONSTRAINTS
Please consider the following points when selecting your valve:
• Consideration should be given at the design stage where valves will be located to give access for operation, adjustment,
maintenance and repair.
• If a valve is installed less than 6 diameters downstream of an elbow or tee etc., it will experience very high-localised velocities
that are far in excess of the average velocity. This high velocity will result in excessive turbulence within the valve and
variations in performance may be experienced, therefore installation in this area should be avoided.
• Valves must be provided with adequate support. Adjoining pipework must be supported to avoid the imposition of pipeline
strains on the body which may impair its performance
• Heavy Valves may need independent support or anchorage
7. STORAGE AND HANDLING
Storage
• If valves are to be stored in the open for some time, protection should be provided to keep the valve clear of sand and mud
• Protection against weather should be provided. Ideally, valves should be kept indoors, with the actual valve temperature
always higher than the dew point. If outdoor storage is unavoidable, valve should be supported off the ground and protected
by a weather proof cover
• Valves may be stacked and the upper open end covered with waterproof material and boarded over
Handling
• When handling valves, it is preferable to lift by means of shackles in the holes provided in the valve body/cover
• Where slings are employed the valves should only be slung by the main body casting. No contact should be made with the
lever or guard fitted
• Valves should be lowered gently onto wooden batten placed on firm ground, clear of mud and water.
OPERATION AND MAINTENANCE INSTRUCTIONS
AVK SERIES 41 SWING CHECK VALVE FOR WATER AND WASTE WATER
Series 41 DN350-600

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COPYRIGHT©AVK GROUP A/S 2018
The designs, materials and specifications shown are subject to change without notice due to our continuing programme of product development.
O&M 020818
OPERATION AND MAINTENANCE INSTRUCTIONS
AVK SERIES 41 SWING CHECK VALVE FOR WATER AND WASTE WATER
Series 41 DN350-600
8. INSTALLATION
Correct installation of the Series 41 check valve is important for proper operation. It may be installed in either horizontal or vertical
flow-up applications. If installed in the vertical flow-up position, a lever and weight or lever assembly must be used to ensure
proper valve operation. See figures 1, 2 and 3 for proper positioning of the lever and weight for horizontal and vertical flow-up
applications. In all installations, the flow arrow cast on the valve body must be pointed in the direction of flow during normal
system operation.
Flanged valves should be mated with raised-faced pope flanges equipped with full face resilient gaskets. Once the flange bolts or
studs are lubricated and inserted around the flange, 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 should be used.
Direction of Flow
Front View
Top View
Fig.1
Horizontal Mountin
g
page 4
Direction of Flow
Front View
Top View
Fig.1
Horizontal Mountin
g
page 4
Side View

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AVK UK, 8 Rushmills, Northampton, England, UK, NN4 7YB, T: + 44 (0) 1604 601188. [email protected] www.avkuk.co.uk
COPYRIGHT©AVK GROUP A/S 2018
The designs, materials and specifications shown are subject to change without notice due to our continuing programme of product development.
O&M 020818
OPERATION AND MAINTENANCE INSTRUCTIONS
AVK SERIES 41 SWING CHECK VALVE FOR WATER AND WASTE WATER
Series 41 DN350-600
page 5
Direction
of
Flow
Front View Rear View
Fig.2
Vertical Mounting
Side View Side View

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COPYRIGHT©AVK GROUP A/S 2018
The designs, materials and specifications shown are subject to change without notice due to our continuing programme of product development.
O&M 020818
OPERATION AND MAINTENANCE INSTRUCTIONS
AVK SERIES 41 SWING CHECK VALVE FOR WATER AND WASTE WATER
Series 41 DN350-600
SDJH
Open Position
Closed Position
Open Position
Closed Position
Vertical Mounting
Direction of Flow
Direction
of
Flow
Horizontal Mounting
Fig.3
Optimal Leverage
Configurations

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COPYRIGHT©AVK GROUP A/S 2018
The designs, materials and specifications shown are subject to change without notice due to our continuing programme of product development.
O&M 020818
9. INSTALLATION - continued
Swing
A valve without 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 Hinge stem passing through
the open bushing in the bonnet. Slide the lever onto the hinge stem and position as shown in figure 2. Secure the lever with the
washer and nut and tighten. Attach the weight and tighten the capscrew to hold the weight in place. A medium strength thread
locking compound such as Loctite 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 in operation. Serious injury can occur.
OPERATION AND MAINTENANCE INSTRUCTIONS
AVK SERIES 41 SWING CHECK VALVE FOR WATER AND WASTE WATER
Series 41 DN350-600
page 7
Direction
of
Flow
INSTALLATION - continued:
SWING
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LEVER AND WEIGHT (OPTIONAL)
Once the valve is properly installed, the lever and weight assembly needs to be attached to the Hinge stem passing
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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 in operation. Serious injury can occur.
Fig. 4
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COPYRIGHT©AVK GROUP A/S 2018
The designs, materials and specifications shown are subject to change without notice due to our continuing programme of product development.
O&M 020818
10. MAINTENANCE AND INSPECTION
All AVK swing check valves are automatic in operation allowing flow in one direction only
MAINTENANCE:
The valve is designed for underground use with little maintenance and no lubrication required. However, attention to the
following points will ensure satisfactory working at all times.
Removing the head assembly from the valve and examining the faces and moving parts for wear and if necessary, removing the
hinge stem, and lifting out the internal for more detailed examination or re-conditioning. New parts can be fitted as required.
The frequency of the maintenance depends not on the length of time that valve has been installed, but on the flow conditions,
If the flow is such that the door is held stationary against the open stop, the valve should operate for some years without
attention.
However, fluctuating flow or low flow causing constant movement of the door and linkage, can result in hinge stem wear. The
need for servicing due to wear and tear is indicated by mechanical noise and/ or failure of the valve to prevent back flow. It is
usually advisable to renew joints after disturbing them.
Maintenance Schedule
1. Valves that are not operated frequently and which may remain open or closed for long periods should be operated, even
partially, about once a month.
2. Inspection - Should be carried out thoroughly every six months. If inspection of the valve is required, follow the
DISASSEMBLY FOR INSPECTION Instructions.
3. O-rings and O-cord - When faulty O-rings and O-cord are the cause of leaks, care should be taken to ensure that the
replacements are of the correct material.
4. Vibration - After lengthy periods of operation connecting bolts should be checked for tightness. (This should be done more
often if vibration is experienced in the pipeline).
5. Freezing - Where it is necessary to keep a valve closed in cold weather precautions must be taken to prevent it ‘freezing
up’.
6. Scouring - Routine scouring is of great value in keeping the water free of grit and thus saving unnecessary wear and tear
on the faces and seals.
11. TROUBLESHOOTING
Several problems and solutions are presented below to assist you in troubleshooting the valve.
Leakage at the shaft bushing (Open bushing, closed bushing): Ensure that the shaft bushings are properly tightened. If leakage
persists replace the inner and outer bushing o-rings.
Leakage at the bonnet: Ensure that the bonnet bolts are tightened. If leakage persists, replace bonnet o-cord.
Valve leaks when closed: remove and inspect the disc for damage. Replace is necessary. Ensure that the sealing surface in the
valve body is clean and undamaged.
Valve does not close or open: Verify operating pressure is high enough to open the valve. Disassemble the valve to check for an
obstruction in the valve or pipeline.
OPERATION AND MAINTENANCE INSTRUCTIONS
AVK SERIES 41 SWING CHECK VALVE FOR WATER AND WASTE WATER
Series 41 DN350-600

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COPYRIGHT©AVK GROUP A/S 2018
The designs, materials and specifications shown are subject to change without notice due to our continuing programme of product development.
O&M 020818
12. 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 (6). If equipped with a lever and weight, the weights may need to be removed from the lever before the head
assembly can be removed. If equipped with a lever, weight and guard, the front part guard may need to be removed from the
back part guard first then remove the weights from the lever before the head assemble can be removed. Remove the bonnet
bolts, and bonnet washers from the bonnet. Note: bolt length when the bolts are removed. The bonnet bolts are different
lengths depending on location (upstream or downstream) the longer bonnet bolts are located upstream.
2. Pry the bonnet loose and lift of the head assembly. Refer to figure (6) 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.
13. REASSEMBLY AFTER INSPECTION
All parts and sealing surfaces must be cleaned before reassembly. Worn parts and seals should bere placed prior to reassembly.
1. Lay the head assembly upside down on a clean surface so that the disc is up.
2. Place the studbolts in the valve body. Ensure that the studbolts are properly installed. Place the bonnet O-cord in the groove
in the Bonnet.
3. Pick up the head assembly holding bonnet O-cord in place and mount it on the valve body. The studbolts in the valve body
should carefully pass through the bolt holes in the bonnet. Ensure that the disc is facing the proper direction and that the
bonnet O-cord is not being pinched between the bonnet and valve body.
4. Place a washer and a nut on each of the studbolts. Tighten the nuts incrementally in a crossover pattern to ensure that the
bonnet does not bend and the bonnet O-cord is evenly compressed.
5. If equipped with a lever and weight assembly, remount weights if necessary. If equipped with a lever and weight and guard
assembly, remount weights if necessary and remount front part guard at last by tightening bolts and nuts around guard.
OPERATION AND MAINTENANCE INSTRUCTIONS
AVK SERIES 41 SWING CHECK VALVE FOR WATER AND WASTE WATER
Series 41 DN350-600
)LJ
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.
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before the head assembly can be removed. If equipped with a lever, weight and guard, the front part guard
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length when he bolts are removed. The bonnet bolts are different lengths depending on location
(upstream or downstream). The longer bonnet bolts are located upstream.
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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.
)LJ
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.
  5HIHUWR)LJXUH,IHTXLSSHGZLWKDOHYHUDQGZHLJKWWKHZHLJKWVPD\QHHGWREHUHPRYHGIURPWKHOHYHU
before the head assembly can be removed. If equipped with a lever, weight and guard, the front part guard
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  DVVHPEO\FDQEHUHPRYHG5HPRYHWKH%RQQHW%ROWVDQG%RQQHW:DVKHUVIURPWKH%RQQHW1RWHEROW 
length when he bolts are removed. The bonnet bolts are different lengths depending on location
(upstream or downstream). The longer bonnet bolts are located upstream.
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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.