Dembla 7500 Series User manual

0062
2 G/D T 3/4/5/6
1Feb 2009
Instruction Manual
Manual Butterfly Valves
Series 7500

CONTENTS PAGE NO.
1.0 Foreword 2
1.1 Introduction 2
1.2 Scope of Instruction Manual 2
1.3 Copyrights and Modification Rights Reservation 2
2.0 Storage & Preservation 2
3.0 Valve Marking 3
4.0 Health & Safety 4
5.0 Unpacking 5
6.0 Lifting Details 6
7.0 Installation of Butterfly Valve 8
7.1 Pre-Installation Checks 8
7.2 Operation 8
7.3 Lubrication 8
8.0 Maintenance 9
9.0 Replacing Gland Packing 9
9.1 V-PTFE Packing 10
9.2 Double V-PTFE Packing 10
9.3 Grafoil Packing 11
9.4 Double Grafoil Packing 11
9.5 V-PTFE Low Fugitive Emission Packing 12
9.6 Grafoil Low Fugitive Emission Packing 12
10.0 Replacing Soft Seat 13
10.1 Replacing Guide Bush (Bearings) 14
10.2 Trouble Shooting 15
11.0 Hand Lever Type Manual Operator 15
11.1 Operation 16
11.2 Removing Hand Lever Operator from the Valve Body 16
12.0 Gear Box Type Manual Operator 17
12.1 Operation 17
12.2 Setting of Gear Box Type Operator 18
13.0 Installation of Manual Operator 19
13.1 Fixing / Mounting Hand Lever on Body Set 19
13.2 Fixing / Mounting Gear Box Type operator on Body Set 19
14.0 Parts Illustrated 20
14.1 Butterfly Valve Assembly Flange: - Size 2” (50mm) to 6” (150mm) 20
14.2 Butterfly Valve Assembly Flange: - Size 8” (200mm) & 72” (1800mm) 21
15.0 Torque for Studs 22
16.0 Recommended Spare Parts 22
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1

1.0 Foreword
1.1 Introduction
Dembla's High Performance Butterfly Valves are available in Wafer and Lug type designs conforming to API
609 standard. The Disc construction is Double Offset. Shafts are guided by bearings. Various seat options
are available.
1.2 Scope of Instruction Manual
This Instruction Manual covers information regarding Installation and Maintenance of Dembla's double
offset High Performance Butterfly Valves, Series 7500, Valve sizes 3” (DN50) to 72” (DN1800)
1.3 Copyrights and Modification Rights Reservation
Dembla Valves Ltd. retains the Copyright on the contents of this Instruction Manual.
The Total content of this Instruction Manual described here corresponds to the information
during preparation of the instruction manual. It is user's responsibility to refer the latest version.
All data, specifications and Illustrations here are subjected to Technical Modifications and
improvements and hence Modification can be done by us at any time without any prior notice.
No claim to Modification or repair of these Valves, which have already been supplied by us, can
be made.
2.0 Storage & Preservation
All Valves are dispatched in the closed/open position as ordered and it is recommended that they are left
in this position during storage. All protective packing should remain in position until the Valve is to be
installed. Valve should be stored in a clean and dry environment, without disturbing company setting. (e.g.
gland, seat etc.) Protect it from shock & lifting damage.
If hoisting the Valve, use a nylon sling to protect the surface. Carefully position the sling to prevent damage
to Actuator tubing and any accessory. Also, take care to prevent people from being injured in case the hoist
or rigging slips unexpectedly. For Valve Weight refer Valve Packing Slip.
2
!Caution

3.0 Valve Marking
1) Valve name plate attached on Valve by riveting carrying all Valve Identification Information.
2) Markings like Valve Size, Rating, Material etc. are as cast on Valve Bodies.
3) Valve serial no. punched on Valve Body Flange for Valve Traceability.
4) If the product is not CE marked, Then name plate also without CE mark.

Name plate for
Series:-7500 Valves
INDIA
0062 II 2 G/D T *
3

4.0 Health & Safety
1) Before attending to Valve Installation / Maintenance, the Instruction Manual must be compulsorily read
and understood properly.
2) Valve must be operated by qualified personnel.
3) Ensure that the operator handling these Valves must follow Safety and Accident Prevention Rules and
Regulations.
4) Follow the Safety Instructions before Installation, Maintenance or removing the Valve.
5) Always wear protective gloves, clothing and eyewear when performing any installation operations to avoid
personal injury.
6) All Safety Messages such as Cautions, Warnings and Notes are highlighted in this Instruction Manual
which must be strictly followed to avoid any possibility of arising danger / risk of damage to the
equipment / person's life
7) No Liability on Manufacturer for any wrong handling, improper commissioning and wrong assembly.
8) Line must be fully drained and de-pressurized before installation or maintenance of Valve.
9) Never handle Valves that have been used on harmful substances unless they have been completely
decontaminated and certified safe to handle.
10) Due to the large physical Size and Weight of some Size of this product, always use correct lifting methods
and equipment when installing , removing and maintaining the product:
Use lifting lugs on the Body, wherever provided.
Valve without lifting lugs-use chains or slings wrapped around the Body.
Do not attempt to lift the Valve using the Sealant Fittings, Gear Unit, Handwheel, Actuator, or the Valve Stem.
11) If the processes or environments that the products are used in are likely to cause temperature (high or low)
that may cause injury to person if touched, then adequate insulation / protection must be fitted.
It is recommended that the insulation allows easy access for maintenance, to the Sealant Fittings, and to
the Valve operator.
12) Valve must be protected from earthquake loading, traffic & wind.
13) No Modification / Conversions are allowed without written authorization from Dembla Valves Ltd.
Rise in temperature on surface of Valve Body depend on working media. End user must be
maintaining the surface temperature & it should not go beyond marking temperature on Valve (Name Plate).
!Warning
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4

5.0 Unpacking
For Carton
· Keep Carton in position (Carton ‘up side’ should not be ‘down’).
· Cut plastic strip properly which is tied around Carton & remove it. (White in colour).
· Cut cello tape properly which is stuck on Carton opening.
· Open Carton properly.
· Remove foam properly along with polythene wrapping.
· Lift the Valve properly & keep on clean & dry place
For Wooden Box
· Keep Wooden Box in Position (’upside’ of Wooden Box should not be’ down’).
· Cut iron strip properly which is tied around Wooden Box & remove it.
· Remove nail properly from top cover with proper equipment.
· Loosen and remove Valve fixing Nut (from inside of Box).
· Lift the Valve properly as shown in figure 1
6.0 Lifting Details
Valve should be lifted by using chain or bearer cables as shown in figure 1. (Take care that
Valve should not damage while handing).
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Fig .1
5

· Always wear protective gloves, clothing, and eye ware when performing any Installation operation to avoid
personal injury.
· Valve should be used by End-user with same pressure & temperature rating which was given in
Valve Marking (Name Plate) If there is any change please contact Dembla Sales Office.
· Avoid personal injury or property damage caused by components dropping .With the Valve or
actuator upside, components may drop during disassembly or assembly. Be careful not to position yourself
below the Valve in the path of falling parts.
· Personal injury could result from Packing Leakage. Valve Packing was tightened prior to shipment, but should
there be any Gland Leakage after Installation, further tightening, just enough to stop Gland Leak is required.
Excessive tightening will disturb Valve Calibration.
· Earthing facility must be provided by the end user before operating the Valve.
· Equipment should not be used for dead end service
After the Valve has been Installed, make a final check of the following :-
1) An occasional cleaning of Valve Stem will prevent dirt or grit being carried away into the Packing.
2) Vary air lines and fitting to the Actuator to ascertain Actual Travel Scale Indication.
3) Check all air lines and fitting to the Valve Actuator & Accessories for air leaks.
4) Ensure that the combined action of Controller, Positioner and Valve provide the desired Valve
Stem Movement. Also ensure the required fail safe position of Control Valve.
· In case of leak, presence of high temperature may be dangerous to the person’s life.
· Equipment to be used as per intended and not misused / improperly used to avoid dangerous effects
such as over load ,over heating ,stress corrosion cracking, etc.
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!Caution
6

7.0 Installation of Butterfly Valve
7.1 Pre-Installation Checks: (Before installing any Butterfly Valve)
(1) Inspect it for any shipment damage and for foreign material that might have collected during Packing and
shipment.
(2) Blow out all pipelines to remove pipe scale-chips, welding-slag, and other foreign materials.
(3) Install the Valve using accepted piping practices.
(4) Install the Valve according to flow direction marked on the Valve.
(5) Use self centering Gasket.
(6) Install the Control Valve preferably in a straight run of pipe away from bends or sections of abnormal velocity.
(7) Incorrect pipe alignment will cause interference between the disc edge and line flange face, excessive
torque and damage to disc and seat, resulting into Seat Leakage.
(8) Do not try to install Valve between line Flanges having inadequate gap. This may cause damage to some
Valve parts. If Valve is in fully open position, it will impact the flanges and damage the disc edge.
(9) Butterfly Valve should be attempted to install when disc in open condition. The Butterfly Valve can be
inserted between line Flanges in fully close position.
(10) Glands are factory tightened and checked for Leakage however if there is any Gland Leak in Valves, the
Gland may be further tightened just enough to stop Leakage. Excessive tightening should be avoided
(11) Before installing the Valve, make sure that pipeline flow is in the same direction as the arrow on the side
of the Valve.
(12) Connect the Valve in pipe line with standard connections.
(13) Valve should not be used for dead end service.
7.2 Operation
Valve closes with clockwise rotation of the Valve Shaft. Valve is fully closed when disc is parallel to Seat
Ring. The limit positions are set in the operators for extreme conditions i.e. open and closed.
7.3 Lubrication
The Valve Body set does not require any routine lubrication. However valve operator may require
lubrication which is to be referred in the Part-II Manual Operator Section of this Instruction Manual.
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7

15.0 Torque For Studs
16.0 Recommended Spare Parts
It is recommended to stock following spare parts for commissioning and routine service:
While Ordering Spares, Please do not miss to indicate 'Valve Serial No.' appearing on Nameplate
provided on the operator Yoke or on Valve Body Flange. The Valve Serial No. begins with alphabet 'V'
followed by numbers, for e.g. V-12345….
The contents of this publication are presented for informational purposes only, and while every effort has been
made to ensure their accuracy. They are not to be construed as warranties or guarantees, express or implied,
regarding the products or services described herein or their use or applicability. We reserve the right to modify or
improve the designs or specifications of such products at any time without notice.
Dembla does not assume responsibility for the selection, use or maintenance of any product. Responsibility
for proper selection, use and maintenance of any Dembla product remains solely with the purchaser and end-user.

Studs
5/16”
3/8”
1/2”
5/8”
3/4”
Torque Nm
5
7
30
50
170
PART NAME
Soft Seat
Guide Bush
Gland Packing
RECOMMENDED QUANTITY
One for every Five identical or One minimum.
One set for every Five identical or One set minimum.
(front & rear)
One Set for every Two identical or One Set minimum.
No.
3
9
12
8

Procedure for Disassembly & Assembly
Disc Seat Ring ( Soft Seat & Metal Seat)
Series :- 7500
DISASSEMBLY PROCEDURE
1. Clamp Valve Properly.
0
2. Rotate disc 90
3. Mark on disc retainer and disc of
the maintaining the proper position.
4. Loosen & remove body seat bolts.
5. Remove body seat along with 'O' ring.
6. Loosen & remove the disc retainer bolts.
7. Remove disc seat retainer along with
'O' ring.
8. Remove seat ring metal & soft from disc.
9. Loosen & remove gland flange bolt.
10. Remove Gland flange.
11. Remove gland packing.
12. Loosen & remove disc pin from
disc (Upper side 2 Nos.)
13. Loosen & remove disc pin from
disc (Bottom side 1 No.)
14. Loosen bottom cover bolt.
15. Remove bottom cover along
with gasket.
16. Clamp disc properly for top side
on valve body.
17. Pull & remove valve shaft from
bottom side of valve body.
18. Remove disc from body.
19. Loose & remove thrust washer bolts from thrust washer (if required)
20. Remove thrust washer from valve shaft (if required).
21. Pull & remove guide bush from valve body (if required).
7
4 7
1
2
3
4
9
10
8
15
15
14
17 18
16
5 6
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9

ASSEMBLY PROCEDURE
1. Insert guide bush on the valve body 2 Nos.
as show in Fig.1 (if removed).
2. Place the thrust washer on valve shaft from bottom
side & bolt it properly.
3. Insert the disc in the body & maintain it position.
4. Insert valve shaft (Bottom) in the valve body from
bottom side along with thrust washer.
5. Make sure valve shaft properly inserted in the disc also.
6. Insert the valve shaft (top) in the body from top side.
7. Make sure valve shaft properly inserted in the disc also.
8. Insert the disc pins in the disc throughout shaft for the
bottom & top bolt & tighten properly.
9. Insert the bottom cover in the body along with gasket.
10. Insert the bottom cover bolts in the bottom cover
& tighten it.
11. Insert the gland packing set in the valve body from
the top side as shown in fig.(Gland packing set consist
1 lower spreader,4 nos. v-ring, 1 no. upper spreader)
12. Insert the gland flange in the valve body from top side.
13. Insert the gland bolts in the gland flange & tighten it.
14. Insert the seat ring metal & soft in the disc.
15. Please refer fig.1 to maintain the position & sequence.
16. Insert disc retainer in the disc along with 'O' ring & maintain the position as
mark.
17. Insert & tighten the bolts in disc retainer.
o
18. Rotate the disc 90 .
19. Insert the body set retainer in the body along with 'O' ring.
20. Insert the bolts in the body set & tighten it.
21. It found any difficulties in closing or opening of disc. Loosen the disc retainer
bolts & retighten it properly.
19
17
16
18
15
14
13 14
8
10
9
5 6
7
3
2
1

10
Procedure for Disassembly & Assembly
Disc Seat Ring ( Soft Seat & Metal Seat)
Series :- 7500

Dembla
Sales Office: Works:
M/S. Dembla Valves Ltd.
C-30, Jai Matadi Compound, Kalher
Village,Thane-Bhiwandi-Agra Raod -
421302,
Maharashtra,India.
Tel - [phone] - 97
E-mail - [email protected]
More info - www.dembla.com
M/S. Dembla Valves Ltd.
A/8, Arahm Logistic, Valshind Village,
Mumbai -Nashik Highway
(NH3),Bhiwandi
Thane - 421302. Maharashtra (India)
Dembla Valves |
Note- Valve Disposal Detail - After the complete use of valve . Dispose the valve
with accessaries as per your local law.
The contents of this publication are presented for informational purposes only, and while every effort has been
made to ensure their accuracy. They are not to be construed as warranties or guarantees, express or implied,
regarding the products or services described herein or their use or applicability. We reserve the right to modify or
improve the designs or specifications of such products at any time without notice.
Dembla does not assume responsibility for the selection, use or maintenance of any product. Responsibility
for proper selection, use and maintenance of any Dembla product remains solely with the purchaser and end-user.