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Stop valve with bellow seals
Model 248 | Installation and maintenance instructions
1. Safety information
The safe operation of these units can only be guaranteed if their installation and commissioning are properly performed and their maintenance is
carried out by a qualified person in accordance with the operating instructions. The general installation and safety instructions for the construction
of lines and plants must also be complied with and appropriate use must be made of the safety tools and equipment.
2. Product description
The range of PN16 and PN40 stop valves with a bellow with flanges is designed for use in steam, gas, liquid, condensate and water systems.
Bellow sealed globe valves are manufactured at different executions, they are used as stop valves and throttling valves. Stop valves are desig-
ned only for shut off and open the flow, throttling valves are designed for flow control. Stem sealing is performed by flexible bellow and additional
protecting gland.
Bellow sealed valves are provided with casted marking according to requirements of PN-EN19 standard. The marking facilitates technical iden-
tification and contains:
- Nominal diameter DN (mm),
- Nominal pressure PN (bar),
- Body and bonnet material marking,
- Arrow indicating medium flow direction,
- Manufacturer marking,
- Heat number,
- CE marking, for valves subjected 2014/68/UE directive.
3. Function
Valves with stop disc are designed for shut off medium flow, valves with throttling disc enable to control the flow.
The kind of working medium makes some materials to be use or to be prohibited for use. Valves were designed for normal working conditions. In
the case that working conditions exceed these requirements (for example for aggressive or abrasive medium) user should ask manufacturer be-
fore placing an order. When selecting the valve for specific medium, "List of Chemical Resistance" can be helpful. It can be found at manufacturer
website near catalogue cards.
Working pressure should be adapted to maximum medium temperature according to the table as below.
Acc. to EN 1092-2
Temperature [ºC]
Material
PN
-10 up to 120
150
200
5.3103
16
16,00 bar
15,50 bar
14,70 bar
Nodular iron
Acc. to EN 1092-1
Temperature [ºC]
From -60
-10 up to
Material
PN
100
150
200
up to -10
120
1.0619
40
30,00 bar
40,00 bar
37,10 bar
35,20 bar
33,30 bar
Carbon steel
¡Important! Valves made of cast steel 1.0619 working at temperatures above 400° C cannot operate for more than 100,000 hours because of the
creep of a material.
- Bellow stop valves play an important role in saving energy by eliminating leaks through the rod.
- The valve is activated manually by means of a handwheel. Make sure that the handwheel moves in the right direction. To fully open the valve, it is
advisable to turn the handwheel until the rod reaches the highest point, then turn the handwheel from 1/8 to 1/4 clockwise to prevent it from getting
stuck in an open position. You will thus avoid trying to open a valve which is fully open, causing damage to the rod, bellow or other components.
- If you use a wrench to open or close the valve, do not exert excessive force.
- The 248 model valves have a regulation cone to control the flow of the fluid. The flow will depend on the number of turns of the handwheel.
4. Maintenance
All the internal parts of a bellow stop valve can be replaced.
Before carrying out any maintenance on the valve, isolate the inlet and outlet and allow the pressure to level off to an atmospheric reading. Allow
to cool. Ensure that the joining faces are clean during the reassembly.
Gasket body/guide support
This can be done with the valve assembled on the line. Remove the guide support (9) from the body (1) by unscrewing the bolts or studs (10) /
nuts (11) from the guide support (9). The gasket body (8) is exposed and can be changed. The contact surfaces must be clean before assembling
the new gasket. To change the second gasket between the guide support (9) and the stainless steel bellow disc (7). Turn the handwheel (18) in a
clockwise direction. This will cause the rod (5) to go down, creating a space between the guide support (9) and the neck of the bellow disc (7). If
the neck of the support is still attached to the guide support (9), move it gently so as not to damage the neck. The bellow should not be stretched,
as this will reduce its useful life.
If the handwheel (18) continues to be turned clockwise, the rod (5) can be unscrewed from the guide (16). Once the rod has been disconnected
from the guide, unscrew the stuffing box. Now the rod/bellow set (5,6) can be removed from the guide support (9) and the second gasket (10) can
be changed, making sure that the contact surfaces are clean and that the gasket is properly positioned. Before reassembling the rod/bellow set
(5,6) on the guide support (9), the packing (12) must be replaced.
Packing
To replace the packing (12), follow the steps in the Gasket body/guide support section. Two units are supplied in each kit. Make sure that all the
remains of the old packing have been removed from the guide support and that the surfaces are clean. To assemble, proceed in reverse order,
remembering to assemble the gasket between the guide support and the neck of the bellow disc. Ensure that the rod pin is aligned with the groove
in the head. Place the new packing (12) and the stuffing box on the rod before screwing the end of the rod into the guide. Make sure that the rod's
thread does not damage the packing. Carefully insert the packing into the cavity. Remember to tighten the stuffing box once the valve has been
fully assembled.
Rod and bellow set
After following the steps in the Gasket body/guide support section, the new rod/bellow unit (5,6) can be assembled. To assemble proceed in
reverse order. Check that the gasket (8) between the guide support (9) and the neck of the bellow disc is properly assembled. Before assembling
the new rod/bellow set (5,6), apply a little lubricating grease to the end of the rod pin. Ensure that the rod pin is aligned with the groove in the guide
support. Carefully slide the rod through the guide support. Position a new packing (12) and the stuffing box before screwing the end of the rod (5)
into the guide (16). Ensure that the rod's thread does not damage the packing. Carefully insert the packing into the cavity. Remember to tighten
the stuffing box once the valve has been fully assembled.
Disc
After following the steps in the Gasket body/guide support section, the valve plug can be replaced. To change the plug (3) just remove the spring
pin and replace the plug (3). Assemble the new plug (3) with a new spring pin.
Handwheel
The handwheel (18) is not supplied as a spare part. But if you have to remove the handwheel, unscrew the nut holding the handwheel in a cloc-
kwise direction. Note: The thread of the wheel nut is on the left, so it must be unscrewed in a clockwise direction. Use a suitable wrench on the
planes of the guide support nuts (9) and unscrew the handwheel.
Final assembly
Ensure that the neck of the bellow disc (7) and the gaskets (8) are properly aligned with the head before the final assembly to the body (1) of the
valve. Sequentially tighten the bolts/studs (10) and nuts (11) to the recommended tightening torque.
5. Reasons of operating disturbances and remedy
Fault
250
300
350
No flow
13,9 bar
12,8 bar
11,2 bar
Poor flow
250
300
350
400
Control difficulties
30,40 bar
27,60 bar
25,70 bar
23,80 bar
Steam leakage
Seat lakage
Broken connection flange
6. Transport and storage
Figure 1
Transport and storage should be carried out at temperature from -20ºC to 65ºC, and valves should be protected against external forces influence
and destruction of painting layer as well. The aim of painting layer is to protect the valves against rust during transport and storage. Valves should
be kept at unpolluted rooms and they should be also protected against influence of atmospheric conditions. There should be applied drying agent
or heating at damp rooms in order to prevent condensate formation. The valves should be transported in such a way to avoid handwheel and
valve stem damage.
Possible reason
Remedy
Valve closed
Open the valve
Flange dust caps were not removed
Remove dust caps on the flanges
Valve is not open enough
Open the valve
Dirty filter
Clean or replace the screen
Clogged pipeline
Check the pipeline
Dry stem
Grease the stem
Slightly slacken gland nuts. Put attention to keep stuffing
Gland packing tighten too much
box tightness
Tighten the gland until tightness will be reached. Replace
Bellow damage
upper part of the valve as soon as possible.
Shut off not correct
Tighten the handwheels without any auxiliary tools
Seat or disc damage
Replace the valve and contact supplier or manufacturer
Apply valve with balancing disc. Check if the valve was
Too much pressure diference
assembled according to arrow direction marked on the
valve.
Medium polluted with solid particles
Clean the valve. Fit strainer before the valve.
Bolts tighten unevenly
Replace the valve with new one
7. Assembly
During the assembly of bellow valves following rules should be observed:
- To evaluate before an assembly if the valves were not damaged during the transport or storage and to make sure that applied valves are suitable
for working conditions and medium used in the plant.
- To take off dust caps if the valves are provided with them.
- To protect the valves during welding jobs against splinters and used plastics against excessive temperature.
- Steam pipelines should be fitted in such a way to avoid condensate collection; in order to avoid water hammer steam trap should be applied.
Important: The valve is shipped in closed position, with its maximum tightening torque, to avoid vibrations and shocks between seat and plug
during transport.
It is common that on first use the handwheel is too tight and cannot be unlocked by hand. In this case, proceed as follows:
1. Unscrew the plug (19) and remove the plate (21) and handwheel (18).
2. Unlock by turning the guide (16) counterclockwise using a spanner.
3. Replace the handwheel (18), plate (21) and screw in the plug (19).
Figure 1
Correct assembly
Figure 2
Nº PIECE
PIECE
1
Body
19
2
Seat
3
Plug
4
Pin
18
Figure 2
Rod
5
6
Bellow
Bellow disc
7
10
8
Gasket body
9
Guide support
10
Bolt/Screw
9
11
Nut
12
Packing
13
Stuffing box
14
Pin
1
15
Removable lock washer
16
Insert nut
17
Grease fitting
18
Handwheel
19
Cap
20
Shim ring
2
21
Plate
www.vycindustrial.com
Avenc del Daví, 22
Pol. Ind. Can Petit
08227 TERRASSA (Barcelona) SPAIN
+34 93 735 76 90
119
info@vycindustrial.com
Wrong assembly
20
1
3
21
17
16
14
11
15
13
5
4
2
12
12
Metric
Torque
7
8 8
M8
15-20 Nm
M10
35-40 Nm
6
M12
65-70 Nm
4
3
M16
140-150 Nm
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