Wey MF User manual

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WEY KNIFE GATE VALVE MF/MG/MH
Instruction manual
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weyvalve.ch | 2_30_12_en | Version 2016.07

WEY KNIFE GATE VALVE MF/MG/MH | Instruction manual
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1General
1.1 Safety
1.2 Designated service
1.3 Structure and function
1.4 Marking
2Transportation, Storage
2.1 Transportation
2.2 Storage
3Installation
3.1 Preparation before installation
3.2 Installation site
3.3Installation position
3.4 Flow and pressure direction
3.5 Mounting
4Commissioning
4.1 General measures
4.2 Safety measures
4.3 Function Test
4.4 Pneumatically operated valves
4.5 Hydraulically operated valves
4.6 Electrically actuated valves
5Maintenance
5.1 Inspection
5.2 Operating cycles
5.3 Repacking
5.4 Seal replacement
5.5 Cleaning / Lubrication
6Trouble Shooting
7Removal
8Disposal
9Final remarks

WEY KNIFE GATE VALVE MF/MG/MH | Instruction manual
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1General
1.1 Safety
Prior to any work or start-up and in order to ensure a proper functioning of our products, The instruction manual
must be observed. Alterations on the products need our written approval. For consequential damages due to
neglect of this direction, we have to reject any liability.
This symbol marks safety and risk advice. Follow all such advice in order to prevent any damage to human life
and objects.
The installation must be carried out according to established procedures and only by qualified personnel. Project
related data of valves, e.g. dimensions, materials and service range are found in the respective documentation.
The responsibility for the service application remains the sole duty of the end user.
1.2 Designated service
Wey Knife gate valves are deigned to shut-off pressurized piping systems. Depending of the construction,
finishing equipment and material valves can be used in fluid group 1 and 2 according to PED 2014/68/EU up to
category III. Wey Knife gate valves may be installed as end-of-line service, provided that the valves are classified
according to Art. 4 (3) PED 2014/68/EU. The max. working pressure must not exceed 0.73-times of the max.
nominal pressure at room temperature. In addition, the chapter 3.5 must be considered. For the valve design
working limitations refer to the relevant project data documentation and the maintenance manual. Should the
Wey Knife gate valve be installed in an explosion-protected area, the valve and the electrical and non-
electrical equipment must meet the explosion zone RL 2014/34/EU, ATEX
1.3 Structure and function
Figure 1: Structure
A
Body with seal
B
Gate
C
Manual actuation
D
Pneumatical actuation
E
Electrical actuation
F
Hydraulic actuation
A
B
C
D
E
F

WEY KNIFE GATE VALVE MF/MG/MH | Instruction manual
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1.4 Marking
Manufacturer Example
Type / Material
Size / Flange drilling
Year / Fabr. No.
Nominal pressure
Operating pressure
Medium temp.
Ambient temp.
Air supply pressure 1)
Conformity / No notified body 1)
1) if applicable
2Transportation, Storage
2.1 Transportation
Transportation of the valves to their final destination (building site) shall take place in solid crates adapted to the
valves’ size. The valves shall be protected against exterior damage and atmospheric exposure.
Depending on the duration of transportation or storage and in view of the conditions, preservation shall take
place by welding valves into PE-film or adding sufficient drying agent or equal.
2.2 Storage
Until final installation the valves shall be stored in a dry, vented area. All function relevant parts shall be suitably
covered against humidity, dust or other contamination.
For longer storage periods or in case of unfavourable storage conditions which might affect later functioning, all
blank surfaces, e.g. stem, piston rod, sealing surfaces shall be suitably protected by long-term preservatives
against corrosion.
Factory applied preservatives shall be checked for possible transport damages and appropriately repaired, if
necessary.
For accessories mounted to the valves, such as electric actuators, limit switches, solenoids, etc., the respective
storage instructions of the manufacturer shall be observed with priority.
3Installation
3.1 Preparation before installation
Before installation, please make sure that the subject Wey Knife gate valve is in conformance to the service
conditions. The responsibility regarding applied service medium (corrosion resistance, pressure, temperature etc.)
is with the end-user. Please check, if the valve to be installed in an explosion protected area, the valve meets the
rules for the relevant zone.
Not correctly aligned pipelines must, by all means, be corrected before installation in order to avoid tensions or
even cracking of the valve body. Before final installation of the valves, any possibly applied corrosion protec tion
shall be thoroughly removed. All parts, and in particular the gate, stem and piston rod shall be free of dust and
dirt.

WEY KNIFE GATE VALVE MF/MG/MH | Instruction manual
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3.2 Installation site
The mounting position must be chosen in such a way, that the knife gate valve can be checked and repaired at
any time without risks. For repacking purpose, the small side of the valve body shall be freely accessible (Fig. 2).
Figure 2: Installation site
= Repacking feature
Additional directives and guidelines for installation and operation of explosion protection equipment, when
installed into Ex-zones, must also be observed. Check if the equipment fulfils the safety requirements at site.
For outdoor installations, the valves shall be protected at site with shields or covers against severe weather
conditions like snow and ice.
3.3 Installation position
Wey Knife gate valves will be installed in one of the positions shown in Fig.3. Avoid a different installation
position whenever possible.
Figure 3: Installation position
Wey Knife gate valves from size DN400 up with extended or heavy actuators, which are not vertical installed,
should be supported on site. This is also recommended if vibrations of the piping line may occur.
200
200
200

WEY KNIFE GATE VALVE MF/MG/MH | Instruction manual
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3.4 Flow and pressure direction
The Wey Knife gate valve is a bi-directional design (Fig.4). Depending on applications and valve design options a
preferred flow direction must be considered.
Liquid, gaseous and pneumatic conveyed solid fluids
Flow direction
Bi-directional possible (A,B)
With the application of a wear ring from the entry side (B)
Pressure direction
Against gate bevel preferred (A)
Powder and granulate at gravity discharge
(vertical piping)
Flow direction
Pressure direction
The gate bevel is positioned on the descending side, also when a cone insert is used
(B)
The preferred pressure direction must especially be considered, if the valve is working at 60 – 100% of the
nominal pressure.
Figure 4: Pressure direction
1 Gate bevel shape
2 Wear ring (option)
3 Cone insert / contracted bore (option)
For difficult service conditions or for custom-made valves, please contact the manufacturer
regarding the installation position.
3.5 Mounting
Before mounting, check Wey Knife gate valves for possible transportation or storage damages.
The valves shall be protected against construction work at site.
For additional painting of the valves, the stem, piston rod, electric accessories and the valve gate protruding the
body shall not be painted. Before any sand blasting, the valves shall be protected with covers.
For valves with a stem extension, the pipeline flange must be exactly in line with the extension. The exact position
of the flange holes in relation to the extension shall also be observed.
1
2
B
A
B
1
3

WEY KNIFE GATE VALVE MF/MG/MH | Instruction manual
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Wey Knife gate valves are installed between two piping flanges with thru bolts and with bolts for body blind
holes.
Piping system misalignments must never be corrected using the valve body. Tighten bolts with caution, so that
tensions in the body do not cause any cracking or breaking. No tilting, steady crosswise tightening.
Bolt torques are to be observed. Table 1
POS. APOS. B POS. C
Figure 5: Mounting
POS. A
Wrong assembly. Tightened bolts shall not touch the bottom of the tapped blind holes.
POS. B
Correct assembly.
POS. C
Also correct assembly. Insert stud, then tighten nut.
Valves of the middle flange design have flanges with through holes.
Mounting acc. to fig. 6.
Mounting as head valve Mounting between flanges
Figure 6: Mounting Knife Gate Valve
Wey Knife gate valves MF, MG, MH are provide as wafer type valve and as end-of-line valve. The chapter 1.2
must be considered.
The dimensions of the flange bolts, its number are found in the documentation.
Table1 Torque for flange bolts

WEY KNIFE GATE VALVE MF/MG/MH | Instruction manual
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Based upon type of flange gasket, manufacturer's instructions are to be observed. It is
to ensure that the flange connection is tight. Leakage can be dangerous to humans
and environment.
The installation as an end or head valve requires special attention. In service, the downstream side must not be
accessible for persons. See also chapter 1.2 and 4.2.
For hazardous service media double transverse seals with respective leakage ports are incorporated and must be
compellingly connected to ensure a controlled drain-off of possible leak fluids.
After installation a correct earthing connection must be verified. This is normally done through the flange bolt
connection. If this is not the case, the potential or guard wire must be drawn to the terminal clamp.
Should there be a longer time period between mounting and power connection of electrically operated valves, it
shall be ensured that the integral heater of the actuator is already connected during mounting of the valves in
order to avoid the formation of condensate water (or protect actuator with suitable drying agent).
4Commissioning
4.1 General measures
Before taking the valves into service, all function relevant parts (gate, stem, piston rod, etc.) shall be thoroughly
cleaned. Damages, in particular to the seal caused by remains of grit, welding beads, foreign rust or similar on
the gate, are not covered by the warranty.
For powder or granular service, it should be observed that wetted or humid media which has tendency to cake to
the gate is thoroughly removed before start-up.
The Wey Knife gate valves are factory preserved and lubricated for transportation and storage, but they require
depending on the service conditions, another lubrication before start-up. Recommended are water-repellent,
temperature resistant and long lasting lubricants. (Get your nearest supplier’s recommendation).
4.2 Safety measures
For automated valves installed in an area where valve movement could be dangerous for people (or
animals/objects), it must be ensured by the user on-site that all moving parts are fenced with a suitable cover or
protection shield.
Should they not already be mounted, such covers are optionally available from manufacturer. Protection goals
can also be reached through suitable on-site measure. Unprotected valves must not be commissioned.
Bolt thread
[mm]
Torque
[Nm]
M16
60
M20
120
M24
220
M27
320
M30
440
M33
600
M36
770

WEY KNIFE GATE VALVE MF/MG/MH | Instruction manual
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If hot gases or fluids are transported in the pipeline, ensure that no persons can touch the hot surfaces.
It is also to ensure that no external interference of the control circuits can actuate the valve unintentionally.
4.3 Function Test
Before commissioning a function, test must be performed. Open and close the valve one time as a minimum.
If the pipeline is pressure tested, it is to ensure that the applied pressure is not higher than the maximum allowed
test pressure of the valve.
4.4 Pneumatically operated valves
Preventive measures must be taken, that the maximum tank pressure is not exceeding ( 8 bar), also not in a
breakdown situation.
For operation of the actuator use only dry, filtered air acc. Class 4/5 ISO 8573-1
max. dust particle size 40 µm
max. dust particle concentration 10 mg/m3
max. excess oil concentration 5 mg/m3
pressure dew-point below minimal ambient temperature
Solenoid valves shall be mounted as close as possible to the actuating cylinder.
Air hoses, especially plastic pipes must be mounted and secured so that they cannot be unintentionally
interrupted or torn. In order to keep a valve tight in its closed position, the piston must be permanently under
pressure.
The size of the air supply pipes has to be in relation to the air volume.
Before start-up, all on-site mounted supply pipes and solenoid valves shall be thoroughly flushed and cleaned, if
necessary.
Factory mounted solenoid valves are normally provided without accessories like throttle or muffler. On-site
regulations must therefore be observed.
Pneumatically operated valves shall not be closed instantly in order to avoid the risk of pressure shocks.
4.5 Hydraulically operated valves
Before start-up, all on-site mounted supply pipes shall be thoroughly cleaned. Hydraulically actuated valves
shall not be closed instantly in order to avoid the risk of pressure shocks.

WEY KNIFE GATE VALVE MF/MG/MH | Instruction manual
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The maximum design air-supply pressure must not exceed. Higher air-supply pressure may damage the Wey
Knife gate valve.
4.6 Electrically actuated valves
For electrical installations observe local rules, standards and directives. Additional directives and guidelines for
installation and operation of explosion protection equipment, when installed into Ex-zones must also be
observed.
Check if the equipment fulfils the safety requirements at site:
After installation a correct earthing connection must be verified. This is normally done through the flange bolt
connection. If this is not the case, the potential or guard wire must be drawn to the terminal clamp.
For trouble-free commissioning of electric actuators, we recommend to call on our specially trained customer
service specialist.
On-site electric installations shall be in accordance with respective connecting diagram of the supplier. In
addition, the specific operating instructions of the actuator supplier shall be observed.
Before the first electrical operation, the Wey Knife gate valve gate shall be set to an intermediate position with
the manual override, and then started.
When connecting to the power supply, the phase sequence has to be observed.
With wrong phase sequence, limit and torque switches are ineffective.
The switch off-shall be in accordance to our instructions/diagrams, i.e.:
- Switch-off in closing direction: usually by limit switches, exceptionally by torque
- Switches (for abrasive service applications).
- Switch-off in opening direction: by limit switches only, as the torque switch serves as overload protection.
5Maintenance
5.1 Inspection
When in operation with dangerous fluids especially the leak-tightness against atmospheric area must be controlled
on a regular basis. At possible indication of leakage must be repacked.
5.2 Operating cycles
During one service year, at least four (4) operating cycles shall take place, whereby all components shall be
checked. Under severe service conditions, such functional checks shall take place more frequently.