OPERATION & MAINTENANCE INSTRUCTIONS - ORIGINAL VERSION
AVK DOUBLE ECCENTRIC BUTTERFLY VALVES
SERIES 756
OPERATION & MAINTENANCE INSTRUCTIONS - ORIGINAL VERSION
AVK DOUBLE ECCENTRIC BUTTERFLY VALVES
SERIES 756
3.3.2 MAXIMUM PERMISSIBLE FLOW VELOCITY
According to EN593, AVK series 756 butterfly valves are designed for the following velocities fully open in liquid media:
• pressure rating PN 6:
2.5 m/s
• pressure rating PN 10: 3 m/s
• pressure rating PN 16: 4 m/s
• pressure rating PN 25: 5 m/s
3.4 PERMISSIBLE AND IMPERMISSIBLE MODES OF OPERATION
The pressure applied on the closed valve must not exceed the rated valve pressure.
The AVK double eccentric butterfly valve has adjustable mechanical limit stops on the gearbox to ensure a correct open
and closed position. The stops have been set and sealed from factory to guarantee an optimum performance.
Note: Broken stop seals may affect the warranty.
4. INSTALLATION IN THE PIPELINE
4.1 CONDITIONS REQUIRED ON SITE
When the valve is installed between two pipeline flanges, these must be completely aligned. If not aligned, it may result
in impermissibly high loads stressing the valve body during operation which may eventually lead to fracture.
When the valve is installed in a pipeline, make sure it is as tension-free as possible. The pipeline forces transmitted
to the valve must not exceed the values specified in EN 1074-2. The gap between the flanges must be large enough
to avoid damage of the coating on the raised flange face during installation. The pipeline flanges must not be drawn
towards the valve during installation.
If work around the valve may cause dirt (e.g. painting, masonry or work with concrete), the valve must be covered ade-
quately. Assembly in drinking water pipelines requires approved sealing materials, lubricants and process material for
drinking water only. The pipeline sections must be thoroughly cleaned and purified before the valve is set into operation.
4.2 INSTALLATION LOCATION
The location of the valve on site must allow sufficient space for maintenance work.
If the valve is installed in the open air, make sure it is protected against extreme weather conditions (e.g. formation of
ice) by adequate covers.
If the valve is installed as an end-of-line valve, make sure the free outlet side is not accessible for any kind of
interference.
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MI Butterfly756 rev. AC 2018
