INSTALLATION & MAINTENANCE INSTRUCTIONS - ORIGINAL VERSION
AVK BUTTERFLY VALVES, CENTRIC WITH LOOSE LINER
SERIES 820
4. PRECAUTIONS TO BE TAKEN PRIOR TO INSTALLATION
Please make sure that the valve is suitable for the prevailing service conditions. The plant manager is responsible for using the
right valve (with regards to corrosion resistance, pressure, temperature, etc.)
for the actual fluid. Contact your supplier or AVK if you need any assistance.
Please consider that turbulence (i.e. created by a pipe bend) generates hydro dynamic forces which increases the operating
torque of the valve. We recommend to install the valve minimum 5 x DN after
pipe fittings.
5. CHECK BEFORE INSTALLATION
Positioning:
In horizontal pipelines, we recommend that the valve is
installed with its shaft in a horizontal position. Please ensure
that the lower edge of the disc opens with the direction of the
flow. This prevents residues and contamination in the shaft
sealing area (fig. 2).
Gaskets:
Never use gaskets nor grease (fig. 3).
6. INSTALLATION
The flange face surfaces must be smooth and clean. Rust, welding slags, remains of paint, dirt etc. must be removed in order to
prevent damage of the valve gasket.
The wafer butterfly valves are suitable for installation between standard DIN PN10/16 or ANSI150 flanges. For installation of
valves between flanges of other standards, please consult AVK or its authorised distributors.
The valve should not be mounted directly in pipes, where the actual bore dimension is smaller than the nominal bore dimension
of the valve. In such cases, spacer rings should be fitted between flanges and valve to prevent damage to the disc when open-
ing (fig.4). The valve should never be installed between flanges which are not parallel to each other. Make sure that pipes and
valves are installed concentric as the disc of a misaligned valve may be damaged (fig.5). Furthermore, it is absolutely inadmis-
sible to carry out any welding on the piping while the valve is mounted between the flanges. This would damage the liner of the
valve.
For easy installation the flanges have to be positioned properly and the disc must be partially open (fig. 6). If the flanges are not
positioned properly the liner may be damaged or rolled outside the body flanges.
Set all stay-bolts by keeping the disc slightly open and do not tighten the nuts (fig. 7). If the stay-bolts are tightened when the
disc is closed, the liner will be compressed in a wrong position. This will result in a high closing torque and leakage.
Open the disc completely (fig. 8). Ensure that the piping is aligned. Tighten diagonally opposite the nuts.
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MI Butterfly820 rev. C August 2017 GB
FIG. 4
FIG. 5
FIG. 6
FIG. 7
FIG. 8
Fig. 2
Fig. 3
