ASAHI AV VALVES Installation Operation and Maintenance Manual
Butterfly Valves Type57L-IS (Lug style) 6
(6) Installation procedure
- When suspending and supporting a valve, take care and do not stand under a suspended valve.
- Be sure to conduct a safety check on all hand and power tools to be used before beginning work.
- Wear protective gloves and safety goggles as fluid remain in the valve even if the pipeline is empty.
(You may be injured.)
- When installing a pipe support by means of a U-band or something similar, take care not to over-tighten.
(Excessive force may damage the pipe.)
- When installing pipes and valves, ensure that they are not subjected to tension, compression, bending,
impact, or other excessive stress.
- Use flat faced flanges for connection to AV Valves.
- Ensure that the mating flanges are of the same standards.
- When installing the piping, do not do so with the valves fully closed.
(The disc may pinch into the seat, resulting in a high operating torque, thus disabling opening and closing.)
- The gasket is unnecessary. (The seat carries out the role of the gasket.)
- Do not use AV valves in a place where they may become submerged in water.
(Submergence will make AV valve fail.)
- Care must be used during piping installation to ensure that
the pipes or flanges are properly aligned so that the valve
disc does not contact them in any setting. Misalignment
as in Figure below will result in damage
- The valve disc is sent in the position indicated by solid lines in
Figure prior to shipment from the factory. If the valve is
opened or closed after unpacking, it must be reset in this position
before installation. Failure to do so will result in damage to the
surface of the valve seat during handling and installation.
In case of the thick wall of the connection part (flange and pipe) is too thick, shave the flange or the pipe inside in order to
avoid the contact of pipe and disc. If inside diameter of the connection part is larger than size D, shaving is not necessity.
Nominal Size Diameter D
3” (80mm) 2.64” (67mm)
4” (100mm) 3.58” (91mm)
6” (150mm) 5.47” (139mm)
8” (200mm) 7.28” (185mm)
INTERFERENCE OF THE DISK