ASAHI AV VALVES Installation Operation and Maintenance Manual
Butterfly Valves Type57L-IS (Lug style) 2
(2) General operating instructions
- Using a positive-pressure gas with our plastic piping may pose a dangerous condition due to the repellent
force particular to compressible fluids even when the gas is under similar pressures used for liquids.
Therefore, be sure to take the necessary safety precautions such as covering the piping with protective
material. For inquiries, please contact us. For conducting a leak test on newly installed piping, be sure
to check for leaks under water pressure. If absolutely necessary to use a gas in testing, please consult
your nearest service station beforehand.
- While removal of valves from pipeline or during maintenance, please take precautions to protect worker.
- Before removal of valves from pipeline, make sure to empty the line so no liquid is remaining. Then
take off bolts at the downstream side first. (It is dangerous taking off bolts at the upstream side first. It
causes the valve drop out from pipeline.)
- Lug Butterfly Valve is designed for being
able to maintain SHUT OFF POSITION at
the disconnected downstream side pipeline
while connected to upstream side pipeline.
(This valve has flow direction. Therefore do
not take away the upstream side bolts. ※
Caution: If you take off the upstream side
with out stopping and emptying at upstream
side, there will be leakage on both side.)
- While removal of a flange on downstream side, draw out fluids from removing side pipeline completely.
※Maintaining low pressure on upstream side will ensure safety.
- Do not step on or apply excessive weight on valve. (It can be damaged.)
- Do not use AV valves in a place where they may become submerged in water.
(Submergence will make AV valve fail.)
- Do not use the valve in conditions where the fluid may have crystallized. (The valve will not operate properly.)
- Keep the valve away from excessive heat or fire. (It can be damaged, or destroyed.)
- Always operate the valve within the pressure vs. temperature range.
(The valve can be damaged or deformed by operating beyond the allowable range.)
- Allow sufficient space for maintenance and inspection.
- Select a valve material that is compatible with the media. For chemical resistance information, refer to
“CHEMICAL RESISTANCE ON ASAHI AV VALVE”.
(Some chemicals may damage incompatible valve materials.)
- Keep the valve out of direct sunlight, water and dust. Use cover to shield the valve. (The valve will not
- Perform periodic maintenance. (Leakage may develop due to temperature changes or periods of prolonged
storage, rest, or operation.)
- Before opening or closing a lubricant free product, be sure to apply water.
- If you install this valve to the end of the piping, we recommend to use
the “Blind Flange” at the opposite side of the valve to prevent
accidental opening of the valve.
Downstream side U