Trouble Shooting

External Leakage

Applicable product

• Butterfly Valves

Leakage occurs from the connection area between the butterfly valve and flanges.

① When the valve is pushed in a narrow space between the pipe flanges, the rubber seat may be deformed, leading to leakage.
When installing the valve to the pipe, use jack bolts as needed to adjust the space between the pipe flanges.At this time, allow 6 to 10 mm extra space between the pipe flanges compared to the space between the valve surfaces and then insert the valve.

Do not tighten the bolts at this time. Gradually tighten the bolts evenly and alternately in a star pattern to avoid uneven tightening. Tighten the bolts until both flanges come into contact with the valve body.
* If the bolts are further tightened even after the flanges come into contact with the valve body, the valve body may be damaged.
* Do not use an impact wrench to tighten the bolts.
Refer to our operation manual for more details on valve installation.

② The pipe on the upstream and the one on the downstream may not be properly aligned. When installing the valve, be sure to align the center of the valve with that of the pipes. In doing so, be careful that excessive piping stress is not applied to the valve.

③ If the bolts are tightened unevenly, external leakage may occur.
Do not tighten the bolts at a time to avoid uneven tightening. Tighten the bolts evenly and alternately in a star pattern.

Body Crack

Applicable product

• Butterfly Valves

The valve body of the butterfly valve was cracked.

① When the butterfly valve is pushed in a narrow space between the pipe flanges, the valve body may be cracked.
When installing the valve, use jack bolts as needed to adjust the space between the pipe flanges.
At this time, allow 6 to 10 mm extra space between the pipe flanges compared to the space between the valve surfaces and then insert the valve.

② When the butterfly valve is installed without the proper alignment of the upstream pipe with the downstream pipe, the valve may be exposed to excessive stress, leading to cracking of the valve body. When installing the valve, be sure to align the center of the valve with that of the pipes.

③ If the bolts are tightened unevenly, excessive stress may be locally applied, leading to cracking of the valve body.
Do not tighten the bolts at a time to avoid uneven tightening. Tighten the bolts evenly and alternately in a star pattern.

Refer to our operation manual for more details on valve installation.

Oil Leakage

Applicable product

• Ball Valves
• Butterfly Valves
• Check Valves
• Gate Valves
• Globe Valves

When I tried to install the valve, oil came out.

For our standard products, oil and grease are applied for the purposes of lubrication and rust prevention.
Contact us in case oil-free products are required.