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How to Install and Maintain a Butterfly Valve
Date:2026-05-21 14:20:54 Author:Zhejiang Kinko Fluid Equipment Co., Ltd

1. Critical Rule Before Installation

Always install with disc partially open (10–20°). Never install with disc fully closed – it will damage the seat and pipe flanges.


2. Installation – Wafer Type (Most Common)

StepAction
1Disc at 10–20° open
2Place valve between flanges with gaskets both sides
3Insert long bolts through both flanges
4Hand-tighten, then close disc fully
5Tighten bolts in star pattern (50% → 75% → 100% torque)

Common mistakes:

  • Over-tightening → crushes body, binds disc

  • Under-tightening → flange leakage

  • Missing gaskets → metal-to-metal leak


3. Installation – Lug Type

StepAction
1Disc at 10–20° open
2Place valve between flanges with gaskets
3Bolt upstream flange to upstream lugs (short bolts)
4Bolt downstream flange to downstream lugs
5Tighten both sides in star pattern

Lug advantage: Allows dead-end service and downstream pipe removal without system drain.

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4. Post-Installation Testing

TestAcceptance
Visual checkNo external leakage
Manual operationSmooth 0° to 90° rotation
Seat leakage (closed, pressurized)Zero bubbles (bubble-tight)

5. Maintenance Schedule

FrequencyTask
MonthlyCycle valve (if normally static) to prevent seat sticking
QuarterlyCheck bolt torque, lubricate stem
AnnuallyInspect seat and disc for wear/damage
As neededReplace seat (in-line for wafer/lug – 30-60 min)

6. Seat Replacement – Concentric Valve (In-Line)

StepAction
1Depressurize and drain line
2Remove actuator/lever
3Remove stem and disc
4Pull out old seat, clean groove
5Install new seat, reassemble

No need to remove valve from pipeline.


7. Common Problems & Solutions

ProblemCauseSolution
Leakage (closed)Worn seatReplace seat
Leakage at stemWorn O-ringTighten gland or replace seal
High torqueOver-tightened boltsRe-torque
High torqueSeat swelling (chemical attack)Replace with compatible material
Sticking after sittingSeat bonded to discCycle manually (carefully)
Flange leakageLoose bolts or bad gasketRe-torque or replace gasket

8. Storage Guidelines

RuleReason
Store with disc slightly open (5–10%)Prevents seat from taking permanent set
Dry, indoor locationPrevents corrosion and UV/ozone damage
Do not stack heavy itemsProtects body and disc

Never store with disc fully closed.

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9. Safety Reminders

  • Depressurize and drain before maintenance

  • Allow hot media to cool

  • Use LOTO (lock-out/tag-out)

  • Use lifting aids for valves ≥12"


10. KINKO Maintenance Support

AvailableDescription
Spare seat kitsEPDM, NBR, Viton for KBF-LT series
Stem seal kitsO-rings, packing, gland hardware
Full rebuildReturn to KINKO for factory service

11. Conclusion

Proper installation (disc partially open + correct torque) and regular maintenance (monthly cycling, annual inspection) will maximize butterfly valve life. Most failures are preventable.

Contact KINKO for spare parts kits or technical support.

Ivan (Mobile:+86-18968769287)
          WhatsApp:+86-13579991606

Wechat:+86-18968769287

Website:www.kinko-flow.com
ZHEJIANG KINKO FLUID EQUIPMENT CO.,LTD


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