PTFE lined butterfly valves are assembled with bolts by carefully aligning the valve between pipe flanges and securing it using stud bolts or through bolts, depending on the valve's hole configuration. The process involves calculating the correct bolt length, ensuring proper alignment, and tightening the nuts to create a secure, leak-proof seal. These valves are designed for chemical resistance and efficient flow control, making their correct assembly crucial for performance.
Key Points Explained:
-
Valve and Flange Alignment
- The ptfe butterfly valve is positioned coaxially between two pipe flanges.
- Bolt holes (typically 2 or 4) in the valve body align with threaded holes or through holes in the flanges.
- Some valves have internal threads, while others allow bolts to pass through entirely.
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Bolt Selection and Calculation
- Bolt length is determined by:
- Standard bolt length
- Nut thickness
- Valve body thickness
- Spring pad and flat pad thickness
- Additional margin for secure fastening
- Full-threaded stud bolts are commonly used for uniform clamping force.
- Bolt length is determined by:
-
Installation Process
- For threaded holes:
- One nut is removed from the stud bolt.
- The bolt is twisted into the valve's threaded hole.
- The nut is then tightened to secure the flange connection.
- For through holes:
- Longer bolts pass entirely through the valve and flanges.
- Nuts are tightened on both ends to clamp the assembly.
- For threaded holes:
-
Tightening and Sealing
- Bolts must be evenly tightened to prevent distortion of the PTFE lining.
- Proper torque ensures a tight seal without damaging the valve's chemical-resistant lining.
- Spring washers or flat pads may be used to distribute pressure evenly.
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Post-Installation Checks
- Verify alignment to avoid flow obstruction.
- Inspect for leaks under low-pressure testing before full operation.
- Ensure the butterfly disc operates smoothly after bolting.
This assembly method ensures durability and leak-free performance in aggressive chemical environments. Have you considered how bolt material compatibility (e.g., stainless steel) affects long-term valve reliability?
Summary Table:
| Step | Key Details |
|---|---|
| Alignment | Coaxially position valve between flanges; match bolt holes (2 or 4). |
| Bolt Selection | Calculate length: valve thickness + nut/pad thickness + margin. Use stud bolts. |
| Installation | Thread bolts into valve or pass through flanges; tighten nuts evenly. |
| Tightening | Apply uniform torque to avoid PTFE lining damage; use spring washers if needed. |
| Post-Checks | Test alignment, leaks, and disc operation before full use. |
Ensure optimal performance of your PTFE lined butterfly valves with precision assembly. Contact KINTEK today for expert guidance or custom valve solutions tailored to your chemical processing, semiconductor, or industrial needs. Our PTFE components (seals, liners, labware) are engineered for durability and compatibility in aggressive environments—from prototypes to high-volume orders.