How to Maintain your High Vacuum Ball Valve

Ball valve maintenance thumbnail

At ANCORP, we pride ourselves on producing the industry’s leading high vacuum ball valve. Though uniquely different in its stem stabilization and valve lifetime, the ANCORP ball valve is similar to any precision instrument in its need for maintenance. It’s important to understand that even the best valves have wearable internal components that need periodic replacement, depending on your specific application. In this blog post, we’ll guide you through the process of disassembling and reassembling our D, E, and F series high vacuum ball valves to ensure they continue to perform at their best.

Table of Contents

Before You Begin: Verify Your Valve

Before you dive into the maintenance process, take a moment to check your valve. Make sure it has the “XL” stamp on both the top of the valve body and the stem. These markings denote valve’s with ANCORP’s patented Extended Life design.  If you can’t find these markings, you likely have a legacy valve, and you’ll need different instructions and parts to perform maintenance.

Ball Valve Maintenance Kit Checklist

Check Your Kit

It’s essential to verify that all the necessary components are included in your maintenance kit. You should have:

  • Two PTFE seats
  • Two body O-rings
  • One stem O-ring
  • One nylon jam nut
  • One lower PEEK bearing

Also, remember to exercise proper safety and cleanliness measures to protect yourself and prevent any contamination of the internal valve components.

The Maintenance Process: Disassembly and Reassembly

Now, let’s get into the process of maintaining your high vacuum ball valve. Follow the step-by-step instructions for proper disassembly and reassembly or follow along with the video below.

For a print out document of the below instruction, check out the maintenance instructions tab on our manuals and technical data sheets page.


  • Start by removing the handle and the handle stop (manual actuation).
  • Next, carefully remove the body bolts.
  • Lift off the top end cap, making sure to remove and discard the top body seat and O-ring.
  • Remove the ball from the body and set it aside in a clean area.
  • Discard the other PTFE seat and body O-ring.
  • Unscrew the nylon jam nut and remove the upper PEEK bearing.
  • Remove the stem O-ring. You can push the stem down and back up to expose the O-ring for easy removal.
  • Remove the stem by pushing down and take off the lower PEEK bearing.
Expanded View of Ball Valve Components


  1. Begin reassembly by placing the new lower PEEK bearing onto the stem and inserting it through the body.
  2. Put a new generously lubricated stem O-ring onto the stem, followed by the upper PEEK bearing. Ensure that the flat side of the PEEK bearing is facing up and pushed down completely into the body.
  3. Using a crescent wrench to hold the stem, tighten a new nylon jam nut down to the PEEK bearing. Leave it loose enough to finish tightening with a torque wrench set to 7 in-lbs.
  4. Use a torque wrench to complete the stem’s tightening.
  5. Position an end cap with the flange facing down onto a clean table and place a lightly greased body O-ring and PTFE seat on top of the end cap.
  6. Place the valve body on top of the end cap, ensuring that the vacuum arrow is pointing up.
  7. Insert the ball with the evacuation hole facing up.
  8. Place the other lightly greased PTFE seat and body O-ring onto the valve body, followed by the other end cap.
  9. Secure the body bolts to the valve by hand. Tighten the secured body bolts evenly in a diagonal pattern until no gap is present, ensuring even compression of sealed materials.
  10. Secure the stem stop and handle using a wrench to complete the tightening of the bolt (manual actuation).

Final Steps

After successfully reassembling your valve, cycle it three to five times to ensure that the PTFE seats correctly form around the ball. Lastly, perform a leak check on the valve. If it passes, your high vacuum ball valve is ready to get back to work.

Need help completing your ball valve maintenance?

For more assistance on maintaining your ball valve or any questions you might have, please contact us through our contact form, live chat, or call at 1-800-352-6431.