Industrial Valve Seat Repair and Maintenance
These Valve Seat Lapping processes are well established, repeatable and used worldwide by major multi-national seal and valve manufacturers as well as maintenance departments of oil and gas installations.
Scope of Work: To lap flat two seats showing two process finishes, one lap, and one polish
Equipment used for Stage 1 (Lap):
Equipment used for Stage 2 (Polish):
- Kemet 15” lapping/polishing machine
- ASFL polishing cloth
- Kemet Flatness gauge
- 3 micron type K std
- Co42 cleaning fluid
- Plastic faced control ring
- Profiled workholder
Process breakdown for Valve Seats
2 x seats were placed in a 15” control ring on a flat kemet copper SP2 plate and run for 5 minutes to remove damage and clean up; parts were then checked for flatness. 1 x seat was then placed in a plastic faced control ring and run on a ASFL polishing cloth for 2 minutes.
Damaged Valve Seat
Stage 1 clean-up
Stage 2 polish
1 Lightband on Valve Seat
After Stage 1
1 Lightband on Valve Seat
Scope of Work: To lap 4 bevelled surfaces on 2 different sized check valve seats to Drg requirements
Equipment used:
- Kemet SPM Spherical Polishing Machine
- Purpose made fixturing
- 2 x machine ball laps
- 9.3 micron silicon carbide paste
- OS Lubricating fluid
- Co42 cleaning fluid
Process breakdown for Check Valve Seats
1 x check valve seat was placed into the 3 jaw chuck with the bevelled face that needs lapping facing up, a small amount of 9.3 micron silicon carbide paste was applied to the face and to the machined lap tool which is then slid into the arbour sleeve by the drive pins locating in the slots each side, some OS lubricating fluid is applied to the bevelled face and the lap is then lowered onto, with the desired sweep and drive speeds adjusted to suite the machine is run for 5 minutes till face appears cleaned up, the check valve seat is then removed and cleaned with Co42 cleaning fluid.
Before processing Check Valve seat
