Locking Cap, Pfeiffer, UNO, DUO, Part# 192126

This is a locking cap. Its part number is 192126. A locking cap is a specialized fastener. Think of it like a nut or a retaining cap. You screw it onto a threaded shaft or stud.

But a locking cap is different from a regular nut. It has a special design that keeps it from loosening. It “locks” itself in place. This is very important in a vacuum pump, where vibration can cause regular nuts to come loose over time .

This locking cap is made specifically for these pump models :

• Pfeiffer UNO 1.5A

• Pfeiffer DUO 1.5A

If you own either of these pumps and are doing any internal repair or rebuild, you will need this part. In fact, it is included as a standard component in the Minor Repair Kit (Part # 080010) for these pumps .