O-ring, 22 x 3.0 mm – Viton, Part# 320179

This is a Viton O-ring. Its part number is 320179 . An O-ring is a simple loop of elastic material. Its shape is a perfect circle. When you look at a cross-section, it looks like the letter “O”. That is where the name comes from .

You place this O-ring into a groove between two metal parts. When you tighten the parts together, the O-ring gets squished. It fills the tiny gap completely. This creates an airtight, leak-proof seal . This O-ring measures 22 mm on the inside and has a thickness of 3.0 mm .This O-ring is made for the Pfeiffer DUO family of vacuum pumps . It is a versatile seal used across multiple DUO pump models. A very similar O-ring (22 x 3 mm – Viton, Part # 23970410) is also used in Pfeiffer DUO 5, DUO 5C, DUO 10, and DUO 10C pumps, as well as Leybold Trivac and Sogevac pumps . While that is a different part number, it shows that the 22 x 3 mm size is a common and important seal in many vacuum pumps.