O-ring, 88 x 5 mm – Viton, Part# 320522

This is an O-ring. Its part number is 320522. 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 is made for two Pfeiffer DUO pump models :

• Pfeiffer DUO 120A

• Pfeiffer DUO 125

If you own either of these pumps and are doing any internal repair or rebuild, you will need this O-ring.

Not all O-rings are the same. They are made from different materials. This one is made from Viton (also known as FKM or FPM). Here is why Viton is the right choice for your vacuum pump :

• Resists heat: Viton can handle high temperatures up to 200°C .

• Resists chemicals: It stands up to oils, fuels, solvents, and many harsh chemicals .

• Low gas permeability: Viton has very low gas permeability, which makes it excellent for vacuum applications .

• Long lasting: Viton resists weathering, ozone, and aging. It lasts much longer than standard rubber like Nitrile .