O.T.Hydraulic Seal Questions

**Bobnotthecat** · 11-13-2019, 10:45 AM

Sirs,

I am wanting to know if polypack is just a trade name for a loaded lip seal or are they different products altogether.

Please elucidate.

Thanks,
Bob

**4GSR** · 11-13-2019, 10:56 AM

"Polypac" was the original by Parker Seal division. Over the years, it has been copied and different variations of it are now offered out there under different trade names.

Edit: Polypac is energized by a O-Ring in the middle of the two lips of the seal. They are the original to the lip seal design. Now days, you find them with a metallic spring installed in place of the O-Ring for more advance sealing systems.

I've used many of the various variations out there today for some of the equipment I've designed over the years.

Ken

**R. Dan** · 11-13-2019, 02:25 PM

Trade name for a Parker loaded u-cup: https://www.parker.com/literature/En...20Profiles.pdf

We used them for rod seals in cylinder glands.

**Bobnotthecat** · 11-13-2019, 09:10 PM

Thanks guys. That is good to know.

I have found on some parts list calling for a polypac seal when apparently just a loaded u lip seal would serve.

Polypac seals seem to be very overpriced.

Thanks again,

Bob....not the cat.