Nautilus Pac-Fab NS-72 or NSP-72 DE Filter - Parts

Strop

Bronze Supporter
Jul 22, 2017
21
Rancho Santa Margarita, CA
Can anyone tell me the O-ring sizes (not the manufacturer part numbers) for a Nautilus (Pac-Fab) NS-72 or NSP-72 DE Filter and Back-Wash Valve? I have either the NS-72 or NSP-72. The nameplate decal is faded so much I cannot tell if its an NS-72 or NSP-72. I'm curious what the difference is between an NS-72 and a NSP-72 DE filter if anyone knows?

The O-rings I'd like to replace are the following:

1/. Tank O-ring. This is the large (roughly 18") O-ring that seals the tank.
2/. Manifold O-ring. This seals the manifold to the stem pipe inside the filter.
3/. Back-Wash Valve Cap O-ring. This seals the back-wash valve cap in the main housing. The cap is secured with 2 screws. I believe this is the old style (original) back-wash valve.
4/. Back-Wash Valve Shaft O-ring. This seals between the back-wash valve shaft and the cap. The shaft is 3/8" in dia. I think.

Thanks!
 

JamesW

TFP Expert
Mar 2, 2011
17,003
Why not just use the part numbers?

I don't think that anyone is going to have the actual dimensions of the O-rings.
 

Strop

Bronze Supporter
Jul 22, 2017
21
Rancho Santa Margarita, CA
Why not just use the part numbers?

I don't think that anyone is going to have the actual dimensions of the O-rings.
Unfortunately the local pool supply store (think national chain) does not have any of the o-rings in stock. I came up against this issue a few years ago when I did a filter clean and o-ring replacement. I think the local pool supply store only had 1 in stock so I had to reuse all the other o-rings and wait until the next filter clean. This time around none were available which got me thinking if I knew the o-rings sizes then I could source them from McMaster-Carr or a similar specialty hardware supplier. Plus, the pool supply store charges a premium for these o-rings. Why pay 10x the price.