Racor Gasket/Oring code cracked

[P69]

I cracked the code for Racor gaskets/o-rings, at least for Racor 500. 

I measured each O-ring in my Racor 500 and found identical matches on McMaster.com

I could not find the beveled "o-ring" for the internal check valve.  I also could not ascertain the material of the O-rings; however, based on what is available and the color, the red ones are high temperature silicone. The black are BunaN.   During this process, I learned that O-rings are standard with specific "Dash" numbers for each diameter/thickness.   An O-ring with Dash number of 237 will always have the same OD and ID, regardless of cross-section shape.  Because of this standardization, devices are likely designed around the available parts.  It is likely that Racor designed the filters around the available Dash number system, rather than designing a filter, then making an o-ring to fit that filter.

The very interesting part is that a set of Rings (T Handle, Lid, body, drain port, WIF port, heater port, input/out ports) coast fewer than $2.00.  downside is that (at least with McMasters), you buy a quantity, not individual rings. The packages are cheap.  $10/25 rings for the body/bowl interface, < $4 for the WIF sensor port, the BOSS o-rings are $5 or $6 per 100 rings.  One purchase buys you a lifetime supply you become the best friend of everyone on the dock because you ave them $30 - $50 for set from Racor. Yes, that's $30 - $50 vs < $2 for one set.

I know that the filters come with T-Handle and lid rings, but the others are a phenomenal rip-off.  The input/output ports are nothing special, just J1926 SAE ORB straight thread ports (o-rings:  $6/100).  There are places that sell individual ORB o-rings (www.discounthydraulichose.com) for $0.30 to a couple of bucks), but for about $50 you can get  essentially a lifetime supply with the limiting quantity being the lid an bowl o-rings (25/pack).

I realize that the o-rings don't get changed much, but they should be changed more than we change them.  I had a Racor 500 for about 3 years and the body/bowl o-ring was cracked.  After I paid $35 for a "Racor Seal Service Kit - RK 1521", I decided to find another source.  That was just too much of a rip off, especially when I don't use half of the rings in that kit. That's about $35 for 4 rings!

Dash sizes are little confusing.  O-rings has a Dash number  and SAE fittings have another Dash number.  For example, the Dash number for the o-ring for the 3/4" x 16 tpi fittings for the input/output ports on the newer design of the Racor 500 is Dash #8 (for the metal fitting). The Dash number for the o-ring is 908. The Dash number for the older model 500s is Dash #6 for the metal fitting and Dash 906 for the o-ring.  Hey. there is a pattern there.  I just noticed that.  One of y'all can follow that rabbit hole.  Anyway, Dash numbers for o-rings appear to be standard and they are different from the Dash number system for the metal fittings.

If you are ever in need of a Racor o-ring, ask local places about Dash numbered o-rings.

Attached is a quick-reference to McMaster.

I'll upload the full documentation (spreadsheet, PDF, SAE pdf from Racor explaining J1926 fittings to the Documents Library section.

UPDATE: Documents uploaded: https://pearson365.com/forum/index.php?board=26.0

[S/V AMITY]

Great info.!  Once cracking the code for the rings, good to keep a log of the o-ring numbers for their respective applications & keep plenty of spares aboard.