Scubapro O-ring Sizes

[redacted]

Scubapro uses their own part numbers for o-ring (01-050-xxx) that have little correlation with standard o-ring sizes. I have worked up a correlation between SP part # and standard o-rings sizes for all applications I use in my Mk2/5/7/10/20, 108/109/156/R190/D-series/G500/S600/Air2, as well as hoses and others items. So let me try to get it started and see what we can do. Your comments, questions, and corrections are more than welcome. I'm sure this may get messy but some smart organized guy like couv will probably come along and clean it up. Metric sizes are width x ID.

SP # Std # Duro Note
109 003 70 SPG spool, duro 90 harder to install
117 006 70
126 008 70
127 008 90 I use a doro 70 and it works OK
132 010 70
136 010 90 Mk20/25 piston
137 010 90 Mk5/7/10 I use urathane
138 011 70
142 011 70
144 012 70
147 013 70
152 013 70
157 014 70
160 015 70
161 017 70
162 017 70
177 022 70
179 022 70
184 023 70
193 111 90
196 112 90
211 116 70 D-series switch (round peg in a square hole)
217 117 70
258 214 90
293 902 70 slightly thinner than a 010
322 117 70
323 1x4 70 metric D-series - not yet tested
342 012 70
347 014 90 yoke valve
351 011 70 not sure, could be
351 903 70 ??
375 1.5x7 70 metric, this works but is a bit thick
375 1x8 70 metric. I did not try this but 1x7 is too small
380 015 70 duro 90 may be better
385 109 70
399 1x2.2 70 metric
363 1x2.2 70 metric


It's a start.

Edit: See, told you it would be messy. Spacing lost but I think it is still readable.

 

[aquaregia]

Here's a chart with o-ring generic sizes. My LHS lists them in sixteenths rather than -xxx.
http://www.allorings.com/size_cross_reference_framed.htm

 

[Zung]

[table 0 0 0 0]SP.....|Std.....|Duro..|Note
109|003|70 |SPG spool, duro 90 harder to install
117|006|70 |MK 14, AIR2, BPI
126|008|70|MK 2+, R series, G series, S series, AIR2, BPI
127|008|90|I use a duro 70 and it works OK
132|010|70|
136|010|90|Mk20/25 piston
137|010|90|Mk5/7/10 I use urethane
138|011|70|
142|011|70|
144|012|70|
145|012|70|G250HP Bal. Chamber Piston
147|013|70|
152|013|70|
157|014|70|
158|015|70|MK 2+
160|015|70|
161|017|70|
162|017|70|
177|022|70|
179|022|70|
184|023|70|
193|111|90|
196|112|90|
211|116|70|D-series switch (round peg in a square hole)
217|117|70|
258|214|90|
293|902|70|slightly thinner than a 010
322|117|70|
323|1x4|70|metric D-series - not yet tested
342|012|70|
347|014|90|yoke valve
351|011|70|not sure, could be
351|903|70|??
375|1.5x7|70|metric, this works but is a bit thick
375|1x8|70|metric. I did not try this but 1x7 is too small
380|015|70|duro 90 may be better
385|109|70 |
399|1x2.2|70|metric
363|1x2.2|70|metric
[/table]

I'm no friend of HTML.
Including a text file for editing (edit, then copy/paste), and an Excel file too.

 

[AquaNSun]

I have a different size on the Mk2 O-ring and would like to confirm it. Couv sent me an annotated schematic of the Mk2 a while ago and the difference is the piston head o-ring which he has was 021 instead of 022. Wonder which one is correct? Thanks.

SP, size, Duro
Couv version: 177, 021, 70
This version : 177, 022, 70

 

[Zung]

I don't have a MK 2, but according to a SP doc about metric sizes, the 177 is 25.0 x 1.78 (mm), which is a 022. The SP doc that comes with the kits also states that the MK 2, 20 and 25 all use the same 177. The 021 is 23.5, roughly -5%; it may work, but it's quite a stetch.

 

[AquaNSun]

What's a "SP doc about metric sizes?" Is that an official SP sizing chart in metric?
Thanks for the confirmation Zung!

 

[redacted]

What's a "SP doc about metric sizes?" Is that an official SP sizing chart in metric?
Thanks for the confirmation Zung!

A while back when Scubapro packaged kits in small plastic packages, they included a "kit table P/N 45-078-101 (a packing slip) that had a list of annual service o-rings and their metric sizes. I'll post that after the game (tomorrow).

 

[halocline]

Couv has those nice annotated diagrams. I'll try to attach a MK10 one, I'm sure he won't mind.

 

[halocline]

One other thing, I got in the habit of using polyurethane o-rings for both the piston stem and head on MK5/10s, mostly because SP sent those in their kits for a while. I had great results with some of the 90 duro 010 o-rings; others just crumbled on installation. I think we might have gotten a bad batch at one point. Anyhow, I think it's worth it to spend the money (an extra dollar or two for several) especially considering the money you save doing DIY service.

Couv, who seems to know everything about o-rings, uses viton for a lot of applications. I read that viton has crummy abrasion resistance and have avoided it for use in dynamic applications, but I think Couv mentioned that it's actually not bad as far as abrasion/extrusion goes.

 

[redacted]

according to Parker Bros., Viton and EPDM are similar for scuba applications characteristics with EPDM having a small advantage in abrasion and tear resistance. Viton tends to be more expensive but also has a longer shelf life. Polyurethane has excellent dynamic characteristics including resistance to extrusion which makes them good for HP piston o-rings where extrusion can be a problem.

SP metric o-ring sizes:

SP# ID Wd
117 2.9 1.8
126 4.5 1.8
132 6.0 1.8
136 6.0 1.8
138 7.7 1.8
145 9.3 1.8
158 14.0 1.8
177 25.0 1.8
363 2.2 1.0