These fluorocarbon elastomer (aka Viton™, aka FKM, aka FPM) O-rings are brown color and 90-duro (except for the -003 O-rings, which are 75-duro). They are well suited for the SCUBA applications we describe, especially suitable for use with Nitrox. Five of each size o-ring are packaged in individual resealable plastic bags that are each labeled with the size and all ten small bags are further packaged in a larger bag that also includes a copy of the AS568 size and SCUBA application table shown below. Packaging the o-rings in this manner is much preferred over the typical box with small compartments. The plastic bags make the entire kit much more compact to store, is more durable, allows individual sizes to be redistributed as needed, helps keep the o-rings clean, and reduces the chance of the different size o-rings being mixed up or co-mingled.
AS568-
Outside Diameter
SCUBA Application Seal
214
1-1/4
Cylinder with Large Neck/Valve (3/4 NPSM - All Aluminum, most Steel cylinders, also M25)
112
11/16
Standard DIN Regulator/Valve (Nearly all DIN regulators)
111
5/8
Small DIN Regulator/Valve (You know if you need this one)
015
11/16
Cylinder Valve Bonnet Nut
014
5/8
Standard Yoke Regulator/K-valve
013
9/16
Large Low-Pressure Port/Hose (1/2 UNF)
012
1/2
High-Pressure Port/Hose (7/16 UNF) Manifold and Manifold Port Plugs
Designers of modern SCUBA equipment often specify O-rings with special properties and materials for specific uses inside their equipment. The special o-rings are supplied as part of original equipment manufacturer (OEM) service parts kits. Substituting any other generic O-ring just because it's the right size can cause difficult-to-diagnose problems and degrade performance. Improper service could cause a failure which would have serious and life threatening consequences.