The O-ring service kit for the Divesoft BOV (bailout valve) contains a total of 14 metric O-rings in two different materials, all of which are not required at the same time; see discussion below. The kit contains TWO Each of the following O-rings:

• 2x O-rings size 16x2 EPDM
  
  
• 2x O-rings size 21x2 EPDM
• 2x O-rings size 21x2 MVQ
  
  
• 2x O-rings size 37x2 EPDM
• 2x O-rings size 37x2 MVQ
  
  
• 2x O-rings size 41x2 EPDM
• 2x O-rings size 41x2 MVQ

If your Divesoft BOV knob is difficult to turn or is leaking, Divesoft strongly recommends the unit be returned to a Divesoft authorized service center rather than attempting to service in the field. However, a technician trained to service the Divesoft BOV provided us with the following information:

The MVQ (Red) O-rings are softer and reduce the turning effort on the BOV. On some older units the tolerances of the material require use of the EPDM (Black) O-rings, which are firmer than the red versions. On an older BOV the technician may need to 'mix-n-match' the two types of O-rings to get the lowest turning effort yet still achieve an effective seal. Unfortunately, the only reliable method to test for an effective seal is by pressurizing the BOV while underwater using a proper test apparatus. Sometimes the BOV and rebreather assembly will pass a simple positive and negative pressure test when dry, but seals may still leak once diving if the BOV was not properly tested underwater.

Please only use oxygen compatible high-performance lubricant, either Tribolube 71 (formulated specifically for closed-circuit SCUBA applications) or alternatively the factory recommended Krytox GPL-201 general purpose lubricant. Do NOT use silicone based lubricants and do not use Christo-lube. Unlike conventional wisdom regarding lubrication, in this specific circumstance the generous application of lubricant is advised. Use a syringe to thoroughly apply lubricant directly in to the O-ring grooves; once the BOV is assembled the excess will extrude and may then be wiped off.