K Type BCD Inflator Valves Parts II and III

[divezonescuba]

Back in 2019, I posted a youtube video about the seemly similar, but actually different K type inflator valves commonly found on wing systems.


Since that video, another variant has hit the market. Rather than updating the video, I have posted the information about this new variant. I am posting it here as well.

Since this video, in 2020, a third version has appeared. This is an OEM inflator made by Ocean Diving Systems and used by some BCD manufacturers. It is distinguished by grey inflation and deflation buttons. It also has a manufacturer code of ODS and a date stamp on the rim of the inflator assembly cartridge.

This k inflator cannot be easily disassembled for oring maintenance. BCD manufacturers who use this inflator, recommend not attempting to service the orings and to just replace the entire inflator or inflator cartridge assembly. You cannot be guaranteed to be able to find a compatible inflator or inflator cartridge on a trip. So, your choice in this situation is to either carry an additional inflator or inflator cartridge on any trip.

Alternatively, you can replace the non-serviceable inflator cartridge with one that can be disassembled and serviced. Fortunately, the plastic inflator housing is sufficiently compatible with other versions of this for the serviceable inflator cartridges to be a direct replacement. This is the approach which we recommend.

 

[divezonescuba]

Update to the update:

After encounterin the above difficulty, I posted questions on if anyone know how to disassemble this particular type of K-valve. I did not receive any suggestions. In the meantime, manufacturers were telling me to discard the existing inflator cartridge. This continued to bother me from an engineering standpoint, so I continued to investigate how it was not possible to disassemble the cartridge.

The ODS inflator can actually be disassembled with the correct tools and some perseverance. It is difficult to disassemble due to the fact that the internal shaft has threads on both ends. While unscrewing, it is likely that the grey inflator button will unscrew leaving the shaft captive inside the inflator cartridge housing. In order to service the oring, the shaft must come out.

To do this, the top of the shaft where the button was needs to be pressed as far as possible into the housing. There is then sufficient clearance to hold the shaft with a small pair of needlenose pliers at the bottom of the housing. The nut on the bottom that was used to screw off the button, can now be used again, this time to uscrew the nut on the bottom of the shaft. The shaft might get scored slightly by the needle nose pliers in this process, but since that part is not a sealing surface, it will not cause any problems. Make sure you tighten the end nut sufficiently or use lock time when reassembling.