solution for D-series poppet seat DIY?

[halocline]

The pilot used an o-ring for the seat in much the same way that you did. Glad it worked. I bought a bag of 50 poppets with seats installed several years ago. I sold several of them, now I have just about enough for the next 20 years, which should be enough dive time for me.

 

[Kupu]

Today I enjoyed two hour long dives using the AIR1 with oring seat. It performed flawlessly, the oring seat works as well as original seat.

Next step will be to try the other two oring sizes I purchased for this experiment, and also test this hack in old D series.

 

[lexvil]

Good news

 

[lexvil]

Kupu sent me one of these o rings, I tried it, not in an overall controlled way but as part of a question on the D420 poppet into an older series, first off the poppet can work but it need modification, it needs one of the seat holders with the “wings” for centering, the D420 has them as part of the “valve body” and the “friction reducer” at the bottom needs to have the diameter reduced, it’s about 20 thousandth of an inch fatter.

While trying the red o ring I had it extrude, so I put the 420 seat in and moved on to other angles and actually have an AIR1 running a modified D420 poppet.

On a whim yesterday morning after wondering about Simon’s old 420 and it’s resistance to fine tuning, it would adjust up to great breathing but I would get a dribble of air between breaths so I wondered about the red 104 silicone o ring as a seat? Took it apart and the stock seat had quit a set to it, I put the 104 in it and not only is it holding perfectly and has been under pressure for 24 hours it has also changed the dry performance of the 420! At the moment it cracks with no effort, it’s breathing like an air 1 in the shop!!

I plan to take it in the pool for some in water testing and maybe put it on a 40 for ocean testing if it seems to hold up. I’ve ordered 30 more of the o rings just to have them on hand.

 

[Kupu]

Interesting information about your work with the D420 poppet and look forward to hearing more!

Curious to know more about the extrusion problem. I did run into sealing issues if the poppet cap nut was tightened too much, overtightening would break the seal and result in a free flow. Is your issue different?
Installing the nut to hand tight and then adding 1/8 turn with wrench is what I have been doing. Going much tighter creates an issue. Thought about using a bit of locktite as insurance in that situation.

I have taken the oring seat AIR1 on 6 dives now, and also 2 dives with a converted pilot switched to oring seat poppet. Both poppets issue free and breathing like a dream.

 

[Kupu]

I had a look at D420 diagram, to see differences in poppet design.
Do you see a reason why the oring extruded on D400 poppet but worked D420 poppet?

 

[lexvil]

Hi Kupu,
The extrusion was from the anti friction cap on the 420 poppet hanging up in the body, I actually have it in an AIR 1 with the little plastic cap removed while I wait for time to turn it down more.

I only tightened the nylock nut to about the same place it was with the stock seat. Another issue for the AIR1 is the height of the poppet at the nut end, I did modify the spring adjuster by cutting the nipple end off and sealing it so I can get full opening, not wanting to modify the poppet was my concern at the time but grinding the top down will be a better solution once the poppers become more common.

 

[lexvil]

just did a short pool dive with the 420, perfect.

 

[Kupu]

Hi Kupu,
The extrusion was from the anti friction cap on the 420 poppet hanging up in the body, I actually have it in an AIR 1 with the little plastic cap removed while I wait for time to turn it down more.

I only tightened the nylock nut to about the same place it was with the stock seat. Another issue for the AIR1 is the height of the poppet at the nut end, I did modify the spring adjuster by cutting the nipple end off and sealing it so I can get full opening, not wanting to modify the poppet was my concern at the time but grinding the top down will be a better solution once the poppers become more common.

Gotcha. My mind being focused on the old style poppet resulted in a reading comprehension fail.

 

[lexvil]

Gotcha. My mind being focused on the old style poppet resulted in a reading comprehension fail.

I hoping to get a few hours of dive time before I pull it (420) apart to see how the o ring is holding up.