Demand valve spring tester

[Open Ocean Diver]

Compressing 1/2 in
old 108 6lbs
218 7lbs
216 6.6lbs

I’ll try to measure your way, maybe difficult on the 108 since it doesn’t really have a barrel.

 

[James79]

Compressing 1/2 in
old 108 6lbs
218 7lbs
216 6.6lbs

I’ll try to measure your way, maybe difficult on the 108 since it doesn’t really have a barrel.

If you are dis-assembling a 108 that is already set up (little to no play in the lever), leave the poppet alone to start and pull the inlet fitting. Measure how deep in the bore the poppet face sits. Then remove the poppet, and measure the depth of the bore. Measure thickness of poppet (from face to spring seat on back of face).
[Depth of bore] - [Depth of poppet face in bore] - [Poppet thickness] = [Installed spring length]
Respectfully,
James

 

[Open Ocean Diver]

If you are dis-assembling a 108 that is already set up (little to no play in the lever), leave the poppet alone to start and pull the inlet fitting. Measure how deep in the bore the poppet face sits. Then remove the poppet, and measure the depth of the bore. Measure thickness of poppet (from face to spring seat on back of face).
[Depth of bore] - [Depth of poppet face in bore] - [Poppet thickness] = [Installed spring length]
Respectfully,
James

Thanks good idea.

 

[James79]

Thanks good idea.

That's my one for the week! lol

 

[Open Ocean Diver]

Measure how deep in the bore the poppet face sits.

From the face to the top of the bore or face to the bottom of the bore?

 

[James79]

From the face to the top of the bore or face to the bottom of the bore?

WIth just the inlet fitting removed, you should be able to measure from bore opening (where inlet fitting screws in) to face of poppet. Then remove the poppet, and measure from bore opening to bottom of bore (where the spring seats against the bottom of bore). Then the thickness from face of poppet to back side of poppet face (spring seat). We are indirectly measuring as installed. From full depth of bore, you have [installed spring (that we are solving for)] + [thickness of poppet face] + [depth of poppet face below bore opening].
Diagram pending...

 

[James79]

Hope this helps;

 

[James79]

Numbers are only valid if the measurement of poppet face depth is taken with the reg tuned (little to no play in lever with inlet fitting installed).
Respectfully
James

 

[Open Ocean Diver]

Numbers are only valid if the measurement of poppet face depth is taken with the reg tuned (little to no play in lever with inlet fitting installed).
Respectfully
James

Thanks that helps a lot. It is tuned with good lever height. The face of the poppet is above bore 1 mm.

 

[James79]

Sorry, I had forgotten that the 108 inlet fitting is counter bored... So now the math looks like; [installed spring length] = [depth of bore] - [thickness of poppet face] + [1mm]
That look right?