Montaje de reguladores de diafragma

[MARK74]

Hi guys
I would like to know the assembly protocol that you follow for the first stages of the diaphragm.
When I trained as a technician, they taught me to mount the HP side first, check for leaks, and then the LP side.
The Scubapros, which are the ones I use, say this in their manuals, however the manuals of other brands say the opposite. How do you prefer it?

Thanks and regards

 

[lexvil]

I just put it together and check it.

 

[Geo7]

Good question. The advice I heard is to install the valve lifter, diaphragm, and IP spring before installing the HP seat. As long as you don't screw in the spring pad too far, you should be fine. The thing to avoid is HP seat touching the crown (should not happen when unpressurized). So, basically, like Lexvil said...

 

[MARK74]

Thanks for your contribution, the funny thing is that when reading manuals from different brands, they contradict each other, some recommend mounting the HP side first and checking for leaks (which seems fine to me)
others however say to mount the LP side first.
Thank you both and I look forward to more opinions please, I always like to listen to continue learning.
After 40 years repairing regulators I still consider myself an apprentice.

Good weekend

 

[rsingler]

The reason for the difference in assembly order is a problem called "concentricity".
If you assemble the HP side first, most brands have a HP seat that does not fill the diameter of the bore, in order that airflow around the poppet is not obstructed. If the poppet is slightly off center when the HP seat carrier is screwed in, the seat face will develop a circle of indentation that is different from the circle that is formed after the pin is inserted from the other side.
Where those two circles overlap may cause a slight leak.
The Scubapro poppet is much wider, and centers itself perfectly. Air flow is preserved by the flutes cut into the top of the seat. Assembling it first allows one to confirm the seal of the valve before the diaphragm is clamped down.

In contrast, all the other designs center their poppet with the lift pin, which necessitates that the diaphragm go on first, holding the HP seat away from the volcano until the first pressurization.

 

[MARK74]

The reason for the difference in assembly order is a problem called "concentricity".
If you assemble the HP side first, most brands have a HP seat that does not fill the diameter of the bore, in order that airflow around the poppet is not obstructed. If the poppet is slightly off center when the HP seat carrier is screwed in, the seat face will develop a circle of indentation that is different from the circle that is formed after the pin is inserted from the other side.
Where those two circles overlap may cause a slight leak.
The Scubapro poppet is much wider, and centers itself perfectly. Air flow is preserved by the flutes cut into the top of the seat. Assembling it first allows one to confirm the seal of the valve before the diaphragm is clamped down.

In contrast, all the other designs center their poppet with the lift pin, which necessitates that the diaphragm go on first, holding the HP seat away from the volcano until the first pressurization.

Excellent contribution, thank you very much mate.

 

[buddhasummer]

The reason for the difference in assembly order is a problem called "concentricity".
If you assemble the HP side first, most brands have a HP seat that does not fill the diameter of the bore, in order that airflow around the poppet is not obstructed. If the poppet is slightly off center when the HP seat carrier is screwed in, the seat face will develop a circle of indentation that is different from the circle that is formed after the pin is inserted from the other side.
Where those two circles overlap may cause a slight leak.
The Scubapro poppet is much wider, and centers itself perfectly. Air flow is preserved by the flutes cut into the top of the seat. Assembling it first allows one to confirm the seal of the valve before the diaphragm is clamped down.

In contrast, all the other designs center their poppet with the lift pin, which necessitates that the diaphragm go on first, holding the HP seat away from the volcano until the first pressurization.

The good Dr does it again.

I'm in awe Rob, big brain

 

[buddhasummer]

I assemble as per respective manuals.

Never gave it much thought, small brain. After reading @rsingler post it now makes sense.