Scubapro 156 and 108 first stage advice.

[Tr4lover]

Just finished up my new 156 and 108. The 156 has the updated s poppet also. Looking forward to diving these soon.

I went ahead and bought a used mk17 I'm going to go through. Planning on using this as the 1st stage. Any thoughts?

 

[scrane]

Sounds good. Have fun.

 

[p_kos]

Very nice! Only thought is once you service the MK17 tune the 108 at low tank pressure (300-500 psi) when the IP is highest since it’s an unbalanced second stage. The MK17 is “balanced” but the IP can still be around 10 psi higher at low pressure.

 

[Tr4lover]

Very nice! Only thought is once you service the MK17 tune the 108 at low tank pressure (300-500 psi) when the IP is highest since it’s an unbalanced second stage. The MK17 is “balanced” but the IP can still be around 10 psi higher at

 

[Tr4lover]

I do not believe this 108 can be tuned. Other than that micro nylon nut.

 

[p_kos]

I do not believe this 108 can be tuned. Other than that micro nylon nut.

Yes, you set the cracking pressure via the nut. The 108HP also had a screw in orifice which made it easier. Or leave it alone and adjust the MK17 IP accordingly (at low tank pressure).

 

[Open Ocean Diver]

If your 108 doesn’t have an orifice, I think you have the rubber covers mixed up.

 

[p_kos]

If your 108 doesn’t have an orifice, I think you have the rubber covers mixed up.

Yup, good eye.

 

[Tr4lover]

Yes, you set the cracking pressure via the nut. The 108HP also had a screw in orifice which made it easier. Or leave it alone and adjust the MK17 IP accordingly (at low tank pressure).

This unit has a fixed orifice unfortunately. Thanks for the knowledge. The case also uses the dual exhaust diaphragms. But I've been told a single works just fine. Breathing is much harder with both diaphragms installed.

 

[Tr4lover]

If your 108 doesn’t have an orifice, I think you have the rubber covers mixed up.

It is very possible. I am having to replace the case ring screws I will definitely take a look again. I remember the covers where built different.