Scubapro c300

[Tanks A Lot]

What was the difference between the C300 and the C350? I remember there was some sort of problem with the C300 which was supposedly fixed in the C350.

The only difference is in the purge cover.

The C300 has one piece, which incorporates the retaining ring and the purge cover. The C350 has a flexible purge cover, which is held in place by a separate retaining ring.

The C300 cover is the same as the C200. In general I do not think one piece flexible purge covers are a good way to engineer these. The balance between flexibility, to allow purging, rigidness, to withstand impact and durability is a very hard balance to strike right. Especially durability can suffer over time if the other two are met just right and the material becomes brittle after a while. I do not recall if this was indeed a problem on the C200 and C300.

The C350 and C370 cover have a soft purge cover, which is encased by a hard retaining ring. Unfortunately they had the silly idea of putting these shiny metal stripes onto the retainer. They have no functionality at all and inevitably work themselves lose. I would have preferred a simpler, more functional design there.

Otherwise they are the exact same unbalanced second stage. The C370 would be the "upgraded" balanced version. I do like the C200 to C350 poppet design. Their design is such a genius way of routing the airflow while still using a barrel and a diver adjustment knob. While not balanced, I really think these are top notch second stages, leaving my small gripes from above aside.

 

[ams511]

The only difference is in the purge cover.

The C300 has one piece, which incorporates the retaining ring and the purge cover. The C350 has a flexible purge cover, which is held in place by a separate retaining ring.

View attachment 816083
The C300 cover is the same as the C200. In general I do not think one piece flexible purge covers are a good way to engineer these. The balance between flexibility, to allow purging, rigidness, to withstand impact and durability is a very hard balance to strike right. Especially durability can suffer over time if the other two are met just right and the material becomes brittle after a while. I do not recall if this was indeed a problem on the C200 and C300.

View attachment 816084
The C350 and C370 cover have a soft purge cover, which is encased by a hard retaining ring. Unfortunately they had the silly idea of putting these shiny metal stripes onto the retainer. They have no functionality at all and inevitably work themselves lose. I would have preferred a simpler, more functional design there.

Otherwise they are the exact same unbalanced second stage. The C370 would be the "upgraded" balanced version. I do like the C200 to C350 poppet design. Their design is such a genius way of routing the airflow while still using a barrel and a diver adjustment knob. While not balanced, I really think these are top notch second stages, leaving my small gripes from above aside.

Thank you for your in-depth explanation. I have the Subgear variant of this regulator. I think it was called the SG-30 or something like that.

 

[Tanks A Lot]

Yes, the C-Family from ScubaPro would map more or less as follows:

SG10 -> C200 - With the better purge cover from the C350 and up. No silly metal stripes...
SG30 -> Mix between C300 & C350 - Can you believe that ScubaPro left those silly metal stripes of the SG30 & SG10, I wish they would have done on the rest as well...
SG50 -> C350 - Basically the SG30, with the "upgraded" metal stripes and a jam-nut sleeve - Nothing but added optics, the SG30 is objectively better)

If you have an SG30 you have one of my favorite unbalanced second stages.