How can I tell if my rig is an upstream regulator?

[Whale Whisperer]

I have the Atomic B2 regulator, and I'm wondering if my reg is upstream or downstream design (Hearing unfavorable things about upstream). Looking at the technical specs, Atomic says the first stage is a "Balanced, flow-through piston" and the reg hose is a standard hose.

I'm new to the sport and gear, and my concern is what would happen if this reg fails. Will it cut off my airsupply?

 

[The Kraken]

Downstream.
If it fails, it will fail in the open mode and you'll get a free flowing regulator.

the Kraken

 

[Falco]

The majority of regulators in production today are downstream. Most of the well known compagnies such as Atomic, Apex, Scubapro, Sherwood or Zeagle produce only downstream regulators. The only well known compagny who's reg line up is composed majoritarily of upstream regs is Poseidon.

 

[Mr.X]

The majority of regulators in production today are downstream. Most of the well known compagnies such as Atomic, Apex, Scubapro, Sherwood or Zeagle produce only downstream regulators. The only well known compagny who's reg line up is composed majoritarily of upstream regs is Poseidon.

I wanted to add that you may occasionally find the odd Oceanic omega reg. and didn't Scubapro produce a servo valve reg. sometime in the 80's? Sherwood sold an early Maximus which was a Poseidon 2nd stage.

 

[mdb]

I wanted to add that you may occasionally find the odd Oceanic omega reg. and didn't Scubapro produce a servo valve reg. sometime in the 80's? Sherwood sold an early Maximus which was a Poseidon 2nd stage.

Mr X: Don't forget TEKNA, basically, a knock off SP Mark V 1st stage and Poseidon style second stage; with the usual TEKNA QC problems.

 

[Mr.X]

Mr X: Don't forget TEKNA, basically, a knock off SP Mark V 1st stage and Poseidon style second stage; with the usual TEKNA QC problems.

Thank you! I had forgotten all about that dinosaur. I remember a pal won one in a raffle...I do remember that it went funny real fast.


I'll make a list - a short list:

Poseidon
Oceanic Omega
Tekna
Sherwood Ultima with an Odin second stage

and possibly a Scubapro from the 80's??? I just forget the specs. but it had a strange second stage with a pre-dive switch built in. X

 

[Sherwood SCUBA rep.]

I wanted to add that you may occasionally find the odd Oceanic omega reg. and didn't Scubapro produce a servo valve reg. sometime in the 80's? Sherwood sold an early Maximus which was a Poseidon 2nd stage.

The reg in question was a Sherwood Ultama not the Maximus.

 

[Mr.X]

The reg in question was a Sherwood Ultama not the Maximus.

Thanks. I stand corrected. What's funny is that I have the Sherwood repair bulletin sitting somewhere in my office as future reading material. I loved the big first stage that went with this hybrid. Cheers. X

 

[redacted]

Your 2nd stage is clearly a downstream valve. That is, the pressure on the valve is pushing it open. With an upstream valve, the pressure is pushing it closed. Your first stage is a balanced piston design so the pressure coming into it is not pushing the valve open or closed. Rather the pressure going out of the first stage is pushing the valve closed so I think of it as a midstream design. Unbalanced piston 1st stages are downstream design. Diaphram 1st are upstream designs. But all first stages tend to fail open

Upstream 2nds may fail in a closed mode but an overpressure valve is used to keep it from getting too messy and bursting hoses. If a shop is badmouthing upstream design 2nd stages, that usually just means they are not a Poseidon dealer.

 

[redacted]

I thought about this a bit more overnight. I suspect that I can induce a failure in any regulator setup, regardless of design, that will result in no gas available to the diver although it is available in the tank. There is little need to get excited over upstream vs downstream designs. Unless, of course, you happen to be selling one or the other.