Nitrox Stik Flowmeter recommendation.

[John Pham]

I'm building a Nitrox Stik using Max Air 35 gas compressor and having a hard time deciding which reliable flowmeter to get, what should I look for in a flowmeter and your recommendation. Thanks

 

[rddvet]

Buy a Dwyer. Very accurate and reliable. A great way to do it is attach a solenoid between the oxygen reg and the flow meter. Wire it to the compressor to shut the solenoid when the compressor is off

 

[John Pham]

Buy a Dwyer. Very accurate and reliable. A great way to do it is attach a solenoid between the oxygen reg and the flow meter. Wire it to the compressor to shut the solenoid when the compressor is off

Thanks, what lpm should I be looking at?

 

[NAM001]

Thanks, what lpm should I be looking at?

A 40% mix uses 1/4 O2. so min 1/4th of the compressor capacity. If 6 cuft then >1.5 cuft and that is apx 30 ltr per cuft or >45 ltr/min. or 0-3600 liters per hour.,,,,, in cuft / hour would be about 100

DWYER NAT. GAS RATE-MASTER FLOW METER | eBay

Dwyer instruments Flow Meter | eBay

RMB-54 0-200 SCFH Dwyer Flow Meter | eBay

there are a lot more out there

 

[John Pham]

A 40% mix uses 1/4 O2. so min 1/4th of the compressor capacity. If 6 cuft then >1.5 cuft and that is apx 30 ltr per cuft or >45 ltr/min. or 0-3600 liters per hour.,,,,, in cuft / hour would be about 100

DWYER NAT. GAS RATE-MASTER FLOW METER | eBay

Dwyer instruments Flow Meter | eBay

RMB-54 0-200 SCFH Dwyer Flow Meter | eBay

there are a lot more out there

Awesome, Thanks You =)

 

[clownfishsydney]

I just used a welding oxygen regulator and modified the outlet to throttle the flow a bit. I can then dial up the nitrox mix I want to within 0.25%. All it took was a little experimentation at the start to work out what % I got for a few different psi readings. Then an Excel spreadsheet to work out what each 50 psi increment gave. Easy.

 

[Wookie]

Buy a Dwyer. Very accurate and reliable. A great way to do it is attach a solenoid between the oxygen reg and the flow meter. Wire it to the compressor to shut the solenoid when the compressor is off

This is exactly what I have. Set up for my 8 CFM Mako. I regulate the O2 down to 10 PSI with a regular welding reg and have a solenoid wired into the time delay on the compressor so the compressor is up to speed and oil pressure is good. 10 seconds after the compressor starts, flow starts. 56 lpm for 32%, 66 lpm for 36%.

I just used a welding oxygen regulator and modified the outlet to throttle the flow a bit. I can then dial up the nitrox mix I want to within 0.25%. All it took was a little experimentation at the start to work out what % I got for a few different psi readings. Then an Excel spreadsheet to work out what each 50 psi increment gave. Easy.

If I were doing this, I'd use an argon regulator and rebuild it with viton o-rings, with a flowmeter built in. You can get them easily here.

 

[wwunder]

for my Bauer Utilus 3.5 CFM i just use a medical O2 regulator with 15 lpm range. Doesn't quite get to 40%, but I mostly stick with 32% for CB and would switch over to PP for deco mixes.

 

[rjack321]

You can get a new 0-15 lpm O2 reg on ebay for $25. At 100lpm flow (which only actually happens on start up under no load) you need 14 lpm for 32%.

Autoshutoffs and such add-ons are nice but the max air 35 is not continuous duty, so you need to watch and attend it anyway. Save your money.

 

[Wookie]

You can get a new 0-15 lpm O2 reg on ebay for $25. At 100lpm flow (which only actually happens on start up under no load) you need 14 lpm for 32%.

Autoshutoffs and such add-ons are nice but the max air 35 is not continuous duty, so you need to watch and attend it anyway. Save your money.

Except for that whole exploding compressor thing when it auto shut offs and the first stage fills with O2 and it autostarts when you put the next fill on, I wholeheartedly agree.