Airflow testing

[Open Ocean Diver]

Hello ScubaBoard... Setting up my home reg test bench, have just about everything I need, and was wondering if I should add flow testing capabilities? I was hoping to get some feedback on the pros and the cons, is dynamic testing worth wild, and does it help with fine-tuning your cracking effort to a different level of precision?

thanks,

Kevin

 

[rsingler]

It doesn't help with setting cracking effort. It's an interesting bit of data that shows whether your reg had just the right amount of Venturi assist, or shifts into freeflow at high flows (and maybe at depth).

It was useful in the old days when the G250 required the tech to set the angle of the Venturi vane. Now that it's user adjustable, most divers wouldn't even understand what you told them if you instructed them to dive with it cracked "slightly less than full Dive". In this pic you can see a G250 with 1.2" inspiratory resistance at 4 cu ft/min, and some unreadable dynamic IP off that Mk 10. Like I say, interesting, especially when comparing with other second stages, but not really value added.

In a home shop, it uses huge amounts of air, so if you don't have unlimited access, you'll quickly stop using it. In the pic, I abandoned using the Venturi flow generator (the disconnected 1/8" tubing next to the rotameter, instead inserting a small shop vac to generate flow at the top. Cut my air use by 2/3.

If you're a geek, it's fun to build. Buy a rotameter and put the rest together yourself. Buying a flow bench from Scubatools is very hard for me to justify.

 

[Open Ocean Diver]

Thanks for your reply, very helpful and you saved me $1000. I was just thinking with a consistent vacuum it would be easier to fine-tune the cracking effort. If I build one I’m not sure about the Venturi pump but if I can figure that part out and then just use a small portable air compressor that should help with the volume of air issue. Thanks again very helpful reply.

Just a sidenote I rebuilt my first D 400 last night, wow you weren’t kidding it’s sure breathes easy. I bought a service kit for it but it didn’t come with a spring pad mine was missing, or O-rings for the housing, I used some O-rings out of my standard O-ring kit dimensions were the same material was different couldn’t get it to stop leaking so I had to go back to the original and everything sealed right up. Looking forward to trying it in the pool.

kevin

 

[grf88]

This might be of interest:
Regulator test rig you don't need to suck.

 

[Open Ocean Diver]

This might be of interest:
Regulator test rig you don't need to suck.

I like it found the parts. Should 6 LPM for the pump be enough?

thanks great idea.

 

[grf88]

I like it found the parts. Should 6 LPM for the pump be enough?

thanks great idea.

I am not sure, I am thinking about building one and thought that if it was not enough you could add a reservoir as you don't need much pressure differential. Maybe a 5 gallon bucket or something.