SPG or not

[Belzelbub]

Still a good idea. Most dive charters are going to check your valve before you splash. If you cut the valve back a quarter turn the person who turns it knows it's definitely on when it twists open that last little bit. If it's all the way open they really gotta give it a twist to make sure it's not firmly closed. Makes their job easier and repetitive attempts to twist an already valve open even more isn't going to do it any good.

Doesn’t sound like a good idea to me. I prefer it to be fully on or fully off. No chance in making a mistake then. If it’s somewhere in between, it could be mostly on or mostly off. If it’s mostly off, it will turn either direction when the crew checks. Breathes fine until higher flow needed at depth.

 

[LI-er]

Doesn’t sound like a good idea to me. I prefer it to be fully on or fully off. No chance in making a mistake then. If it’s somewhere in between, it could be mostly on or mostly off. If it’s mostly off, it will turn either direction when the crew checks. Breathes fine until higher flow needed at depth.

I didn't say it should be turned mostly off. A quarter turn off won't make any difference unless perhaps if the diver has severe COPD.

 

[jellycatsdad]

I still have an SPG on my setup though I’m using a Shearwater Swift.

 

[Valerii Vakshul]

comprehensive check of my gear +2teriс

 

[Belzelbub]

I didn't say it should be turned mostly off. A quarter turn off won't make any difference unless perhaps if the diver has severe COPD.

I know you didn’t say it, but that’s what happens in some cases. When it’s not fully on or off, it can be anywhere in between. The valve can turn in both directions. When fully on or fully off, it can only turn one direction.

 

[LI-er]

I know you didn’t say it, but that’s what happens in some cases. When it’s not fully on or off, it can be anywhere in between. The valve can turn in both directions. When fully on or fully off, it can only turn one direction.

The way I see it, if it's a quarter turn from full on, when the crew goes to check it, they're only going to turn it one way, and that's always going to be counter clockwise. It will turn a bit which confirms that it's open. If the crew twists it counterclockwise and it's already full on, they can't be sure it's open unless they twist really hard whereas that little bit of a turn to full on doesn't require a hard twist.

But I'm getting repetitive. Either my point makes sense or it doesn't.

 

[USdiver1]

1970s explanations

The valve quarter turn from full was always explained to me as a precaution against hitting the valve wheel against a hard object [wreck / cave /etc.] so that it wouldn't crack or over extend [strip] past its set limit. Several manufactures used bakelite plastic valve handles which were somewhat brittle and could get damaged.

The SPG faceplate [front] / relief valve [back] positioning away from one's face was to protect from the plexiglass / tempured glass faceplate or air from the relief valve damaging one's eyes in the event of a failure.

PS when not diving my DH and J-valve, I use a rig that incorporates both SPG and AI transmitter.

 

[Bigbella]

SPG or not?​

Yes . . .