Shearwater Swift transmitter —> do I need a valve for a hose mount?

[OMyMyOHellYes]

Why bother? The transmitter just needs to be hand tight. If you have to swap it out for a hose/SPG(unlikely) all you need is a wrench to snug it down.

Exactly. A local LDS tried to sell me one so I could remove my transmitter. I asked the question that always seems to stop the upsale fudgery: "Why? What about it will it make it $70 easier, or better, than just unscrewing the Xmitter? I do that by hand and if I want to replace it with a hose and gauge, I do that by hand tight too, with a tiny nudge from a wrench I keep handy." They were dumbfounded and mumbled something along the lines of "well .... it's cool". Not really - just costs me money and adds an inch and a half of bulk and another potential failure point to my rig.

 

[ReefHound]

We had transmitters directly on the HP port for years, but recently added 6” hoses (which is when you need the spool). Stopped me from wincing every time I watched someone pick up the rig by the transmitter.

I've thought about that many times but still not sure I want to do it. In practice, I'm usually the one moving my rig and when I've been on dive boats in Cozumel/Roatan/etc. the DMs have been, at least the times I was watching, careful about not lifting by it or hoses. The downside of using a hose is more failure points.

 

[VsubT]

Why bother? The transmitter just needs to be hand tight. If you have to swap it out for a hose/SPG(unlikely) all you need is a wrench to snug it down.

I use the DGX HP quick disconnects on a short hose with a single Shearwater Swift transmitter to switch it quickly between my single tank and doubles reg sets. Very quick to switch between them, and it makes it super easy to pull the transmitter off when packing regs in checked bags. I'm comfortable switching hoses & plugging ports with tools, but this option is a lot quicker if you're diving regularly and switching configurations often.

Lance

 

[Moonhowler]

What about nitrox? I'm a noob, replacing a bad HP hose for my Scubapro SPG. The air spool is the straight bullet type. The only straight spools I can find for it have the Buna N O-rings and I've read that you need the Viton if you're using nitrox. The only spools I see with the Viton rings have the T, or shoulder, or flange (whatever you call it). Is it true that you shouldn't use the Buna N O-rings with nitrox?

 

[Belzelbub]

The only spools I see with the Viton rings have the T, or shoulder, or flange (whatever you call it). Is it true that you shouldn't use the Buna N O-rings with nitrox?

Generally, most regulators are fine for up to 40%. Lots of Buna N on hoses and the like. The tank and associated O-rings on the tank are generally the big concern, and that has to do more with how the tank is filled with Nitrox versus the actual mix. My tanks all get O2 cleaned as some of the shops I use to fill use partial pressure blending. As that involves filling with 100% O2, it's of greater concern than shops that use banked Nitrox or other methods.

 

[Bloody Marvelous]

I keep mine on a short Scubapro 3 inch hose that came with a HP spool. To me, having it on a short hose has a couple of advantages:

1. Little risk it gets mistaken for a tank valve so they don't try to lift the tank by the transmitter.
2. If the transmitter gets bumped, the hose allows it to move out of the way.
3. It may improve the connectivity with the dive computer.

As for HP spools, I had a hard time finding some as well. I had been to several dive stores that were either out, or didn't sell them in the first place. I also couldn't find any webshop that sold any in my country, and those outside that did charged like $15 or $20 for one plus shipping, which I thought was ridiculous. When I finally found a store that had them in stock, I bought a couple to put in my SADK.

As for Nitrox, you don't really need to worry too much about the transmitter or SPG because gas doesn't flow through it. It just builds up pressure, and if you open your valve slowly there's no risk of igniting anything, especially up to 40%. If you're going to use one on pure oxygen I'd have it O2 cleaned.

 

[Pearlman]

What bullsh!t, you would only need an air spool DGX Air Spool w/ Viton O-Rings for SPG Swivel

Why do you think you need to connect your transmitter with a hose rather than directly?

That’s not the one. It’s only for SPGs - the center flange is for 360 deg rotating swivels as we are prone to turning the SPG into our face in operation. The ones supplied with my Sunnto transmitters come like the ones in the attached pic ( the double notch side is meant to be oriented in a certain way - it is unidirectional ). One is for the QD and the other for the hose IIRC. Sunnto calls them flow-restrictors rather than spool. I’m guessing that the OP likely misplaced the ones supplied by manufacturer as soon as the package was opened? Or the package was not sealed and it was removed before delivery.

Exactly. A local LDS tried to sell me one so I could remove my transmitter. I asked the question that always seems to stop the upsale fudgery: "Why? What about it will it make it $70 easier, or better, than just unscrewing the Xmitter?

I use it because on boats that change tanks after every dive, the boat crew (especially in S.E Asia) is very likely to lift your gear off the tank holding the tank pod like a handle (or even carry it with the weight of the tank strapped on to move your gear - like changing assigned seat location in a boat while you are on the upper deck ). And I dont want the threading on my costly regs and pod damaged. I usually always setup my gear, but it does happen that you’ve just surfaced from a dive and while you are making your cuppa tea or grabbing a biscuit or simply sunbathing on the deck to warm up, an efficient boat crew has already swapped your tanks while your back is turned to them.

Only a few dive boats have in-place tank-refills with a powerful compressor in the belly of the boat where your BP/W and Scuba gear basically sits on the tank for the entire diving week including overnights with nobody ever touching your gear. For the other cases, I use the 6” hose to make sure it does not look like a weight bearing handle. I also don’t thread the metal QD directly into the reg for precisely this reason.

This is what my transmitter setup looks like. The QD is there so that I can carry the transmitter back with me to hotel room. My DC is always on my wrist till I shower and rinse back in the hotel and the tank pod goes in my dry bag. On my last dive vacation, all of my gear was left on the dive boat overnight for one week at a time. But for peace of mind I like to keep the tank pod and DC with me always - easily pocketable in a worst case scenario.

 

[Endler's]

The ones supplied with my Sunnto transmitters

Suunto air spools are special flow restrictors. This is Sunnto's fix to keep their transmitters from bursting.
Suunto Recalls ALL Computer Transmitters and PODs.

Suunto also get to sell their spools for $30.

Sadly, Garmin also opted for proprietary air spools: Garmin T1 Transmitter Air Spool and Flow Restrictor Kit (and costs $10 more than Suunto).

Those of us using Aqualung or Swift transmitters, can use the $1.50 ones from DGX.

 

[Moonhowler]

Generally, most regulators are fine for up to 40%. Lots of Buna N on hoses and the like. The tank and associated O-rings on the tank are generally the big concern, and that has to do more with how the tank is filled with Nitrox versus the actual mix. My tanks all get O2 cleaned as some of the shops I use to fill use partial pressure blending. As that involves filling with 100% O2, it's of greater concern than shops that use banked Nitrox or other methods.

Thanks. I've learned about the "40% rule" for components at intermediate pressure, but nevertheless, on the descriptions of the two types of spools, the one with the shoulder that has the Viton o-rings usually has the blurb saying something about being safe for Nitrox. Also, I've seen three or four videos now on how to change the spool for an SPG, and they all mention using "oxygen safe" grease. So I keep wondering if I need to hunt down Viton o-rings and buy the ridiculously expensive O2 safe grease just to put in a new air spool. (Both my Scubapro and Subgear SPGs don't work with the shouldered spool I have - they won't swivel).

 

[Endler's]

Shearwater may end up doing same thing:
Swift Transmitters - lesson learned
Shearwater transmitter failure
New Shearwater AI transmitter - the Swift
But I doubt they would charge $30 - $40 for the kit.