Question on old Scubapro spg.

[ScubaLawyer]

Found an old Scubapro SPG. Needs a hose so took off existing one and see this little brass nipple/socket setup as opposed to the standard o-ring sealed insert. Don't believe the female hose end is currently available.  What to do? Anyone have a schematic for these puppys? Haven't taken the nipple end out of the housing - not sure I want to. Or is the other end of the nipple piece a standard o-ring sealed end? What can I do to get it serviceable again? Thanks. Mark

[couv]

Mark,

I believe the inside of a standard hp hose is actually a flared fitting, so the first thing I would try is simply hooking up a hp hose with no spool and slowly pressurize it. Flared fittings with metal on metal seals are common in several industries. Do me a favor and tie the gauge and hose down please.

[luis]

The old HP hoses were standard flare fitting. Some of them may still have the conical female receiving fitting, but a lot (if not most) of the newer hoses are now flat inside and will not accept the male flare fitting. You just have to look inside until you find one that fits.

There are probably plenty of vintage HP hoses that are still in good shape and I would not hesitate about using them.

As an alternative, you can clean the inside of that male fitting with a Q-tip and use a modern O-ring adapter fitting in it. That was the only conversion done to the early gauges when it was felt that a swivel would be convenient.


I would not try to take apart the gauge. It will not gain you anything and you could break the connection to the bourdon tube inside.

Good luck

[ScubaLawyer]

Couv, Luis,

Thanks for the insight. I must have an old HP hose around here somewhere. I'll futz around with it some more. Mark

[couv]

I'm pretty sure new hp hoses have flared fittings-probably 37 degree (AN 37) or SAE 45. Way back when Christ was a corporal, when a fitting suffered an imperfection on one component or the other, a copper cone washer was installed between the two.

[captain]

I believe it is an AN 3 37 degree flare fitting, same as the old Sea Vue gauge I have. A hose supplier should be able to make one in stainless steel. It's what I have on my Sea Vue. It won't swivel so you have to position it how you want and then tighten the connection.

[couv]

Captain is on to something there.
A standard hp hose fitting is a female 7/16-20 which would be an AN #4
Older hoses were 3/8-24 which would be an AN#3

Does the old cut off hose thread onto a standard hp port plug or a lp plug? It wont seal of course because one is a straight while the other is a flare, but at least we can size it. After you've determined the size, again I suggest a copper cone washer https://secoseals.com/ from a hydraulic supply store.

[ScubaLawyer]

Captain is on to something there.
A standard hp hose fitting is a female 7/16-20 which would be an AN #4
Older hoses were 3/8-24? which would be an AN#3

Does the old cut off hose thread onto a standard hp port plug or a lp plug? It wont seal of course because one is a straight while the other is a flare, but at least we can size it. After you've determined the size, again I suggest a copper cone washer https://secoseals.com/ from a hydraulic supply store.

Hi Couv,

Good question, I will check tonight when I get home. I'm going to look through my pile of old hoses tonight to see what I have as well. Hate to do all this and have the gauge not work but that's half the fun of working on this old dangerous dive crap.

[SnarkIII]

Mark - I recently picked up a box of old SPG's. In the box was one just like yours, and also a Sportsways Sea-vue. These two gauges appear from the outside to be identical. There is a schematic for the Sea-vue in the VDH manuals section.

[ScubaLawyer]

Mark - I recently picked up a box of old SPG's. In the box was one just like yours, and also a Sportsways Sea-vue. These two gauges appear from the outside to be identical. There is a schematic for the Sea-vue in the VDH manuals section.

Thanks!

[captain]

I wlooked at my Sea Vue gauge, it is on a standard spg hose. the only difference is you can't use the spool that allows the gauge to swivel because of the male flare on the gauge.
It might be possible to file away the male flare cone on the gauge and use a swivel spool .

[ScubaLawyer]

I wlooked at my Sea Vue gauge, it is on a standard spg hose. the only difference is you can't use the spool that allows the gauge to swivel because of the male flare on the gauge.
It might be possible to file away the male flare cone on the gauge and use a swivel spool .

Looking in my parts bin I found a modern metal-braded standard spg hose that looks like it will work. The thread size is identical to the one that was on my gauge but the hole in the female portion is just slightly larger diameter. In the meantime i looked at the schematic of the Sea Vue gauge and it looks like there are at least two o-rings (one under the screw-down cover, and one on the back of the gauge). Can't imagine those o-rings still being water tight. Might try to use a strap wrench to remove the screw-down cover and replace that o-ring. Hate to open it up but i've had several vintage gauges fill with water recently so might want to take a safer approach. Just afraid of having the bourdon tube damaged. We'll see. M

[couv]

I'm looking forward to the update and pictures. Hopefully, the glass o-ring will be a common size.

[antique diver]

If you are going to open the front cover you might as well also take the back nut off and carefully remove the whole works from the case. There should be an oring back there that needs replacing as bad as the front one. You can do it. It's much simpler than a regulator.

Just my opinion, but I would just skip worrying about a swivel and not modify the male JIC end at the gauge. If reading the gauge at an odd angle bothers you the angle can be adjusted at the hose connection to be fairly straight in your field of view while you have the reg mounted in place and rig on your back. I may be strange, but to me upside down looks pretty much same as right side up... maybe because I'm left handed.

[ScubaLawyer]

I'm looking forward to the update and pictures. Hopefully, the glass o-ring will be a common size.

Finally got the spg apart. The main dial o-ring is toast but I'll take a look at the hardware store and see what I can improvise.

The rear o-ring is also bad, and interestingly, there appears to be another groove for a 2nd o-ring but none was present. The mechanism itself looks great. I'll post further once I find the proper size o-rings. Mark