Um... shouldn't an SPG go to a high pressure port?

[lavachickie]

Dumb question of the night... a friend (for whatever reason) is lacking an SPG. I get a loaner from my LDS, and it's pretty ancient but... it connects to a low pressure port. WTF? I thought this would have to go to a high pressure port!? What's up with this?

 

[Scott L]

Wrong hose prehaps...

 

[JBRES1]

Hi,

Yes the pressure gauge goes to a igh pressure port.
Does it fit on an lp port ?
On most regs the threads are not the same for lp and hp ports.

Jim breslin

 

[lavachickie]

Very bizarre, then. I just wanted to make sure *I* wasn't crazy. I've always used consoles, not a standalone SPG so just wanted to make sure there wasn't something unusual. *sigh*

 

[Delta_P]

Yep, it's ancient, from back when all ports used the same thread, at least on USD regulators.

 

[lavachickie]

Thanks, Delta_P, that s'plains it. Cuz it IS ooooooold.

 

[mikediveguy]

tell lds, ask for an adapter so it can go in correct hp port lol

 

[aquaregia]

Yeah, older regulators didn't use the bigger diameter for the HP. All my Mk5s are like that.

 

[herman]

Up until the late 60s or early 70s both LP and HP ports on regs had the same 3/8x24 threads and so putting the wrong hose in the wrong port was possible. Someone got the bright idea to change the standard port size to 7/16 to prevent this from happening and that has become the "standard" size for scuba HP ports ever since. While talking about port sizes, some dummy also decided that a 1/2 port would be better for the LP hoses. Useless idea but you will find some regs with 1/2 LP ports as well as 3/8 ports. I think Dacor started it but I have seen them on Dacors, Apeks and USD/Aqualung. There are port adapters available to convert 3/8 to 7/16, 7/16 to 3/8 and 1/2 to 3/8. It's not a bad idea to keep one of each on hand if you swap regs and equipment around much.

 

[scubafanatic]

....interesting! I've been diving since 2001, am something of a scuba 'gearhead', even have some vintage (collectable twinhose regs) and I'd never heard of this 'issue'! Thanks for sharing!