Quick question.

[tomhooper]

I recently purchased a US Divers primary and secondary regulator. It did not come with a set of gauges. I have several spares. It appears that the port on the primary is probably a 3/8" and the hose fitting is 1/4". I am attaching the gauge to a HP port on the primary but now am doubting myself. Someone help me. If this is correct, can I use a bushing/converter to hook up the gauges? Thanks for any help.

Tom Hooper
Gary, Texas

 

[herman]

There are 2 standards for the HP port size....and there are also 2 standards for LP ports as well. The old HP standard is 3/8x24, same as most LP ports. The modern standard is 7/16x20, depending on the age of the reg it could have either one. The 2 standards for LP ports are 3/8x24 (most common) and 1/2x20, USD regs have had both in the past so you could have either or both.
Which port is HP and which is LP is easy to determine. If you look inside the hole in the first stage, a HP port will have a very tiny hole in the reg, it almost looks like a blind port. The LP ports will have a much larger opening, in the 1/8 inch range.

While on the subject, the correct terms are first stage (hooks to tank) and second stage. Primary and secondary refer to the use of the second stages, primary being the main one you use and secondary being your alternate/octo.

Welcome to the board.

 

[tomhooper]

Wasn't aware of the terminology mistake. Been calling in wrong for 20 plus years. Anyway, the first stage has HP stamped next to the high pressure ports. Makes it idiot proof which as I get older I find I need more and more. I am correct in that the gauges connect to the HP port right? Also can a bushing be used?

 

[Scared Silly]

Yes, a bushing can be used and yes the gauges go to the hp port.

Any dive shop that has been in business for a long time will have the 7/16 -> 3/8 bushing.

 

[tomhooper]

Thanks.

 

[Shftrdog]

All first stages have the same ports, high pressure and low pressure. Gauges and computers can only go in the HP ports. You can identify these becasue they are the larger of the two ports. If it fits then it is the correct port, the gauges will not be able to fit in anything but the HP port.

 

[herman]

All first stages have the same ports, high pressure and low pressure. Gauges and computers can only go in the HP ports. You can identify these becasue they are the larger of the two ports. If it fits then it is the correct port, the gauges will not be able to fit in anything but the HP port.

I don't mean to me rude but that is just plain wrong and as a dive shop you should know better.
Up until the mid to late 60s both the HP and LP ports were 3/8x24 and it was quite possible to put a LP hose into a HP port....with violent results I might add, which is the main reason the change was made. In addition, there was a trend for a while to put 1/2x20 LP ports on some regs. Dacor did it as well as USD, there may be others but I am positive of those 2, I own an example of each. While it is pretty much the case on regs from the late 60s (for HP) to today that the HP port will be 7/16x20, you can not make a blanket statement about the port size without knowing exactly which reg you are discussing, same goes for the LP ports.

 

[Couv]

All first stages have the same ports, high pressure and low pressure. Gauges and computers can only go in the HP ports. You can identify these becasue they are the larger of the two ports. If it fits then it is the correct port, the gauges will not be able to fit in anything but the HP port.

Not so fast there young fella. From your profile, I see that you probably work in a dive shop but have been around for less than 10 years. The OP very well may have an older first stage regulator that has a hp port that will accept a 3/8 lp hose.

Edit: Herman was typing at the same time and pretty well explained the HP/LP issue.

To the OP, there are adapters available to convert your hoses and ports:

Adapters and Special Fittings - Dive Gear Express

you can also get a 3/8 hp hose from Vintage Double Hose:

http://www.vintagedoublehose.com/store/index.php?main_page=product_info&cPath=48&products_id=605

 

[Brendon]

All first stages have the same ports, high pressure and low pressure. Gauges and computers can only go in the HP ports. You can identify these becasue they are the larger of the two ports. If it fits then it is the correct port, the gauges will not be able to fit in anything but the HP port.

Im not sure which is more absurd...Your reply to this comment or the one on another thread where you said all scuba equipement is made from the same manufacturer... I think you should just refrain from offering "instructor" or "experianced diver" grade questions... Someone may actually take your advice and get hurt.