Quick disconnect for second stage?

[HowardE]

While you can get a 9/16 -> Scuba QD (I use one on my helmet for EGS) and while the amount of gas supplied in the LP hose would serve you as you expect. Your configuration would only confuse your students by how odd it would look to them. Keep a wrench in your box, and swap the hose at the first stage. It's a 30 second switch out.


BTW - Here's an example of a QD for 2nd stage (similar to what I have installed on my helmet - which is the same as the inlet on a scuba 2nd stage) ->

 

[hypertech]

Did they not explain the difference between Low Pressure (LP), Intermediate Pressure (IP) and High Pressure (HP) when covering regulators on the equipment section of your DM course?

What is this supposed to mean? My first stage has 4 LP (low pressure) ports. The IP (intermediate pressure) on all of them is the same. There are not 3 different pressure rated ports. There are two LP and HP, and the IP is the pressure above ambient of the LP ports.

 

[HowardE]

I'm curious... with all of the "Don't use a quick disconnect, they will fail" sayers out there. Has anyone seen a QD fail? Has anyone tried to disconnect a QD whilst pressurized? (it's not easy)

 

[DevonDiver]

What is this supposed to mean? My first stage has 4 LP (low pressure) ports. The IP (intermediate pressure) on all of them is the same. There are not 3 different pressure rated ports. There are two LP and HP, and the IP is the pressure above ambient of the LP ports.

It meant nothing more that what it asked. In your OP you mentioned you were a newly qualified DM. A basic understanding of what ports can feed what hoses/equipment should reasonably have been covered in the DM course. I wondered if that had been covered? If not, I would have phrased my reply to ensure you understood why, rather than just stating what.

Hope that makes sense.

 

[PfcAJ]

I'm curious... with all of the "Don't use a quick disconnect, they will fail" sayers out there. Has anyone seen a QD fail? Has anyone tried to disconnect a QD whilst pressurized? (it's not easy)

Yes, I have (small leaks, usually), and yes, I've disconnected both swagelocks and regular BC disconnects while pressurized. The whole point is that they are quick to disconnect

 

[hypertech]

It meant nothing more that what it asked. In your OP you mentioned you were a newly qualified DM. A basic understanding of what ports can feed what hoses/equipment should reasonably have been covered in the DM course. I wondered if that had been covered? If not, I would have phrased my reply to ensure you understood why, rather than just stating what.

Hope that makes sense.

Actually, no, it doesn't at all. Like I said above - IP is not a port (at least not on any of my gear it isn't) IP is a measure of the pressure of a LP port. Any of my LP ports can be used for a regulator, inflator hose, or whatever else interchangeably. Further, LP and HP ports have different diameter fittings and no where did I even hint at attempting to run an inflator or a reg on a HP port which would just be silly.

 

[DevonDiver]

Ok..I'll put it simply. I was confused when you said:

.... it won't be used at depth, so I thought the airflow would be OK? Or am I kidding myself?

I read that as a question about the supplied pressure. With that assumption, I wanted to clarify what you understood about LP/IP/HP. That is clear now

I guess you were asking whether airflow through QD would be hindered by the design/capacity of the QD itself?

 

[hypertech]

IP at depth should be roughly the same so LP/IP/HP really has nothing to do with operation at depth, but at 2, 3, 4 atm, a lot more air would need to move through the fitting to the reg. Therefore, the comment, "airflow would be OK" was related to any possible restriction in flow capacity due to a smaller orifice in the QD.

 

[HowardE]

Yes, I have (small leaks, usually), and yes, I've disconnected both swagelocks and regular BC disconnects while pressurized. The whole point is that they are quick to disconnect

Ok wiseguy... I know they are quick... but not like touch it and it will come apart... especially under pressure. I want to know if anyone has experienced a total failure, since they areso often poo pooed as failure points. I mean I've seen regular hoses leak a little because of bad o rings...

 

[knowone]

There is high, intermediate and low pressure regarding regs despite your limited knowledge regarding "your" gear and as idiotic as is leaking gear, your picking apart of posts to suit and supplement your subsequent ones is as closed as subjecting students to your inappropriate configurations and laziness.