Manifolds on Twins: It's an open and shut case

[dalegray]

Totaly closed, you balance the cylinders by swopping regs every 10 bar.

This has 2 advantages:

1. if you have a freeflow half your gas is safe, no matter how long it takes you to reach your valves.

2. by swopping regs you are ensuring both are working.

Downsides:

None

[wreckweasel]

Originally Posted by dalegray

Totaly closed, you balance the cylinders by swopping regs every 10 bar.

This has 2 advantages:

1. if you have a freeflow half your gas is safe, no matter how long it takes you to reach your valves.

2. by swopping regs you are ensuring both are working.

Downsides:

None

More Downsides;

- Extra un-needed o rings, valve. why not just use independents
- if team/buddy diving, how do you air share, 2 long hoses?

[dalegray]

Originally Posted by wreckweasel

Extra un-needed o rings, valve. why not just use independents

So in the event of shutting one side down, then all gas is still reachable.

Originally Posted by wreckweasel

- if team/buddy diving, how do you air share, 2 long hoses?

Just give them the hose from the cylinder with the long hose on. you breath from 1 cylinder, they breath from the other. no problem

[wreckweasel]

Fairy snuff, point made

[dalegray]

Originally Posted by wreckweasel

Fairy snuff, point made

I must have done something wrong, agreement doesn't usually come this quick

[nigelH]

Originally Posted by dalegray

I must have done something wrong, agreement doesn't usually come this quick

You haven't been here long enough to understand the fine balance between what we find funny and what we find stupid.
This spills over into when we dig our heels in and bitch and when we just let it be.

nigelH

[gunsentry]

Downsides:

None[/quote]


Errr NO... Task Loading.

[Janos]

Originally Posted by dalegray

Downsides
None

I dive independents when abroad, and I find reg swapping a bit of an arse. I can do it, but I prefer not to. Also, I prefer to have the long-hosed reg in the same place throughout the dive, as I'd prefer it if my buddy didn't have to work out which one was which in an OOA situation.

Laters,
Janos

[Mark]

Originally Posted by dalegray

Totaly closed, you balance the cylinders by swopping regs every 10 bar.

This has 2 advantages:

1. if you have a freeflow half your gas is safe, no matter how long it takes you to reach your valves.

2. by swopping regs you are ensuring both are working.

Downsides:

None

Hi,

I don't understand why you have a manifold at all.

A manifold when used 'correctly' is a potential failure point but the advantages outweigh the risks. You have the same risks but are getting none of the advantages. You are then introducing more risk with all the reg swapping (swapping every 10Bar is a lot of task loading/risk if you are going to be using 150Bar of gas! What a PITA that must be), 2 spgs etc. etc...

You would be safer with completely independant tanks or rethink how you dive your manifolded twinset.

Best regards & merry xmas,

Mark.

[dalegray]

Originally Posted by Mark

Hi,

I don't understand why you have a manifold at all.

A manifold when used 'correctly' is a potential failure point but the advantages outweigh the risks. You have the same risks but are getting none of the advantages. You are then introducing more risk with all the reg swapping (swapping every 10Bar is a lot of task loading/risk if you are going to be using 150Bar of gas! What a PITA that must be), 2 spgs etc. etc...

You would be safer with completely independant tanks or rethink how you dive your manifolded twinset.

Best regards & merry xmas,

Mark.

Point taken and I do agree, if I am diving caves I use a side mount system, so I am diving independants, I also have 15 litres that I use as total independants if I am diving solo.

However, if I am diving with a buddy, I feel the ability to reach turned off gas is critical, because if I am diving thirds and have to turn off a cylinder, I only have enough gas for me, so if I dive with a buddy I use a manifold system (and before anyone says that buddies should be left if it endangers yourself, one of my main buddies is my 12 year old daughter)

I don't find reg swapping a pain, and it ensures both regs are working. If I wasn't swapping for the reasons I do I would be swapping to ensure my bail out was working.

2 spg's, I think this should be standard kit for all, if you have to do a shut down, you will already be stressed, why add to that stress the worry that you haven't saved enough air with your shut down. If you know you haven't saved enough you can make plans accordingly.