Gas blocks on Mantas

Pawel Szopinski

Just a quick question to those who already own Manta lungs or use similar gas blocks. What type of off-board connector have you decided to go with?

I would ideally stick to standard LP connector, so I can hook up my bailout to my wing, suit or inflate bags if I have to without having too many hoses, but I'm obviously concerned with the water ingress.

As far as I can see both blocks only feed the lungs, no solenoid or high pressure running through. However, the issue of corrosion still exist. How much of an issue is it for you? Does it have a one way valve or can the water enter the 1st stage when the pressure drops enough in for it to drain through the hose?

engmannen

I have short hoses on QC6 and they feed the first stages and lungs so everything works as normal! The amount of water entering the system is some milli liters and will go up in the lung, no probs!

/Engman

Pawel Szopinski

1st stages?

engmannen

Apeks DST with 9,5 bar intermediate pressure both on in- and offboard

Pawel Szopinski

Interesting. Thanks.

dykkermads

QC6 directly into the block itself with no hose. Water limits to a drop or two inside the swagelok itself which can be cleaned. All other water poors directly into the lung.

1. stages are DS4 standarts, both in- and offboard.

/Mads

seeboth

I think the problem with the standard 'wing' lp connector is that there is no valve on the male side, so you would have to always have a hose connected to it other wise the feed gas from your on board would free flow out of your quick connect.

There are two solutions to this issue though:

1) a'la pelagian is to use the standard quick connect to connect your on-board to the manual add block. To connect your off-board you hold the block upside down, disconnect your on board, and connect your off board to the standard quick connect. The problems with this set up are:

A) there are more steps to connecting your off board gas,
B) You cannot have your on board and off board gas connected at the same time, and
C) your off board is completely isolated from your on board, so your off board will not feed your orifice, just the manual add (this could be a positive depending on logistics, such as you want your on board to run your solenoid and off board to run your manual add, or if you are diving a COPIS meg and don't want your depth compensating off board 1st stage to feed the orifice, or you blew a hose, or other Boom scenario, on your on board reg)

2) a'la UTD, you can use a QC6 to connect your off board, but make a pig tale consisting of a male standard quick connect, connected to a female QC6. Keep the pig tale attached to the standard quick connect lp hose on your off board tanks (you could keep it connected to your gas block but the male standard quick connect would allow water into the adapter and possibly allow corrosion), then plug in your off board when ever your need. This system allows you to connect any standard LP hose to your off board connections, even from somebody else's off board if you need. Cons are:

A) if you need to connect your off board to your wing or drysuit, you have to try and not lose your adapter, (figure out some way of tethering it to your bailout?)
B) you need to install a slider shutoff valve on your on board feed line in order to isolate your off board gas from your on board. This is important if you were forced to plug in your off board due to an on board boom scenario, or if you want to use your off board to exceed the depth limitation of your copis meg.

I should say I dont have a manta lung yet, so I am not sure if the gas blocks come with slider shut off valves, but I would consider them necessary.

I would choose method 1, but I dive a COPIS in fresh water, so there is less worry about salt build up and corrosion in the add valve, and I dont want my off board feeding the orifice connection.

Between these two methods #1 might take longer to connect gas to the breathing loop, where #2 would take longer to connect to your wing/ drysuit. In my experience the loop PO2 is normally stable enough that you have a couple of seconds to connect your off board gas before 'it hits the fan, but if you need to add buoyancy gas to your wing or suit, a couple of seconds could mean an uncontrolled decent (if you've ever ran out of argon on decent you know how uncomfortable this can be).

Hope that all makes sense,
Al