H.U.B. dump valve malfunction

[Wall]

I am a PADI Instructor.

My wife has a MARES (originally DACOR) H.U.B.

Recently it was serviced by a 5 Star PADI Dive Center and an authorized Mares service center who replaced 6 different parts including a dump valve parts kit.
Two weeks later, on a trip to FIJI, at 50 feet she tried to deflate it and it kept inflating - I had to fight like hell to keep her down and stop a potential problem.

It never did that before and has been on hundreds of dives.

We had to use the emergency deflate valves to control it after that.

We took it back to the service center after the trip and the service person says that he could find nothing wrong, and that he called MARES and they say that the valve needs to pump in a little air to open the deflate valve – that’s what it is supposed to do. I understand that, but after the dump valve opens, it continues to inflate the BC instead of deflating it.

It is a life threatening situation to be in – what would happen on a deep dive and a sudden uncontrolled ascent occurs just regulating buoyancy and your buddy is not up close and does not work out that you have a BC malfunction and can pull the rip cord for the emergency air dump?

I think that the dump valve is malfunctioning and I think that the valve design on the HUB is faulty and it needs to be recalled. Whom can I go to with this information? Does MARES have a QA referral person? The Dive Center people do not seem to understand the gravity of the situation, nor does the tech seem to believe what happened and says that it is functioning as it should, although one of their own instructors was on the dive, witnessed the event, and demonstrated the malfunction after the dive, and told her to bring it back. There is no UL label on the HUB (never was).
Thanks.

 

[Jim Lapenta]

this should be good. Based on some of their responses to posts here I have a new respect for Mares. I don;t think they will be happy with a dealer telling a customer an obvious defect is something they cannot take care of.

 

[Zak OHara]

I am a PADI Instructor.

My wife has a MARES (originally DACOR) H.U.B.

Recently it was serviced by a 5 Star PADI Dive Center and an authorized Mares service center who replaced 6 different parts including a dump valve parts kit.
Two weeks later, on a trip to FIJI, at 50 feet she tried to deflate it and it kept inflating - I had to fight like hell to keep her down and stop a potential problem.

It never did that before and has been on hundreds of dives.

We had to use the emergency deflate valves to control it after that.

We took it back to the service center after the trip and the service person says that he could find nothing wrong, and that he called MARES and they say that the valve needs to pump in a little air to open the deflate valve – that’s what it is supposed to do. I understand that, but after the dump valve opens, it continues to inflate the BC instead of deflating it.

It is a life threatening situation to be in – what would happen on a deep dive and a sudden uncontrolled ascent occurs just regulating buoyancy and your buddy is not up close and does not work out that you have a BC malfunction and can pull the rip cord for the emergency air dump?

I think that the dump valve is malfunctioning and I think that the valve design on the HUB is faulty and it needs to be recalled. Whom can I go to with this information? Does MARES have a QA referral person? The Dive Center people do not seem to understand the gravity of the situation, nor does the tech seem to believe what happened and says that it is functioning as it should, although one of their own instructors was on the dive, witnessed the event, and demonstrated the malfunction after the dive, and told her to bring it back. There is no UL label on the HUB (never was).
Thanks.

Hi Wall,

Thanks for making this post, I can certainly understand your concerns. I'd like to address your comments.

First, there are no problems with the Air Trim system. This system has been in production for many years and has proven to be very reliable. I think by the fact you have 100's of dives on it with no problems should testify to this. I also think that it is probably not coincidence you experienced some problems just after you had service completed. It sounds like you took the bcd to is a qualified technical center, however it perfectly reasonable that something could have happened by mistake at the point of service. Ex: I took my vehicle in for a light bulb replacement the other day, when I left the dealer, I turned on my front windshield wipers, and the back wiper activated, and the same applied to the rear switch activating the front. The tech, accidentally rehooked the wires backwards. Not to make light of your situation, I'm just trying to explain even the most qualified people can accidentally make a mistake reassembling. I'm also not accusing the service center of this, as it is impossible for me or anyone to analyze over the internet. My suggestion would be to take it back to the service center, have them look at it again. If the bcd is pressurized, the deflator is activated, and the bcd does not fill up with air, then it really shouldn't do this in the water. If it does, then they can try to figure it out. Alternatively the store can send it to our service tech for review.

Again, I'm not trying to make light of your situation. I completely understand your issue, and it is not the way the bcd should function. The deflator valves are designed to use very little air to force the valve open, then ambient pressure takes over squeezing air out of the bcd to the highest point. This could be the shoulder valve or bottom valve depending on which is higher in the water column. Air should not be leaking past the valve into the bladder of the bcd. All I can think is the valves were not reassembled properly, or something has come loose, post service. I am not in a position to point fingers from my desk. The bcd must be analyzed by a tech to fully understand what is going on.

This is also a good example of why we should all be very cognitive of what situations can occur underwater and how to deal with them. Sounds like you did a great job, managing the incident. This very same thing can happen to a tradition inflator valve / hose assembly. In most inflators, it is a simple shraeder valve allowing air in and out of the bladder. These often become corroded, plugged with salt, etc., and can easily become stuck in the open / inflate position resulting in a similar issue as you stated.

If you need further assistance please let me know and I'll try to assist. Note: I'm out of the office all next week and won't be able to respond until 2/14/10.

Sincerely,