“DO AS I SAY, NOT AS I DO!”
In keeping with my philosophy, that all divers (including manufacturers and instructor trainers) should be willing to admit when they screwed up, I share the following event which happened to me today while teaching a CCR Cave course at Peacock Springs. My hope is that my lack of maintenance on my personal CCR unit can somehow be a motivation to others to not follow suit!
As is my usual practice, I had prepped my unit the night before, including scrubber fill, cylinder top offs, battery charging, leak tests, flapper valve tests, checked my calibration, etc. etc. Everything looked 100% good to go. Upon arriving at the dive site this morning, I placed my CCR on the tailgate of my truck and proceeded to go through go through my secondary checklist prior to dressing for the dive. (Checking my O2 cells, checking O2 and dil pressures, pulling a negative and a positive, etc.) As part of my secondary checklist, I turned on my O2 gas. I could hear what sounded like a small leak escaping from somewhere in the vicinity of the O2 first stage. I put my fingers down there to see if I could feel precisely where the leak was coming from. I could feel it, but couldn’t identify the exact location. At that point, I decided that I needed to remove the reg from the tank valve so I could inspect it more closely. In order to do so, I needed to depressurize the lines, so I pushed the O2 manual add valve to relieve the pressure. That’s when it happened! Kaboom!
The noise was incredible and at first I wasn’t sure if all of my body parts were still intact. After I got my wits about me, I sprinted away from my unit in fear that perhaps the tank was going to blow or even worse, perhaps my truck might go up in flames! After a quick inventory of my body parts, I seemed to be no worse for the wear, other than a burned finger that is now black in imbedded Delrin in my skin!
Upon closer examination of my unit, I discovered that the O2 MAV had exploded, button missing, and melted inside and partially outside. The hoses on that side of my unit were melted including braided hoses, which surprised me greatly. Pieces of metal hose fittings were exploded and missing. My entire unit was covered in soot. It basically look like someone tossed it in a campfire momentarily! O2 spg was burned up, the T-piece was destroyed, etc. etc.
After several mins. of dealing with the shock of an explosion in my proximity, I started to investigate what had happened. One of the first things I noticed is that my O2 first stage did not have an opv attached. I’m guessing that sometime during the past year, I had removed it and plugged it at a dive site, because it had started leaking. I honestly don’t remember when this would have happened, but a quick inventory of 5 other CCR instructors that were in the near vicinity when it happened, proved that all 5 of the other guys also did not have an opv currently attached to their O2 first stage, for exactly the same reason. Go figure!
Also, when checking my positive pressure on my unit, I had filled my counterlungs with O2. In hindsight, this was really dumb, as it undoubtedly contributed to the volume of O2 in my loop which most certainly was above ambient pressure due the suspected IP creep on my first stage.
Speaking of IP creep, the brand of first stage on my unit has had a history of faulty seats over the past year, and we have seen numerous regs fail with IP creep. Of course, this should not be catastrophic provided that there is an OPV on the line somewhere.
And lastly, and perhaps most importantly and quite honestly more embarrassingly, I had not serviced my MAV in 2 or 3 years. The SubGravity owners manual states specifically that the MAVs should be cleaned and serviced at a minimum of once per year or more often as needed. Apparently, I don’t listen very well!
Fortunately, the only serious injury was to my unit and to my pride! It’s always fun to have an explosion in the near vicinity of half of the cave diving world and have them come running to see if you are still alive! I have a finger which is burned and is stained from black Delrin in my skin, but other than the ringing in my ears, I’m good to go! Fortunately, as per my predive protocols, I was not wearing my unit at the time I turned it on! I am grateful that it was not more serious as it easily could have been!
So in keeping with my personal philosophy, of sharing my screw ups so that other might learn from them, please be diligent about the following points:
1. SERVICE AND MAINTAIN YOUR EQUIPMENT ON A REGULAR BASIS ACCORDING TO THE MANUFACTURERS RECOMMENDATIONS!
2. REPLACE ALL BROKEN OR MISSING PARTS IMMEDIATELY, WITHOUT FAIL!
3. DON’T OVER INFLATE YOUR COUNTERLUNGS WITH O2!
4. TURN ON YOUR GAS BEFORE DONNING YOUR CCR!
5. TREAT O2 WITH EXTREME CAUTION! IT CAN AND WILL CREATE QUITE A MESS!
Please feel free to chastise me, although I guarantee that you can not possibly do so more stringently than I have already done to myself!
In keeping with my philosophy, that all divers (including manufacturers and instructor trainers) should be willing to admit when they screwed up, I share the following event which happened to me today while teaching a CCR Cave course at Peacock Springs. My hope is that my lack of maintenance on my personal CCR unit can somehow be a motivation to others to not follow suit!
As is my usual practice, I had prepped my unit the night before, including scrubber fill, cylinder top offs, battery charging, leak tests, flapper valve tests, checked my calibration, etc. etc. Everything looked 100% good to go. Upon arriving at the dive site this morning, I placed my CCR on the tailgate of my truck and proceeded to go through go through my secondary checklist prior to dressing for the dive. (Checking my O2 cells, checking O2 and dil pressures, pulling a negative and a positive, etc.) As part of my secondary checklist, I turned on my O2 gas. I could hear what sounded like a small leak escaping from somewhere in the vicinity of the O2 first stage. I put my fingers down there to see if I could feel precisely where the leak was coming from. I could feel it, but couldn’t identify the exact location. At that point, I decided that I needed to remove the reg from the tank valve so I could inspect it more closely. In order to do so, I needed to depressurize the lines, so I pushed the O2 manual add valve to relieve the pressure. That’s when it happened! Kaboom!
The noise was incredible and at first I wasn’t sure if all of my body parts were still intact. After I got my wits about me, I sprinted away from my unit in fear that perhaps the tank was going to blow or even worse, perhaps my truck might go up in flames! After a quick inventory of my body parts, I seemed to be no worse for the wear, other than a burned finger that is now black in imbedded Delrin in my skin!
Upon closer examination of my unit, I discovered that the O2 MAV had exploded, button missing, and melted inside and partially outside. The hoses on that side of my unit were melted including braided hoses, which surprised me greatly. Pieces of metal hose fittings were exploded and missing. My entire unit was covered in soot. It basically look like someone tossed it in a campfire momentarily! O2 spg was burned up, the T-piece was destroyed, etc. etc.
After several mins. of dealing with the shock of an explosion in my proximity, I started to investigate what had happened. One of the first things I noticed is that my O2 first stage did not have an opv attached. I’m guessing that sometime during the past year, I had removed it and plugged it at a dive site, because it had started leaking. I honestly don’t remember when this would have happened, but a quick inventory of 5 other CCR instructors that were in the near vicinity when it happened, proved that all 5 of the other guys also did not have an opv currently attached to their O2 first stage, for exactly the same reason. Go figure!
Also, when checking my positive pressure on my unit, I had filled my counterlungs with O2. In hindsight, this was really dumb, as it undoubtedly contributed to the volume of O2 in my loop which most certainly was above ambient pressure due the suspected IP creep on my first stage.
Speaking of IP creep, the brand of first stage on my unit has had a history of faulty seats over the past year, and we have seen numerous regs fail with IP creep. Of course, this should not be catastrophic provided that there is an OPV on the line somewhere.
And lastly, and perhaps most importantly and quite honestly more embarrassingly, I had not serviced my MAV in 2 or 3 years. The SubGravity owners manual states specifically that the MAVs should be cleaned and serviced at a minimum of once per year or more often as needed. Apparently, I don’t listen very well!
Fortunately, the only serious injury was to my unit and to my pride! It’s always fun to have an explosion in the near vicinity of half of the cave diving world and have them come running to see if you are still alive! I have a finger which is burned and is stained from black Delrin in my skin, but other than the ringing in my ears, I’m good to go! Fortunately, as per my predive protocols, I was not wearing my unit at the time I turned it on! I am grateful that it was not more serious as it easily could have been!
So in keeping with my personal philosophy, of sharing my screw ups so that other might learn from them, please be diligent about the following points:
1. SERVICE AND MAINTAIN YOUR EQUIPMENT ON A REGULAR BASIS ACCORDING TO THE MANUFACTURERS RECOMMENDATIONS!
2. REPLACE ALL BROKEN OR MISSING PARTS IMMEDIATELY, WITHOUT FAIL!
3. DON’T OVER INFLATE YOUR COUNTERLUNGS WITH O2!
4. TURN ON YOUR GAS BEFORE DONNING YOUR CCR!
5. TREAT O2 WITH EXTREME CAUTION! IT CAN AND WILL CREATE QUITE A MESS!
Please feel free to chastise me, although I guarantee that you can not possibly do so more stringently than I have already done to myself!
