Visual Inspection not being completed

[KeithG]

I have never seen a water tank fill in the Caribbean. The "more efficient" dive ops fill tanks in place on the boat.

The standard fill process is to leave the cap off after you remove your reg to signify the tank needs to be filled. This leaves the yoke exposed to salt water splashing, rain or water dripping off divers. The tank fill monkeys then slam the fill whips onto tanks as fast as possible. Once full, the cap goes back on.

A Caribbean dive op we use fills around 300 tanks a day.

P.S. I have no idea if they do a quick crack of the valve before they attach the whip. This would make great sense as it would detect empty tanks...

 

[Freewillow]

Personally I don't think an annual VIP is really necessary unless the tank has been emptied completely or dropped or gouged etc. If it has a big dent or gouge on the outside it's unlikely it would pass the preliminary hydro testing. As long as a tank has some air in it I can't imagine how water could get in unless someone opened the valve all the way to empty it and some condensation collected inside.

It might be good to know the name of the dive op just the same so I can avoid them anyway. They don't sound real swift.

Water gets in the tank pretty easely if the purge process is not done regularly during the inflation process.

 

[Basking Ridge Diver]

Water gets in the tank pretty easely if the purge process is not done regularly during the inflation process.

How is this possible if the tank is pressurized? The pressure in the tank would be greater than the water pressure to work its way into the tank - unless as stated above the tank were emptied or close to empty...
Right?

 

[KeithG]

How is this possible if the tank is pressurized? The pressure in the tank would be greater than the water pressure to work its way into the tank - unless as stated above the tank were emptied or close to empty...
Right?

filling it causes the problem.

if there is water on the valve face, then when the whip is clamped on, there is water "inside" the whip face. Once you open the valve the water is driven into the tank.

 

[Basking Ridge Diver]

I can completely understand that logic - what I can not understand is Willows point of purging unless it is the way I am reading it...

I am reading it as purging a single tank multiple times... not sure I understand...

 

[KeithG]

I can completely understand that logic - what I can not understand is Willows point of purging unless it is the way I am reading it...

I am reading it as purging a single tank multiple times... not sure I understand...

at fill time, before you attach the whip you need to crack the valve a bit to blow away any moisture sitting on the valve face. you then attach the fill whip.

 

[RayfromTX]

Compressing air forces the water out of it. The compressor will have one or more coalescers that are designed to catch this condensation before it gets to the filters and driers. These must be regularly drained during the compressor operation to avoid flooding the dessicant and eventually the tanks that are being filled.

 

[RayfromTX]

In an AL80 pumped from humid outdoor air the water that is squeezed out during compression to 3,000 psi is around a cup. This water is managed by coalescers and dessicant driers. Water management is also critical for removal of CO as the hopcalite that converts the CO to CO2 is rendered ineffective by high moisture levels.

 

[Cr.padlo]

I would see if the shop keeps the viz records inside...I did an op in Cozumel and they had us review the viz stickers (labelled with the serial code in the shop before the dive. They stated that they didn't put the label on the tank because they were used so often and they tended to do a viz every 6-9 months and the high volume of dives led to the labels being damaged and falling off too often. I would ask about that as they may not place the viz labels on the tanks for practicality purposes.

 

[Freewillow]

Rayfrom is telling you what I meant. Humid air in the carribean, when compressed produced a significant amount of water. If the operator purges the system and replaces the dessicant/CO filter often, this will be OK. My experience is that these 2 operations may not be done as regularly as needed. Hope you understand now