Have your equipment checked...Trust no one

[keller34]

I thought that this may help a few new divers as it did both my sons.

We recently bought used gear, 2 full sets, from a local person. I know what to look for and how to check to see if things are not right. One of the regs free-flowed when pressing the purge. I thought great, I can teach my boys something. Turn lemons to lemonade.

So I took them to a friend's pool, knowing that the equipment was faulty, to show them why equipment needs to be checked. They thought that everything looked good and it did from the surface.

I put on a set and went in the shallow area. I told them that I am going to go under for a few minutes and then I will be back up. I went down with the first set, knowing that it was ok and to show them it was ok. Everything went fine, then I came up and switched gear to the faulty one and had them get in the pool with their masks. As I went down I showed them the bc hose and how it had a leak even though it looked ok. Then I pressed the purge on the reg, the look on their face was priceless.

When I came up they asked what happened, thinking that it blew up because of all the air, and I told them what the failure was. I explained to them that even though it looks good and the person you are buying it from says he had them serviced a few months ago, always take them for service. Then when we got home I showed them some videos of what equipment failures can do to you if you are not careful and plan for the unexpected.

They are going to take the OW cert next month along with 3 of their friends, I will be taking it again with them to show my support and who knows the instructor may teach me something mine did not. Always willing to learn. I just got back into diving not long ago, 20 years is a long time not doing it.

So always get the gear you buy serviced if it is used, never trust a person at their word. It is not their life that is on the line, it is yours.

 

[tplyons]

Great moral! I always get used gear serviced, unless I buy it from a member of the usual dive group. I'm confident in their gear (we all borrow each other's to try out new rigs too) and would not hesitate to buy from them.

 

[SeaCobra]

Actually, might not be anything wrong with the reg. Modern regs are designed to flow, perhaps the venturi was going into effect. What make and model reg was it?

 

[keller34]

Actually, might not be anything wrong with the reg. Modern regs are designed to flow, perhaps the venturi was going into effect. What make and model reg was it?

Older R380, They will be getting new regs soon for a present in about 2 months.

 

[Griffo]

On the flipside I picked up a set of regs from my LDS after a service, and the moment I turned the tank on the o-rings blew out of the LP hoses as they hadn't even put the hoses on correctly. Never trust gear that you get serviced either.

 

[buddhasummer]

On the flipside I picked up a set of regs from my LDS after a service, and the moment I turned the tank on the o-rings blew out of the LP hoses as they hadn't even put the hoses on correctly. Never trust gear that you get serviced either.

Stories like these and my own personal experience with shop "servicing" are exactly what drove me to self servicing.

 

[herman]

Funny thing is, if I read you right, the "faulty" reg may well be the only one correctly tuned. Almost any modern reg if properly tuned will violently freeflow when the purge is pressed with no back pressure. This is esp true of those with a +/- venturi control lever that is set to + but most will freeflow in the full - direction if purged hard enough. Venturis designed into them will create and sustain a full freeflow until it is stopped, it's a nuisance but to get the performance and ease of breathing up, it's a necessary tradeoff. Any reg mid to high performance reg should freeflow when subjected to a full purge button press, if not odds are the tech who set it up did not do his job correctly If mine do not freeflow under full purge , I go looking for the problem..

 

[miketsp]

Ditto to Herman. All primary second stages used by my family will free flow when purged while levers are in the "dive" setting. Only my reserves don't free-flow because they're deliberately detuned.

 

[Crowley]

I have to agree with other posters that a second stage will often free-flow when the purge button is depressed at the surface or in very shallow water. Regulators are very finely balanced and often hover at the edge of freeflow/noflow so - whilst the equipment as described by the OP may well have been faulty, in general, a reg that freeflows when not under pressure is, actually, perfectly sound.

I have to say that in my experience, this is more true of the "basic" regulators - for example my own personal ScubaPro Mk25 never, ever did this, although the MkII (the basic SP reg) which is one of the most popular regulators for equipment rental at dive centres does this an awful lot. It's not a design flaw, the MkII is one of the most bullet-proof regulators in existence (and also relatively inexpensive, hence its popularity amongst dive centres that rent equipment).

The venturi effect - which is that a decrease in surrounding pressure will cause a gas/fluid to flow more rapidly to compensate, is the basic principle of scuba regulator design. We inhale, which decreases the pressure in the second stage, which activates a lever, and the resulting opening of a valve plus the decrease in pressure means that gas (compressed air, in this case) goes into your mouth. Pressing the purge button has a similar effect - the rapid flow of gas creates an overall decrease in pressure inside the second stage and this keeps the valve open - hence the freeflow.

Some regulators have a "dive/pre-dive" setting to help combat the freeflow caused by this effect - it basically sticks a bit of moulded plastic in the opening of the mouthpiece (inside the second stage) which constricts the flow of gas and negates the venturi effect. Many basic regulators don't have this, so if you hit the purge button and it freeflows, just stick a finger in the mouthpiece opening and the resulting slight pressure build-up in the second stage will shut off the gas flow and stop the freeflow.

I'm not saying the OP is wrong, and I implore all divers who own their own regulators to look after them and have them serviced at appropriate intervals, but there may be resultant stress (and expenditure) in having incorrect information - if you think a freeflow is a technical fault then you may end up paying a lot of money to dive shops to have your reg un-necessarily serviced, and then potentially think the DC is at fault. If a regulator is free-flowing at any depth greater than a few metres, however, this is definitely a problem, and you should have your first stage checked - because technical problems resulting in freeflow underwater are more often associated with defects in the first stage rather than the second.

Safe Diving,

Crowley.

 

[keller34]

I would agree that it would be design for it to do that. It also will do it when inhaling I have tested. However, on further examining the reg it is bad. So now I am just waiting for all the regs to be serviced. It will take a week for me to get them all back. Thats ok though as I am in no big hurry. I have my own gear and they are not certified yet.

Thank you all for input on this.