Failure rate of first stages? what is real need for a spare first stage on a trip

[NYCDiverBlue]

Hello,

in this thread:
First time reg buyer: some questions

@tbone1004 wrote:

I would highly recommend ordering a doubles regulator set so you have a spare first stage if you are travelling. First stages are unpredictable little buggers, and having a spare first stage is a great insurance policy to ensure you don't have to rent a regulator and miss a dive or two while you are travelling.
Deep 6 Signature Double Tank Regulator Package - Regulator Packages - Regulators
I'd also recommend going to Dive Gear Express and ordering an IP gauge which is a required tool IMO for all divers, especially those that own their own regulators

@tbone1004 thanks for you advice. I am curious, you wrote" First stages are unpredictable little buggers". This is a relative statement. Just how unreliable are first stages in your opinion? What do you think the failure rate is? Do Deep6 first stages fail in a way that is not fail safe(some would say that ACD first stages could fail in a way that is not fail safe as they close).

Please know that I am not being provocative as I am trying to decide which Deep6 set up to buy yet I am thinking ....really? .... in 100 dive trips(with proper maintenance) of a week long with 20 dives per trip, what would the failure rate be? in my VERY inexperienced mind, I would think it would be less than 1% over that total sample size. Maybe others could weigh in what would be the expected failure rate of first stages? Buying a spare first stage is like buying an insurance policy, yet since one could always rent(unless in remote area) a regulator if need be, one would want to weigh all the costs of buying(and carrying around) a spare first stage.

Thanks for any input.

 

[Divectionist]

A modern and well looked after, properly serviced first stage is extremely unlikely to just fail on you. Most if not all would be downstream designs, failing open rather than shutting, including the second stage. I avoid ACD but cannot comment on their recent designs.

I do not think that it makes sense to carry a backup reg on dive trips, particularly if you could rent one in the very unlikely event.

In practice, I always dive with 2 regs because I believe in redundant air supply on every dive, be it pony, twins, side mount. If you go that way, you may as well invest in a redundant tank of some sort. You'll still have to find a back up if one fails, or dive with only one for the remainder of the trip. This would of course be the most paranoid bit, if one just failed on you

 

[runsongas]

i have had to switch to a backup first stage once due to a hp seat failure on a trip. this was after nearly 40 dives in on an extended multi week trip. i usually plan to bring an extra spare reg for trips lasting over a week. but mostly because i don't like using unbalanced regs if i can help it and rental fleets rarely have balanced regs. i could have finished that trip on rental equipment otherwise.

 

[NYCDiverBlue]

@Divectionist What would you recommend for one who is a travel diver with regards to having a redundant tank/air supply of some sort? While the vast, vast majority would not travel with their main tank(s), are there any small tanks, secondary air supply that are easy to travel with? I think I have seen small tanks that can be filled off of a regular tank. Thus, especially at a resort where one could get unlimited diving, one could theoretically travel with a light enough secondary tanks(my understanding is the valve has to be completely off for air travel with tanks). Do any such tanks exist? If so, what size and set up would you recommend?

thanks in advance

 

[Bob DBF]

@Divectionist covered it well. Traveling I carry a spare first and second, and diving locally, an extra reg set, I have never actually needed to use them myself, but a few friends have been happy I brought then along.

If you take care of your gear, it will take care of you.


Bob

 

[Divectionist]

@Divectionist What would you recommend for one who is a travel diver with regards to having a redundant tank/air supply of some sort? While the vast, vast majority would not travel with their main tank(s), are there any small tanks, secondary air supply that are easy to travel with? I think I have seen small tanks that can be filled off of a regular tank. Thus, especially at a resort where one could get unlimited diving, one could theoretically travel with a light enough secondary tanks(my understanding is the valve has to be completely off for air travel with tanks). Do any such tanks exist? If so, what size and set up would you recommend?

I would first try to see if you can rent a pony bottle at your destination, and then bring my own rigging kit to sling the bottle without doing anything permanent to it (bit of line, hose clamp, couple bolt snaps, you can fashion it in about 5 minutes). Otherwise yes, the valve needs to come off and it is a big weight and hassle.

The tank size entirely depends on your gas consumption and general max depths you dive to. I suggest looking at your SAC/RMV, double or triple it for stress, depending on how cool of a cat you are, and with these figures allow for at least 2min at your max depth (to control the situation) and then a slow ascent incl. safety stop to surface. This will give you the min. volume for your pony.

You can get pony bottles of all sized, most opt for aluminium because they are not as negative, particularly for larger capacities, but I actually use a 2l faber steel with 232 bar, which gives me 464litres of air (16cuft) because it is light on land, compact, and at that size not too negative with less of a weight swing when in use. These are mostly used as rebreather bottles but I love mine. Here she is. I since swapped out the bolt snaps for a couple with much larger loops to put my finger through when attaching/detaching.

 

[Khrissi]

O ring failures have been my worst ( yoke adaptor ) so bring my own ( new) adaptor fr DIN cylinders. Not heard of first stage failure. K

 

[buddhasummer]

I've never had a "failure" in over 20 years, 2 annoyingly squealy piston first stages, but that's about it. I don't dive piston regs anymore, we never got on.

It's for this reason, i.e travel, that I go with an unsealed Apeks FSR and either Conshelf 14 or G250/V seconds, all can be serviced by me on the back of a boat in a very short amount of time, very simple with minimal tools required. Thus far I've never needed to do it. The tools I need plus service kits are way lighter than a reg set.

But, I understand not everyone is into DIY.

Given my experience with failure rates, 0%, even if I wasn't into DIY, I'd take the risk assuming rental was an option in worst case scenario.

 

[Divectionist]

O ring failures have been my worst ( yoke adaptor ) so bring my own ( new) adaptor fr DIN cylinders. Not heard of first stage failure. K

That is why, @NYCDiverBlue I strongly suggest you opt for DIN regs.

Don't be deterred by the old school Yoke being the 'standard' where you dive. I rent my back tanks and even in Yoke-infested Australia, I only ever came across one shop that did not have a tank with removable insert to make it DIN. So I used my yoke-to-DIN adapter only once. DIN is a more secure, higher pressure rated connection, and even if you do not dive hp cylinders, the O ring is on the reg side and well trapped, instead of relying on the O ring of the tank in generally questionable condition. Plus it makes for a much more compact setup. Look at the pony pic from above, now imagine this whole yoke thing hanging off that. The reg would be twice the size! Oh my.

 

[chillyinCanada]

I've been diving the same regulator set and no other, since the outset of my diving. All my other gear has changed a time or two.

As was said above and as I have always said:

Take care of your gear and your gear will take care of you.

My diving is always done on extended trips out of the country.

I often travel with O rings but have very rarely needed to use them. Regardless, they have make the dive guide staff happy for a gift to go along with their tip.