old scubapro

[Hzracing]

There are some significant differences:

1. If your faucet leaks you are not at risk of dying or injuring yourself.

2. Your faucets also operate at something far less than 100 psi, while your first stage operates at anywhere from 2250 to 4350 psi with a full tank and your second stage operates at 120-145 psi.

3. A small scratch on a mating surface of a faucet is no big deal. In contrast, for example, if you scratch the inside of your Mk 10 picking out the HP o-ring, it will leak and the only fix would be to replace the entire first stage body, if you can even find one - and in any event it would be cheaper to replace the first stage.

4. Using the wrong o-ring in a faucet is at worst an incovenience. Using the wrong o-ring in your regulator can result in catastrophic air loss at depth.

5. There are also longer term problems that can result from improper techniques and/or not following specific procedures and/or torque limits such as parts cracking, parts becoming stuck together more or less permanantly or, worse, coming apart mid-dive.

None of this is to say it's overly "hard", but it is critical that you know what you know what are doing and that you do the job right.

x2, I've seen all of these on amateur repaired regs, Is your life worth saving $20 - $50 bucks??

 

[Luis H]

I was referring to the early models with one 3/8" HP port and only 2 LP ports. They are ok on pony bottles etc, but do not work all that well as a primary regulator due to the odd HP hose size or adapter needed and the limited number of LP ports. If it also has a low pressure 2250 psi yoke that is another problem, although that one that can be rectified with a new yoke.

I do agree with you that the later MK 5's with heavy 3300 psi yokes, two 7/16" HP ports and the 4 or 5 LP port turrets are still excellent regulators. I own 3 or 4 of those.

A Mk 5 with the newer concave seat performs well enough at high tank pressures with 125-150ish SCFM flow rates which are more than adequate for any recreational purpose. However performance falls off at lower tank pressures and that is probably the only practical thing they give up to a Mk 10 or newer regulator.

Personally, if someone goes with a newer Scubapro regulator, I almost always recommend the Mk 17 as it does offer significant advantages over the older and newer piston designs.

Thanks for the response.

I guess I didn’t even think about the 3/8” HP port being a disadvantage, since most of my pressure gauges are 3/8”.

I always considered the flow rate on this regulators to be outstanding at any tank pressure (especially if you compare it to a diaphragm first stage), but I will take your word that the newer SP are better in that respect. Actually, IMHO high performance diaphragm first stage also provide more than sufficient flow rate for most circumstances (and they do have some other advantages).

The opposite side of the coin; lower performance at lower tank pressure was not always considered a bad thing. At one time that was considered a good advance low air warning. Compared to some of the other regulators of the time, the Mk 5 ruined that warning feature.

Taking about diaphragm first stages, I can see why your preference for the Mk 17, but I find it interesting / ironic, that regulator coming from Scubapro. I am not specifically familiar with it either, but I have seen the parts diagrams.

I have always liked Scubapro, but I guess if I am going to pick my favorite diaphragm first stage I would have to pick the US Divers (Aqua Lung) Conshelf or Titan. I think there is something to be said for a first stage that has been around for over 30 years basically unchanged (and it shares all its internal parts with my Royal Aqua Masters).

 

[superstar]

How about a brake job including the master cylinder, or maybe a carberator rebuild.

Both are a bit more involved than a Scubapro reg. The big difference is that GM, Ford, etc. is willing to sell you parts and tech info so you can do it yourself.

 

[redacted]

Both are a bit more involved than a Scubapro reg. The big difference is that GM, Ford, etc. is willing to sell you parts and tech info so you can do it yourself.

Depends a bit on which reg you are talking about. My old metals are fairly simple. The HP o-ring takes a bit of care and it's best to watch the torque on the turret nut and yoke nut but the rest is pretty easy. The R109 with just 2 o-rings is my favorite. But last weekend I brought my Mk20/G500 out of retirement for my grandaughter. Replaced every o-ring in thr rig and upgraded the piston. Then I just sat back and marveled at the pile of used o-rings and plastic pieces. It is a great breathing reg but it is a good thing o-ring are reliable.

My understanding is that Scubapro only sell parts to authorized dealers but does not restrict the resale of those parts other than the over-the-counter requirement in the dealer agreement. It is up to the shop as to whether they will sell parts to customers or not. You just need to find those shops that would rather have your businesws stay with them rather than go elsewhere.

 

[DA Aquamaster]

My understanding is that Scubapro only sell parts to authorized dealers but does not restrict the resale of those parts other than the over-the-counter requirement in the dealer agreement. It is up to the shop as to whether they will sell parts to customers or not. You just need to find those shops that would rather have your businesws stay with them rather than go elsewhere.

In the US Scubapro does not restrict pricing of parts and dealers are free to charge what ever they want for them - anywhere from below cost to as much as the customer will tolerate.

However, if a dealer started selling parts directly to customers or non-SP dealers, SP would have a serious issue with that. In fact Scubapro prefers that any parts returned to the customer be rendered unusable first (cutting o-rings, etc). I personally do not do that as they are the customers parts, not mine and I don't feel I have the right to destroy someone else's property.

 

[redacted]

In the US Scubapro does not restrict pricing of parts and dealers are free to charge what ever they want for them - anywhere from below cost to as much as the customer will tolerate.

However, if a dealer started selling parts directly to customers or non-SP dealers, SP would have a serious issue with that. In fact Scubapro prefers that any parts returned to the customer be rendered unusable first (cutting o-rings, etc). I personally do not do that as they are the customers parts, not mine and I don't feel I have the right to destroy someone else's property.

I've seen the parts lists with the "MSRP" which I assume is a 100% markup from dealer cost. Are the restrictions/preferences you refer to part of the written US dealer agreement or is this passed on in some other manner like training sessions?

 

[DA Aquamaster]

Taking about diaphragm first stages, I can see why your preference for the Mk 17, but I find it interesting / ironic, that regulator coming from Scubapro. I am not specifically familiar with it either, but I have seen the parts diagrams.

I have always liked Scubapro, but I guess if I am going to pick my favorite diaphragm first stage I would have to pick the US Divers (Aqua Lung) Conshelf or Titan. I think there is something to be said for a first stage that has been around for over 30 years basically unchanged (and it shares all its internal parts with my Royal Aqua Masters).

Having been a confirmed SP piston reg fan since the early 80's I found it quite ironic that I prefer the Mk 17 to anything else currently available.

Whether you look at the classic balanced piston design or the classic balanced diaphragm design, it's hard to stray too far from the basic design and if you do so, it needs to be in the right direction and for a specific pupose. In Scubapro's case they moved to the use of a bushing system in the Mk15/20/25 to allow tighter tolerances to be maintained over the life of the regulator in order to allow 300 bar (4350 psi) service pressures without encountering problems with HP o-ring pinching, which was a problem in some cases with Mk 5's, Mk 10's, etc at pressures over 3000 psi. I see signs of this on a couple Mk 10's every year even when used on 3000 psi tanks and I suspect these regs are just a little on the loose side in terms of tolerance, so the design change on the Mk 15/20/25 does have some merit.

Similarly, SP went back with a larger diameter piston head on these regs and in essence reverted back to the Mk 5 design in that regard. The downside is the slightly larger, longer and generally bulkier size.

The big killer though, in my opinion, was Scubapro dropping the SPEC system and adopting the TIS system for freeze protection. SPEC was messy to service, required careful packing for full effectiveness and with all but the last boots often required topping off in mid season if you dove a lot. But when maintained properly it was extremely effective in preventing first stage freeze ups. In contrast the TIS system works well on the Mk 2 and Mk 16, but is only marginally relaible on the Mk 25 with it's much higher flow rate and the proximity of the LP ports, swivel cap, piston and ambient chamber to each other.

If Scubapro had just switched to a O2 compatible filler for the SPEC system, like Christolube, (or if they would re-introduce the system on the Mk 25 as an option) the Mk 25 would be a very credible cold water regulator. But they didn't and it's not.

SP has also toyed with alumium, aluminun/stainless steel and titanium in the Mk 20 and Mk 25. The aluminum versions invariably encounter problems with dissimilar metals corrosion and titanium compromises the ability of the reg to handle high percentage O2 mixtures in addition to being sinfully expensive. The Mk 25T has snob appeal and light weight, but offers little of real vaue over the brass Mk 25.

So all in all over time SP has moved away from designs such as the Mk 5 and Mk 10 that offerred good performance in a simple and very reliable package (sort of what the AK-47/AKM/AK-74 family is to military small arms) and has evolved to the more complex, more expensive, better performing but less reliable Mk 25. In my deep, cold water diving opinion the benefits have not been worth the compromises. Reliability is very, very high on my list, particularly on a cold, deep deco dive.

I share your warm regard for the Conshelf series as they are simple, reliable and have proven to be very durable over time. They are to diaphragm regs what the MK 10 is to balanced piston regs - basically what the AK-47 is to the assault rifle. The Mk 17 has impressed me as it builds on this robust design, adds performance improvements in both flow rate and response time, adds an excellent seat alignment system and a truely exceptional cold water package with attention to both heat transfer and a fully sealed ambient chamber. In short, it is takes the classic balanced diaphragm design and moves it purposely in the right direction. SP took a lot of time desigining the Mk 17, but they did a good job with it and got it right.

At this point I am guessing that the Mk 17 or it's decendents have a lot more life left in them than the Mk 25. Personally, I see nowhere for the Mk 25 to usefully go other than perhaps exhanging some of it's uneeded and excessive flow rate for a lower parts count and improved reliability - and in that case you'd be very close to having a modernized and upgraded Mk 5.

 

[superstar]

It makes me wonder why if the MK2 and MK5 are so reliable, (I have both) why don't all the tech divers use them. On the conshelf, I was recently given one that was put away wet in the bildge of a sailboat 10 years or so ago. It was green and nasty, and it worked. Thats reliable.

 

[guam7375]

ok, so my friend has a scubapro reg setup, and it hasn't been used in several years. My shop said it would cost 100 to service, but they don't sell scubapro. I am thinking of finding scematics online and then letting him service it himself, he's tech savvy and good at this kind of stuff. Anyone ever do this themself? Is there a way to become a "certified" technician if not affiliated with a shop?

Which scubapro is it?

 

[mictrik]

Well that all may be very true; but i bet a careless tech sometimes even an experienced tech can and have also damaged regulators during service ( happened to me). Now the question is how many will own up and say "well we damaged your reg during service so we will replace it"; fat chance! I take my time and think about what i do and so far my regs function perfectly. In fact they probobly function better when I service them because i am willing to tune it to the edge of performance vs freeflow. I know that i can re-tune in the field if I wish, but a dive tech will not be there with me to tune my second down from free flowing so they are justifiably less inclined to tune for max performance. There are advantages to learning how your regulator works and maintaining it yourself other than monetary savings...