awap:
I wish I were as comfortable with SP as you seem to be. The speculation that it may have involved a dropped tank was pure speculation. There was no evidence of such an incident. I guess I never was fully comfortable with the explanation of overtorqueing by repair techs with the Mk20. I'm still doubtful because the body is failing with that longitudinal crack rather than the threads on the connection. And it seems to be a problem only with the Mk20/25 and not with the older BPs of similar design (different thicknesses and different manufacturing processes??)
I drove my explorer with Firestone tires and I'll continue to dive my SP BPs. But I'm hoping the CPSC takes another hard look at what is going on here. I do not trust a manufacturer to put the consumers well being ahead of his profits - especially once it is off the drawing board and in production.
Well on the one hand they - the people with the reg itself who are most familiar with the situation - are speculating that it was dropped instead of speculating that it is due to a materials flaw - as are those who really know nothing about it. Maybe it's just me but one category of speculation seems to be more reliable and more responsible than the other.
The Mk 20/25 design has been around for well over a decade and tons of them have been produced. Out of that there have been very few failures from any causes and none have failed in the water. The fact is that due to the nature of the internet, every failure will be brought to the public's attention regardless of the cause.
SP tends to take a lot of heat for regulator design "flaws" when in truth their committment to long term parts support and service ensures their regulators stay in service when many other brands would have long since been consigned to paperweight status. In addition, many SP regs are used in extreme diving situations not seen by many other brands. Despite rumors, etc, they remain popular with the technical diving crowd - a very particular bunch over all who use their gear hard on a regular basis in demanding conditions.
If there is a flaw in the design, it would be the nature of the basic layout where a greater amount of leverage can be exterted against the yoke retainer and the body of the reg where the yoke retainer is anchored. Ie: lettign the tank fall forward off a bench while gearing up is going to result in the unit impacting on the regulator itself. All that energy has to go somewhere and not all of it goes into the boat deck. Is SP at fault for failing to design a reg that a moronic diver can safely drop on it's head? Apparently.
I don't think there is a flaw in the materials, manufactuer or design of the body itself as brass is a well nown material with 50 plus years of use in scuba regulators. The Mk 20/25 has lightening cuts in the body, but they are on the opposite side of the regulator. The differences between the Mk 20/25 and the earlier Mk 5, Mk 10 and Mk 15 are not in that area of the body. In my opinon, that type of failure is then by default the most likely the result of how the particular regulator has been used and/or serviced.
And I have to say in the 20 plus years I have been diving, the average entry level diver, to state it nicely, appears to be somewhat less committed to proper care and treatment of high pressure tanks and regulators that they were 2 or 3 decades ago.
The fact remains a diver is responsible for the proper maintainence and pre-dive inspection of his or her gear and a quick visual inspection for an incipient crack, a leak check on the surface and a bubble check just after submerging would catch 99.99% of any similar cracks -what ever the cause. Consequently, I have no problem diving with a Mk 20 or Mk 25 (let alone 50 plus year old vintage equipment) because I take reasonable care of my eqipment and I do a proper pre-dive inspection prior to each dive. So in effect, the control of the situation lies with me.
