Posted by Jim on January 01, 2002 at 22:20:03:
In Reply to: Re: Yoke vs. DIN posted by Steve on January 01, 2002 at 20:58:09:
The suggestion that DIN is better than yoke is a littel misleading. DIN originally was developed in europe. The DIN valve, since it screws directly to the 1st stage can contain higher pressures than the yoke type 1st stage. With the introduction of high pressure tanks (~3500 PSI) tanks in the US, DIN valves became necessary. Unless you are diving with high pressure tanks a DIN valve is unnecessary.
It can be said (and it has been in this thread) that DIN is better because:
1) DIN can contain higher pressures
2) DIN are less likely to blow O-rings
3) A DIN 1st stage can be converted to a yoke, but a yoke can not be converted to a DIN.
However, most places still use "K-valve" tanks (the standard one we are all familiar with) so the addition of an adapter to use your DIN 1st stage to a standard tank is necessary. Also, many shops do not cater to DIN typs tanks, so if you have your own another adapter allowing a DIN tank to be filled by a yoke fitted compressor is necessary (and will limit the fill to ~3000 PSI).
Bottom line, is a DIN necessary for your diving habits? If you are a "standard" recreational diver you will gain little if any benifit from a switch to a DIN outfit.
For your Octopus question. It's not as simple as can any regulator be fitted to a particular brand 1st stage. The purpose of the 1st stage is to reduce tank pressure to 2nd stage (regulator) operating pressure. The pressure that comes out of the LP (low pressure) side of the 1st stage is fairly well set at the manufactur (there is some room for adjustment). The pressure requirement for a 2nd stage is also set from the manufacturer. So, a 1st stage may reduce tank pressure to 180 PSI but a 2nd stage may require 240 PSI for proper operation. This can be the case even within the same manufacturer! Additionally, not all 2nd stages use the same size fittings to screw into the LP port of the 1st stage (this is done by manufacturers to ensure that only their brand of 2nd stage is used with their 1st stage). Typically this practice of various screw sizes for LP ports isn't used much anymore.
So, the answer to your question. Yes and no. Take your 1st and 2nd stage to a reputable dealer and ask. You are more likely to get good, informed information from a factory authorized repair technician then from a salesman. Even in a factory authorized repair shop, the sales guy (or gal) may not know, talk to the technician himself. If you still have questions contact the manufacturer and find out if the specific 1st stage will work with the specific 2nd stage you are trying to put together.