Intermediate Pressure Guage

[halocline]

That's close to mine. The IP holds at 110 during a venturi free-flow so I'm guessing that an MK17 easily qualifies as a high-flow reg (it is well known that the MK25 is legendary in the high-flow category). My second stage is a G250...

I would not be confident that you're getting an accurate reading of the IP during free flow if you're using an IP gauge that's connected to the LP inflator hose. As I mentioned, I strongly suspect that there are venturi forces within the IP chamber (like a turret) and hoses themselves while air is flowing. This means, for example, that strong flow out an LP port to a 2nd stage could cause a venturi force lowering pressure in the LP port that the LP inflator hose is attached to. Take a MK2, hook up an IP gauge as we're discussing, press the purge, watch the needle drop maybe 10 PSI. Do the same thing with a MK10, MK15, or even MK20, both much higher flowing regs, and the IP gauge will drop substantially lower. There's no way that the flow is less in those regs, even though if the pressure is lower in identical volumes (same hose/2nd stage configuration) then lower pressure means less flow.

All those regs will recover really fast, but the way the needle swings is unexplainable to me other than with this venturi idea.

 

[scubafanatic]

I can answer that as I used to manage a dive center, that is now a pretty good player in the online sales arena, and we stocked those IP gauges. Rarely sold any, and when we did it was usually to staff or a local instructor. Now I own a dive center and I do not stock these gauges. Why? Because no one ever asks for one. I demonstrate their use and value in my Advanced and Master diver classes, as well as Leadership, and use it at my local dive sites. Yet no one asks for one.

I have 2 such gauges (an analog one and a fancy 'digital' one) and I use them to check on IP settings after dive shop servicing, and to check regs out before trips. I don't bring IP gauges on trips, as I can't fix regs out in the field anyway, and odds are any reg that checks out 'OK' before a trip is likely to last with no issues for another week (typical trip length).

I agree owing an IP gauge (or TWO) is pretty 'geeky', (and I'm an admitted gadget guy) so I can certainly imagine sales volumes are pretty low.

 

[guruboy]

I bet most OW/AOW divers don't even know they exist. I only know because of this board.

 

[chrpai]

I bet most OW/AOW divers don't even know they exist. I only know because of this board.

Of course not! Regulators are critical life support equipment. Should buy only the very best, most expensive and have it serviced annually by certified technicians. In fact, never take the front off of a 2nd stage to know what it looks like inside. You don't need to know that.

 

[driftwood]

I bet most OW/AOW divers don't even know they exist. I only know because of this board.

Welcome to the dark side.

I believe that the more divers know about how his/her equipment works the better off/safer all of us are in the water. Too bad that not more time is spent in training on the nuts and bolts of analyzing your gear before there is a problem.

I dive in water that is tough on gear due to a lot of suspended solids. Spring Lake may have great vis, but you don't want to soak your gear in it for an extended period of time. Because of those conditions, I keep my BC inflated between dives and check the "health" of my first stage about once a month.

I think it's great that evad found an IP gauge at a lower price than my lazy search turned up.

 

[chrpai]

I dive in water that is tough on gear due to a lot of suspended solids. Spring Lake may have great vis, but you don't want to soak your gear in it for an extended period of time. Because of those conditions, I keep my BC inflated between dives and check the "health" of my first stage about once a month.

What first stage do you have? Is it environmentally sealed?

One of the things I like about my DRIS 27lb wing is I can easily remove the inner bladder and clean/inspect thoroughly. I've never dove spring lake but I know with Lake Travis the darn sediment gets everywhere and I spend quiet a bit of time soaking and rinsing to get everything clean.

 

[redacted]

I don't worry too much about organic matter as occurs in Spring Lake and many of our other local lakes. I'm not sure if I am making a mistake but so far (15 years in the river and the lake) I have not had any problem. I do lots of soaking after salt water dives, but little to none after fresh water. I finally did a rebuild yesterday on a Mk7 that has been my primary reg for the last 2 years and had not been serviced (other than dynamic o-ring lube) for over 5 years. The IP was finally climbing out of spec range and causing a 2nd stage to FF. I did a couple days of soaking and a detergent cleaning but did not even bother with the acid and the US cleaner. The only special care my wing gets after the lake is a hosing off to get rid of the snails and weeds that inevitably get trapped. They can get a little nasty after a few days.

 

[driftwood]

What first stage do you have? Is it environmentally sealed?

One of the things I like about my DRIS 27lb wing is I can easily remove the inner bladder and clean/inspect thoroughly. I've never dove spring lake but I know with Lake Travis the darn sediment gets everywhere and I spend quiet a bit of time soaking and rinsing to get everything clean.

Becky and I both dive old Zeagle DS IV's, so no environmental seals.

The problem with Spring Lake is the TDS's from the springs. They raise the specific gravity of the water to where it is closer to sea water than fresh water. You get an awful lot of calcium in the water and all the other minerals that make up the limestone. If you leave metal in the lake too long, say 6-9 months, the combination can be fairly nasty. On the plus side, there are so few organics in the water coming out of the high pressure springs, Deep Hole, that you can drink it without fear.

 

[ianr33]

Yo, any mods awake? How many times can I "like" a post???

Depends how many accounts you have.

 

[halocline]

Becky and I both dive old Zeagle DS IV's, so no environmental seals.

The problem with Spring Lake is the TDS's from the springs. They raise the specific gravity of the water to where it is closer to sea water than fresh water.

I have heard that there is a high mineral level in the water, but I'd be surprised if it's anything like seawater. Seawater has a specific gravity around 1.025. What's spring lake? I think the hard water in Austin and San Antonio is something around 300 ppm TDS, where sea water is around 30,000 ppm. Or do I have something wrong here?

At least I know my weighting in Spring lake is more-or-less fresh water, not salt water.