What is up with this G250HP?

[pescador775]

It's a new G250HP which I have fine tuned. It is connected to a US Divers SEA with 1/2 inch hi-flow hose. The 2nd stage functions normally until the hose nut is tightened. Tightening the hose nut with a wrench is followed by a slight free flow from the G250HP. If the nut is backed off slightly the 2nd stage freeflow stops. Free flow can also be stopped by turning in the adjustment knob 1/2 turn. I checked the dimensions of the various parts and can find nothing incompatible. There does not appear to be any twisting of the air barrel when the nut is tightened. Any ideas?

 

[JBRES1]

Have you tried another hose ?

Could the hose connection be pushing on the adjustment slot head ?

What pressure did you set the first stage to, and to what pressure is the second stage cracking at ?

Jim Breslin

 

[tfsails]

Try tweaking the orifice adjustment about 1/8 turn clockwise. That might stop the freeflow. It'll also make the reg a tad harder to breathe on but not appreciably so. If you don't know what I'm talking about, take the reg to a pro and let him do it for you.

 

[redacted]

I suspect the housing (barrel) is moving a bit in the case when you tighten the hose nut. Try removing the front cover and then see what happens (if it still starts a FF). My 03/00 G250 HP schematic shows an o-ring sandwiched between the case and the jam nut. It is not being used to seal anything so I suspect it is the cushion to distribute the force evenly when the jam nut is tightened.

The Scubapro part # on that o-ring is 01.050.193 which I measure out on their size chart as a 2-111.

 

[pescador775]

All, the hose nipple is not contacting the orifice, there is plenty of clearance, at least 1/16 when the hose is unpressurized and much more when pressure is applied. The regulator IP is 140. I have not tried another hose but as far as the 2nd stage's view of this, it only knows that it is connected to a standard hose end fitting and standard pressure, period. AWAP is probably right but I need to provide some additional info. Firstly, I do not have a service manual for this particular regulator so there is some guesswork. Typical construction of a G250HP includes a plastic "air barrel" which is threaded and held fast to the case with jam nuts. My 2nd stage is somewhat different. Instead of a jam nut, on the inlet side there appears to be a metal coupler. This could also be described as a "union" or "adapter". In other words, the hose nut screws onto this metal piece, not directly to the barrel. At this moment, I don't know how the coupler is connected to the barrel, probably it is threaded to the plastic the same as a jam nut. The base of the coupler is configured with the same form and appearance as a jam nut and uses the same SP special wrench. I will try to provide some pics later. I adjusted the regulator to a satisfactory performance, just. However, it was a time consuming process of adjustment, torquing the hose and repeating, lots of repeating. It occurred to me, that if I did it again, I would use the in-line adjustment tool but instead of threading the tool on finger tight, would torque it down good. So, whatever compression or twisting that might be occurring would be accounted for in the initial adjustment.

The barrel appears to be composed of several pieces, a metallic grey section which contains the demand lever and end pieces which are black in color. My general observation is that there are plenty of opportunities for torsion misalignment. However, I won't be disassembling this contraption without a manual.

When received from Leisurepro, this G250HP was connected to a MK25 with IP of 175 psi. I swapped out the piston reg, adjusted the IP and use it for a back up. It is now connected to a 10 year old G250HP which breaths excellent, better than the new reg. Adjustment of that reg was pretty much routine, without any particular issues.

 

[Couv]

Hello Pesky,

I am not a fan of any Scuba Pro plastic seconds, but I may have some files you might find helpful.

PM me with your email address and I will shoot them to you.

Edit: My guess is this. Because you are dealing with a plastic air barrel, when you put the final torque on the hose fitting it is causing a slight misalignment of the poppet/orifice interface. You might want to try another poppet
seat also.

Incidentally, a slight free flow with the adjustment knob all the way out (but able to stop when adjusted in) is how I like to keep mine adjusted. I know it will have min cracking pressure and when stored puts very little pressure on the soft seat.

Here is a link with SP G250HP repair and t/shooting manuals.

http://www.frogkick.dk/manuals/scubapro/Manuals/2. Stage/

Couv

 

[pescador775]

You fellows have been very kind. However, before downloading anything I should mention that I have about 2 pounds of company authorized literature on the G250HP including step by step repair manuals. Nevertheless, none of this material deals with the regulator which is the subject of this thread. Evidently, it was the last (failed) attempt before Scubapro gave up and transitioned to a metal air barrel and redux of a 20 year old design; a wise move considering that they were unable to extract reliability from the plastic stuff. SP has a history of weak, frangible regulators, screws breaking, turrets flying, plastic fracturing, seats blowing out, nuts popping off, etc, and it is never the company's fault, it's those darn technicians. I count myself lucky sofar. Another smart move and a belated attempt to face reality was to produce the MK17. I would never again pay that kind of money but the product is nice. If Ace Hardware were selling the MK17/G250V the price point would be about $250-300.

That guy on the other thread who is whining that he can't afford anything much over a buck but wants Scubapro. Heck, he could have the Scubapro second stage for 200 dollars on EBay. That is the heart of the regulator; the first stage is generic, any of them will do. He could call Island Scuba and buy two really nice first stages for $100 and use them for 20 years without ever going back to a dive shop for service. As far as the G250V, he would need a few O rings and a seat after 5 years or so. By that time, he would be out of grad school and pulling down 100 dollars/hour.

 

[Couv]

Pesky,

Some sharpie put the air barrel in backwards then put the jam nut on backwards and forced the adjustment knob over the inlet.....just kidding, but I am looking forward to seeing pictures of this aberration.

couv

 

[Nemrod]

Try tweaking the orifice adjustment about 1/8 turn clockwise. That might stop the freeflow. It'll also make the reg a tad harder to breathe on but not appreciably so. If you don't know what I'm talking about, take the reg to a pro and let him do it for you.

What sort of pro?--a scuba pro? Pesky is a pro. You wouldn't be meaning the guy with the tongue ring down at the lsd shop would you?


N