Bands to hold purge valve open

[Hatul]

Are there any commercially available bands to hold the purge valve open on the 2nd stage to decrease the wear on the valve seat.

I have two old Oceanics with jerry-rigged elastic bands with corks -- doesn't look so good in my Rolls:cheeky:.

Adam

 

[Fishpie]

There isn't (to my knowledge) any commercially available purge presser.

Individual companies had devices for their own regs.
Dacor had a PBD purge button depressor clip on and a sliding putton on a faceplate.
Sherwood had a spring loaded button on faceplate.
Scubapro had a key and key fob for Pilots, Air 1, 108, 109

.....your rubber band and cork will work better than the majority of the manufacturers devices.

 

[Leisure Proski]

Hi,

Unless your regulators are over 30 years old using something to depress the purge button to "Save Your Seat" is a myth. Almost all manufactures went to a silicone material in the LP seat of their regulators in the 70's. The quality of the rubber is so much better then neoprene (which is the old material used) that the purge depressing devise ended. Not only did it end due to better materials, but it closed the back door of the regulator to corrosion.
The CGA (Compressed Gas Association) advises industry on gas purification requirements. The CGA recommends that breathing air CGA7.1 Grade E or better have a dew point of -65° F. Dew Point the point that moisture will form when the temperature of the air drops. Think of what that due point means you have to drop the temperature of the air to -65° F before you can detect any moisture. That is super dry air.
That dry of air dehydrates us when we breathe it. We get cotton mouth from diving. Dehydration promotes decompression sickness. So why does it need to be so dry? To care for the integrity of the breathing mechanism and cylinder, what causes corrosion? Oxygen and moisture causes corrosion, increase to concentration of either and you increase to promotion of corrosion. With the higher oxygen content in compressed air we have increased one of the two causes of corrosion.
Allowing ambient moisture to enter the internal mechanism of your regulator will do more damage to the regulator than “Saving the Seat” Get rid of the cork and rubber bands and get rid of the moisture in your regulator. If this tip makes sense or you want more explanation feel free to contact me in the future.

Sincerely,
Leisure Proski

 

[Fishpie]

Guess we'd better disable all those Atomic 2nd stages that pull the seat away from the orifice when unpressurized.

 

[Zung]

I agree that the value of the "Save-A-Seat" thing may be a bit overstated.

My main G250 slept in a closet for nearly 10 years without any special treatment while I watched the kids grow. We started diving again last year, and I compared it to the kids' freshly serviced G250's, and mine breathes every bit as good.

Btw, all of them have cracking effort in the 1 inch range.

 

[Hatul]

I turned to keeping the purge valve open in storage, after my old Oceanic Alpha octo started free-flowing. This second stage is not adjustable and is connected to my new Atomic ST1. I checked the IP of the ST1 and it's 130 psi, so that's not the explanation. Also the Alpha was serviced less than one year ago.

It may be a coincidence but after the purge valve was kept open the free-flowing seems to have stopped.

Adam

 

[Hatul]

I agree that the value of the "Save-A-Seat" thing may be a bit overstated.

My main G250 slept in a closet for nearly 10 years without any special treatment while I watched the kids grow. We started diving again last year, and I compared it to the kids' freshly serviced G250's, and mine breathes every bit as good.

Btw, all of them have cracking effort in the 1 inch range.

Isn't the G250 adjustable? My Oceanic Alpha octo is not adjustable was set with high cracking pressure, which I believe implies a lot of pressure on the valve seat.

Adam

 

[Fishpie]

Here's a tip that sometimes works for leaking 2nd stages that have been in storage of a bit.

Take off the offending 2nd stage (from the hose) and slosh it around in a bucket of fresh water with the purge button depressed.....it'll get rid of any dried salt that might be encrusted around the orifice causing the slight ff.

 

[redacted]

I use a loop of bungee and a plastic pour cap from a 1/2 gal of drinking alcohol on my Scubapro R190s (similar to Oceanic alpha). I filed a couple grooves in the pour cap to engage the bungee. But that is little different from your rubber band and cork.

I store most of my regs with the purge slightly depressed. Only ones I don't are my 2nds with the seat saver feature and my D-series regs (real light spring and no easy way to depress the purge in storage. All my old Scubapro metal 2nds came with a purge depressor for use in storage, including the old Pilot. But I don't think the manufacturers were pushing annual service back then.

 

[halocline]

Hi,

Unless your regulators are over 30 years old using something to depress the purge button to "Save Your Seat" is a myth. Almost all manufactures went to a silicone material in the LP seat of their regulators in the 70's. The quality of the rubber is so much better then neoprene (which is the old material used) that the purge depressing devise ended. Not only did it end due to better materials, but it closed the back door of the regulator to corrosion.
The CGA (Compressed Gas Association) advises industry on gas purification requirements. The CGA recommends that breathing air CGA7.1 Grade E or better have a dew point of -65° F. Dew Point the point that moisture will form when the temperature of the air drops. Think of what that due point means you have to drop the temperature of the air to -65° F before you can detect any moisture. That is super dry air.
That dry of air dehydrates us when we breathe it. We get cotton mouth from diving. Dehydration promotes decompression sickness. So why does it need to be so dry? To care for the integrity of the breathing mechanism and cylinder, what causes corrosion? Oxygen and moisture causes corrosion, increase to concentration of either and you increase to promotion of corrosion. With the higher oxygen content in compressed air we have increased one of the two causes of corrosion.
Allowing ambient moisture to enter the internal mechanism of your regulator will do more damage to the regulator than “Saving the Seat” Get rid of the cork and rubber bands and get rid of the moisture in your regulator. If this tip makes sense or you want more explanation feel free to contact me in the future.

Sincerely,
Leisure Proski

Thanks for the lesson, the only problem is that nobody uses silicone seats, I suspect mostly they're EPDM, probably some nitrile. Are you thinking of diaphragms? The other thing is that you're not going to corrode your regulator by storing it "unsealed" from ambient air due to the seat saver. Maybe you're forgetting that there is another opening to ambient, specifically the mouthpiece. If you're talking about humidity migrating up the hose from the 2nd stage to the 1st through the open LP valve, sure that's possible but extremely unlikely to cause any problems.

Oh yeah, one other thing, I think some of my regs are over 30 years old. But the funny thing about it is, they use the same seats as current regs. And, they've all been exposed to ambient humidity for those years.