Pressure on the Priority Valve????

[Hoosier]

I would try adjusting the spring tension too. Mine worked fine for the first couple hours I owned it then loosened up by over 1000psi. Been steady at 2000psi ever since (150 hours use). I guess the spring broke in. Might have happened here.

Or he could swap it with priority valve #1 and see if that one holds pressure.

Plenty of parts to play with and deduce the source of the problem.

Yes, I still remember what you advised in other thread..


Any comment on this question:

Question: When I set up the breaking pressure on Priority valves, 2nd priority valve must be lower than the pressure on the final priority valve on HF appliance?

 

[rjack321]

Question: When I set up the breaking pressure on Priority valves, 2nd priority valve must be lower than the final priority valve on HF appliance?

I don't think so. Why? Could go either way IMO without much affect.

Your first priority valve is only doing you some good at startup. Before all the chambers fill up you get increased pressure sooner in the coalescer and get a little bit more moisture to drop out before the gas enters the first filter.

After the final chamber reaches its target pressure the final PV can be higher or lower than the first. Doesn't make a huge difference what pressure the 13x in the HF is run at.

Of course PVs don't do anything once the tank pressure is greater than 2000 or whatever they are set at.

So if you had only one PV you'd have a few more minutes of higher humidity gas enter filter #1 before the moisture seperator started being effective. The earlier PV helps get the seperator to an effective operating pressure sooner. In a 2 PV system the latter PV does little if anything unless its set higher than PV 1, in which case the final moisture seperator gets a tad more effective once the final chamber fills up.

 

[pescador775]

A word about shelf life; I'm curious as to where this concept originated WRT filter media. I mean, the filter chemicals are not like lettuce or spinach. As far as I can tell, the chemicals only degrade when exposed to the atmosphere. They should last a long time if sealed in a container, including a filter canister.

 

[rjack321]

Poor choice of words. I meant installed in the chamber with potentially humid gas sitting around it.

Sealed in a package I would use a 2yo filter. 4 or 5yo? probably not, I can't for sure say there's degradation of 13x or AC effectiveness but its just not worth it for the price I pay for pre-packed filters (18" tower - $45 for triplex filtration). I keep my bulk media in nalgene bottles and try not to buy more than a year or two's supply. Ditto for synthetic oil.

 

[pescador775]

Soft packaging makes me a little skeptical and I usually double wrap those. However, media contained in a plastic, sealed bottle should be good for a long time. Years ago, media was sold in "paint cans" and the 13X would go bad in a year or two. Charcoal will last indefinitely but if exposed to atmosphere will absorb moisture, bake in oven at 350 F for a few hours to drive off moisture. I bought 5 gallons of activated charcoal for thirty bucks on EBay and it works well. As I reported on Scubaboard, tests of 13X show it will go dead in 24 hours when exposed to atmosphere. However, baking at 500 F for six hours will almost completely regenerate the stuff. Place a bag of color indicating gel in with the 13X. As to synthetic oils, the shelf life is 30 years. Some bottles sold by Nalgene are made of Lexan which is composed of phosgene and bisphenol. These and other plastics containing bisphenol are reported to be poisonous to humans if liquids are drunk from the plastic bottle. (Those who contend that the material is dangerous are degreed researchers in epigenetics).However, the manufacturer disputes this. Otherwise, outside of applications for foodware, lexan seems to be useful in many ways.

 

[rjack321]

Good idea about tossing a moisture indicating disk in with my bulk 13x, thanks.

 

[Hoosier]

Soft packaging makes me a little skeptical and I usually double wrap those. However, media contained in a plastic, sealed bottle should be good for a long time. Years ago, media was sold in "paint cans" and the 13X would go bad in a year or two. Charcoal will last indefinitely but if exposed to atmosphere will absorb moisture, bake in oven at 350 F for a few hours to drive off moisture. I bought 5 gallons of activated charcoal for thirty bucks on EBay and it works well. As I reported on Scubaboard, tests of 13X show it will go dead in 24 hours when exposed to atmosphere. However, baking at 500 F for six hours will almost completely regenerate the stuff. Place a bag of color indicating gel in with the 13X. As to synthetic oils, the shelf life is 30 years. Some bottles sold by Nalgene are made of Lexan which is composed of phosgene and bisphenol. These and other plastics containing bisphenol are reported to be poisonous to humans if liquids are drunk from the plastic bottle. (Those who contend that the material is dangerous are degreed researchers in epigenetics).However, the manufacturer disputes this. Otherwise, outside of applications for foodware, lexan seems to be useful in many ways.

I think there is a little bit different opinion on regenerating the stuff..

 

[rjack321]

Not regenerating after use. Reactivating after its been stored a bit too long in an opened container and has hence absorbed its ~15% by weight of water already. I actually think my last repack is compromised since the time+temp has been way shorter than it should until moisture breakthrough.

I won't hesitate to bake some of the moisture out of what's left of my 13x supply before repacking my next primary filter.

 

[EastcoastdiverLLC]

Hoosier,

I spoke with Mike Casey on the priority valve issue. My is set up to open at around 2200 psi and doesn't close until the supply presure drops to a little over 1000. He says that is fine and well within the specs.

Gary

 

[pescador775]

I've never seen a back pressure valve do that, stay open until the pressure drops by half. All my valves are military surplus and they open and close within about a 200 psi range, the same as a relief valve. Sometimes, the definition of open and close is fuzzy because of leakage but my valves specify a maximum leakage of 3 cc per hour, almost nothing. Even with much larger leakage, Casey is saying something with which I am not familiar.