HP Seats

[Jonny Wishbone]

Brilig,,,I buy my O rings online from the O ring store. You can buy an assorted kit or just buy the ones you need in whatever material you need. I have a 19 cf alum pony tank. Its ok in size and all but Im going to be switching over to a steel 15 cf pony tank from DGX. The alum 19 runs $130 and the steel 15 runs $220 if comes down to budget the alum will be just fine. For an older regulator for a pony tank I would probably go with a Dacor 360 due to its small size and ease of working on it. I say this because you already have a Dacor reg and I like keeping with all the same gear,,not to mention Im partial to Dacor regs anyway. The 360 is a balanced Diaphragm which is a bit more forgiving than a piston reg when not actually used much. As far as the second stage for the pony I would just get an inexpensive one on the small side. It doesnt have to be a Dacor. I would get one with a user adjustable knob so you can turn it all the way in when not in use so it wont free flow and you can crank it open for easy breathing when you use it. There are several small user adjustable regs by Oceanic that would work great. Get a used one on _bay just so you can go through it and tinker with it. Just my 2 cents...Tom

 

[Brilig]

Brilig,,,I buy my O rings online from the O ring store. You can buy an assorted kit or just buy the ones you need in whatever material you need. I have a 19 cf alum pony tank. Its ok in size and all but Im going to be switching over to a steel 15 cf pony tank from DGX. The alum 19 runs $130 and the steel 15 runs $220 if comes down to budget the alum will be just fine. For an older regulator for a pony tank I would probably go with a Dacor 360 due to its small size and ease of working on it. I say this because you already have a Dacor reg and I like keeping with all the same gear,,not to mention Im partial to Dacor regs anyway. The 360 is a balanced Diaphragm which is a bit more forgiving than a piston reg when not actually used much. As far as the second stage for the pony I would just get an inexpensive one on the small side. It doesnt have to be a Dacor. I would get one with a user adjustable knob so you can turn it all the way in when not in use so it wont free flow and you can crank it open for easy breathing when you use it. There are several small user adjustable regs by Oceanic that would work great. Get a used one on _bay just so you can go through it and tinker with it. Just my 2 cents...Tom

Tom, I went on ebay and found a Dacor 360 listed as in great condition for $15.00 so I couldn't resist. It just arrived yesterday and from the outside it looks great. I decided to put it right on to a tank and see what I had. It arrived without plugs in any of the ports so I figured I would swap over some hoses from my 1985 Dacor 950. The HP port threads are the same on both regulators but the low pressure ports on the 360 are a larger diameter than the HP thread and MUCH larger than the low pressure threads on the 950. Do thread sizes jump around or has there been a historical progression of standard thread sizes? Are hoses available in different size threads or will I need to manufacture some adapters?
Thanks, Mark

 

[rsingler]

Dacor had proprietary LP hoses for supposedly higher flow. If you really want to stay with that reg, I have a few old Dacor serviceable hoses in my home shop.

 

[herman]

They were not proprietary but were different ,1/2-20 which is another standard size although an uncommon one. A number of manufactures used the larger size as a sales gimmick for "more flow" which was BS but some bought it. I have a couple of USD regs that have that size. The best option is to use an adapter from 1/2 male to 3/8 female so you can use common hoses but Trident has replacement hoses (or at least the 2012 catalog has them). Hose Adapter 1/2-20 male to 3/8-24 female

 

[Jonny Wishbone]

Brilig, yes you will need the adapters. DGX or Leisure Pro has them in the 5-6 dollar range or like herman said, you can get hoses with a 1/2" end. I just use the adapters with braided hoses. I would open up the 360 and go through it. Give it a good cleaning/inspection and re-lube/reassemble. As long as the IP is solid and steady at 140 psi max, you are good to go. I don't know your level of ability to work on the reg so forgive me if I'm off base here. If you need some help with it I can walk you through it if you'd like..

 

[Brilig]

Brilig, yes you will need the adapters. DGX or Leisure Pro has them in the 5-6 dollar range or like herman said, you can get hoses with a 1/2" end. I just use the adapters with braided hoses. I would open up the 360 and go through it. Give it a good cleaning/inspection and re-lube/reassemble. As long as the IP is solid and steady at 140 psi max, you are good to go. I don't know your level of ability to work on the reg so forgive me if I'm off base here. If you need some help with it I can walk you through it if you'd like..

Jonny Wishbone, thanks to you, rsingler, and herman for the helpful information and links. I just got to opening up the reg today and it looks like it hardly had any use over it's lifetime. This reg is far simpler than my 950. It only has one O ring in that piece with the white nylon sleeve that the tail end of the HP seat slides into. I forget the name of that part. The brass washer that holds that O ring and nylon sleeve in place appears to be held captive by the edge of the main piece being peened over. The tail end of the HP seat slides in to it nice and snug with none of the plating worn off the HP seat. I'll just clean and lube it as is because it doesn't come apart. (if it ain't busted don't fix it). The rubber on the HP seat looks great. It doesn't even have a groove in it where it rests against the conical seat so I'll try reusing it. The diaphragm crumbled to pieces when I took it out. I will be ordering a sheet of that stuff you provided a link to in a previous post. The link you posted is for material that is 1/16 thick and that's just right for this Dacor 360 but I have a question. The diaphragm in my Dacor 950 is like twice that thick. Could I use the 1/16 material in my 950? Also, another question. When you say to set the pressure at 140 psi max, is there an ideal pressure I should be going for? I've also read about pressure creep. Does a new HP seat need time to settle in and form a groove before final adjustment? I think my ability to work on these things is pretty good. I used to be a prototype machinist so I really enjoy working on them. Any suggestions or advice is more than welcome.
Thanks again to everyone for all the help.

 

[Jonny Wishbone]

Yes,, you can use the new thinner material for your diaphragm in you 950 too. Because the new material will be thinner you will just turn in the big spring adjuster cap a littler more when adjusting IP. Dacor regs call for a window of 138 to 142 psi for IP so the rule of thumb is to just hit the middle at 140. If IP gets to high the reg will leak or free flow and will almost be impossible to tune. If you put it back together and the IP creeps there is a few things you can do before replacing the HP seat. You can disassemble and turn the seat 1/4 turn so it makes contact to the cone a bit different and do this til it finds itself at home with no creep. You can also take the seat and a pc of 600 or 800 grit wet paper. Wet the paper and put a drop of dish soap on the paper and lightly work the seat face in a figure 8 on your flat kitchen counter. Turn the seat in your fingers a bit after each few passes to get even results.This will refresh the seat surface back to being nice and flat. It is sorta like having your rotors turned on your car when redoing brakes. It trues it up. Make sure you have no nicks or pits in the edge of the cone that contacts the seat or you will have creep. The material used on the face of Dacor seats seems to be very hard and usually will only show a print or ring from the seat but I have had a few with a very slight grove. Grove or no grove they still work fine. It's all about the seat mating with the cone just right. Once you have steady IP leave the reg hooked up for a while and check it every few minutes. Purge the reg a few times here and there to make sure it keeps locking up at 140. There are pre 1991 360's and post 1991 360's. The difference is the post 1991 has a removable cone/volcano orfice. The pre 1991 the cone is built in and part of the HP assembly. They only redesigned this so if the edge of the cone was bad you can just replace the cone. On the pre 1991 you would have to replace the entire HP housing unit if the cone was bad. Make sure you lube the tail end of the HP seat a bit where it goes into the balance chamber. These could also be a reason a reg would creep but I have never had a bad one. As long as the o ring inside it is clean smooth and has a good fit on the tail of the HP seat it will be fine. Hope this helps and keep me posted on your progress.....Tom

 

[Brilig]

Tom, The balance chamber...now I remember. You have dated my reg to pre-1991 but no worries, it's all bright and shiny in there. I notice that the material in the McMaster-Carr link is for making high pressure pipe flange gaskets. I work in construction so when I get to the job site Monday I will talk with the pipe fitters and see if I can score a flange gasket of the same material and save some money. If it's possible to buy a flange gasket sufficiently wide enough to make into diaphragms (1-3/8 for the 360 reg) I will put up that information on the site here. What's the best lube to use? I have some silicone grease on hand that is marketed for use in plumbing fixtures so I figure it's non-toxic. I understand that you just put a small amount on and wipe away any residual leaving just a light sheen.
Mark

 

[Jonny Wishbone]

You must use a lube designed for breathing air applications. If you use or will be using Nitrox you must use an Oxygen compatible breathing air lube. I just use Tribolube 71 on all my regs which is Oxygen compatible for Nitrox. You can get it in a tiny squeeze pack for like 7 or 8 bucks. If you pm me your address i will send you a pc of the EPDM sheet for your diaphrams. I have more than enough for several years.

 

[herman]

Dow 111 was the standard for many years and all I use now. It does NOT have to be some special O2 rated lube as long as you are not going over 40% O2. Dow 111 is fine for 32-36 nitrox.