Oxy Regulator Seat Assembly ?

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My regulator is working fine after rebuild kit install. No leaks dynamically or statically. My one question is, the seat assembly in the rebuild kit is solid brass, the one I took out has a hole drilled lengthwise from the bottom end of stem about half way up. there it meets another hole drilled in the side of the stem.There must have been a purpose for this extra machining, any ideas? (see bottom right pic, new & old seat assemblys)
Reply:I'll start out with the general comment that it's a very bad idea for the average person to do maintenance on O2 regs. Everything burns in the presence of 100% O2 under the right conditions. You won't even need an ignition source as simply the heat from the gas pressure is enough to often light things up. Any contaminants that get inside, even the oils from your hands or a small piece of lint can be enough to get the ball rolling.I've personally seen the results of at least 2 O2 regs that went BANG plus the one that burned when a glycerin filled LP gauge leaked. The good thing was the regs that went up were on a manifold system and not connected directly to the cylinders with the exception of the one that had the fire. I also was familiar with a person who was killed when an O2 cylinder she had just hooked up exploded. Theory is that oily dirt had gotten into the valve when the cyl was dropped in the dirt parking lot, but theres no way to prove it because there wasn't a valve left. I'm also aware of several others that had experiences similar to mine, but luckily were not at ground zero when it happened.The woman was killed only 6 days after I was seriously burned in a HP O2 "fire" when the O2 booster I was running went BOOM. Vaporized 20 plus inches of 316 SS 1/4" HP line and several SS heavy fittings. Circled are the remnants of the 1/4" SS schedule 80 (IIRC) T's and swageloc adapters. There's a good bit of tube missing that's not easily apparent from the way they hung the lines to take the picts. Again there wasn't enough left to determine the actual cause, but one strong theory was some contaminant like a bug or a spiderweb got into the system when the cylinder was changed out a few minutes before the explosion. It happened so fast I can't even remember the explosion. 3rd degree burns from my fingertips to my right elbow and a week in the burn ward. If I'm a bit touchy on this subject I think I have a good reason... This is a VERY bad place to try and save a few bucks. Send these sorts of things out to people who have the proper training and equipment/lubes to do O2 service.As far as the holes, it may just be a cost saving measure on the part of the manufacturer. I know I've seen small changes like this in reg parts before due to simplified parts manufacture. ( I'm a certified Scuba reg tech for 6 different companies and have been trained to do O2 service) I know in some cases things like this were done so that the reg could use some of the pressure to help "assist" opening and closing the HP seat. However IIRC the manufacturer decided that the additional machining didn't really gain them any significant performance advantage and they later chose to make a running change on the parts to save money..No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan
Reply:Thankyou for the concern, as it is these stories that made me very safety conscious. The only cleaning I did was with acetone on the rim where the diaphragm sits.When I opened the high pressure side my fingers where clean from the acetone. I replaced the 2 nylon pieces (bushing & washer) and put a tiny bit of Cristo-lube on the bushing and buttoned it back up.My question to you would be, how do I know the guy doing my regulator doesn't have a hangover or gets a call in the middle of doing my regulator?  Maybe I'm jaded but 57 years has made me aware that the only person you can trust with your life is yourself.  This Oxy stuff is not to be taken lightly, On that we agree.For the sake of conversation, maybe these tanks that have exploded have had lint or whatever floating around in the regulator for years and a fresh tank 2.2K lbs. and the perfect storm inside the regulator sets it off. Who's to say the contaminants didn't come from the factory or a professional rebuild.?
Reply:Acetone certainly wouldn't be among my 1st choices for O2 service except maybe as a precleaner. Chrisolube is an O2 compatible lubricant. I'll give you credit for using it vs something else.As far as how you know your service tech is capable and follows procedures, unfortunately you can't really tell. Only thing you can do is go with someone with a good reputation and history. On average with O2, if something is going to go wrong, it will happen usually the 1st few times it's gassed up if there was an issue with the service work. Most reputable places will pressure check the gear before they send it out. It will blow up on THEM, not you. Also should you be unlucky enough to have an issue, they have insurance to cover problems, not that it's much of a consolation if you are injured. Even though I know how to service regs for HP O2, I'd still probably send my own welding regs in to someone like OAdoctor here for service, Jim and I have had several conversions by Pm on some of the O2 damage we've both seen come in to the shop. I'm very picky about who services my scuba regs since my life depends on them in the type of diving I prefer doing. I can count on both hands the people besides myself I'd trust to do my regs. Most of them I dive with and all are reg techs I've personally worked with over the years, or whom I've known for a very long time. This is less of an O2 issue in these cases, as it is the fact when I'm over a mile back in a cave or at 240' the reg needs to work 100% of the time, no questions asked.As far as something just hanging around in the reg for years, I doubt that's generally going to happen. What I usually see is people who really don't take care of regs, whether they are for welding or whatever. I've seen plenty of guys swap out regs with greasy/oily hands and not even think twice about it. I'd bet 98%+ of these sorts of issues come from simply poor handling. However as soon as you open up the reg, you run the risk of getting things inside that shouldn't be there. The oil or grease on the wrench that just got used to open the cover for example, or something that got dripped on the "clean" rag that gets used to lay out the parts on. I've seen all sorts of non O2 compatible things used on regs and fittings, Buna Orings, pipe dope, silicone grease and all sorts of strange things. I'm often amazed more guys don't get seriously hurt handling O2. Probably the biggest reason is that most of these guys are doing stuff to the LP side and not the HP side of the system..No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan
Reply:The older Victor regulators had hollow stem.  Victor was the first company to use a design were the inlet pressure worked to keep the valve seat closed.   Before Victor's design, all regulators were designed to have the inlet pressure working to open the valve seat.  The hollowed seat assemble was to aid in closing the seat.  Victor  determined the extra machining was not needed  and eliminated it from all of the new seat assembles in order cut cost.  I have found that Victor's design, which is used by almost all regulators on the market today, is a lot better than the older design.  In fact, the original owner of Victor was injured by an oxygen regulator an set out to designed a safer regulator.   The SR in  Victor model numbers originally stood for Safety Regulator.  Of course they can not use that description today, because of liability.    We, with all manufacturers, recommend that only trained personnel service gas apparatus.  We do offer repair kit for those individuals that want to repair their own equipment.  However, we require a Liability Wavier Agreement to be accepted before an online order can be processed.    Our rebuild cost is usually only $20.00 to $30.00 more than the repair kits, and we replace the gauges and inlet connection on all most all of the regulators we rebuild.   Also, without the reaming tools, some  torches are not repairable in the field.  We ream the seats for cutting tips and valves on most torches we rebuild.  We are  here to help any one that wants to rebuild their own equipment or someone wanting equipment serviced by trained personnel.  Jim BillingsleyRegulator & Torch Exchange, Inc.OAdoctorwww.regulatortorchrepair.com
Reply:Thanks JimI thought it was something along those lines.