Copper coax dehydrator orifice?

[spinjector]

Hi all,

We have a dehydrator on our 50kw AM that I'm pretty sure is shot and just blowing un-dried air.

Before smoke & flames happen, I'd like to slap on a nitrogen tank.

I was once told that somewhere at the end of the copper is an orifice, much like the orifice on a gas flame like the pilot light on a furnace.

Where would this typically be?

What would it look like?

How many would there be, and if two or more, wouldn't it be advisable to make sure one or more are not plugged?

Inside the transmitter building, its all 3" copper, and then going down out of the phasor is two runs of 3" Heliax, and one 1-5/8", but those are not connected to the 3" copper. So I'm assuming that any orifice that may exist is inside somewhere.

Thanks.

 

[DTV-Chief]

The tank of nitrogen would need a regulator to step down tank pressure to desired line pressure. Then, you would disconnect the tubing connecting your dehydrator to your coax system and hook up the output of the tank's regulator to that same point. Check your local hardware store for most common fittings. Regulators are available from broadcast suppliers or sometimes off eBay. Spray on or brush apply some soapy water to all fittings and connections and keep tightening until no bubbles appear.

 

[joep]

Hi all,

We have a dehydrator on our 50kw AM that I'm pretty sure is shot and just blowing un-dried air.

Before smoke & flames happen, I'd like to slap on a nitrogen tank.

Thanks.

Typically, you'll find a purge valve at the far end of each pressurized line. If you think that your dehydrator has been compromised for some time, then yes, I would recommend that you get yourself a nitrogen tank and purge each line.

I would elect to repair or get new desiccant for the dehydrator over refitting the system for nitrogen.... unless you're really into hefting those cylinders around. Most larger systems leak to some degree, and you'll get tired of that after a while.

 

[spinjector]

Well... I used to do the tank-lugging for another station I worked for; it wasn't too bad. The tank would go flat every couple of months, and it was a nice drive in the country for an afternoon.

I'm not sure we can afford to get the dehydrator refurbished at the moment. The last time I got a dehydrator refurbished, it cost $1,600, so I bet the brass & regs for N2 is a bit cheaper.

Now that I've said that, it makes me wonder if it wouldn't just be cheaper to buy a new one. I'll have to look into it.

 

[nmoore6676]

Hi all,

We have a dehydrator on our 50kw AM that I'm pretty sure is shot and just blowing un-dried air.

Before smoke & flames happen, I'd like to slap on a nitrogen tank.

Thanks.

Typically, you'll find a purge valve at the far end of each pressurized line. If you think that your dehydrator has been compromised for some time, then yes, I would recommend that you get yourself a nitrogen tank and purge each line.

I would elect to repair or get new desiccant for the dehydrator over refitting the system for nitrogen.... unless you're really into hefting those cylinders around. Most larger systems leak to some degree, and you'll get tired of that after a while.

Unless the line is pretty leaky tanks of gas should last for some time, I've used them for the waveguides at unattended cable TV CARS receiving sites. Telcos often strap them on poles to keep their cables dry and I don't see them replacing tanks that often.

However you should not be "lugging" the tanks around. Get a proper tank carrier dolly and also be sure to secure them when in place and any extras, even empties, capped and fastened with a chain while in storage. Those tanks have a lot of pressure and can become rockets if they fall and hit the top assembly the wrong way. The gas supplier should be able to steer you to or sell you the proper gear to handle and store them but you might like to shop prices. There are automatic switch over systems that change the supply tanks when one gets low but they are somewhat pricey and probably a waste if you can check on it once in a while.

 

[spinjector]

However you should not be "lugging" the tanks around. Get a proper tank carrier dolly and also be sure to secure them when in place and any extras, even empties, capped and fastened with a chain while in storage. Those tanks have a lot of pressure and can become rockets if they fall and hit the top assembly the wrong way.

Don't worry, my grandfather & uncle have owned a welding shop since before I was born. And my father is a professor of Industrial Safety and teaches the OSHA guys their game. So I know a bit more about tanks and safety than the average person.

I could probably build an automatic switchover system with parts from my aquarium. I'm an avid planted freshwater aquarium enthusiast, and I have a 5lb CO2 infusion system with an LP electric solenoid attached to a PH probe & timer to turn it on & off based on acidity & daylight.

An auto-switch system acually seems like a great idea. I could prolly slap something together for about $100, and hook it into the Burk to let me know when the primary tank goes flat and it switches to the backup.

All that would be needed a 2nd tank & HP regulator, one solenoid, a check valve, an LP pressure switch, and a t-fitting. I could prolly get everything except the solenoid in the welding & compressors section at Homogeneous Depot.

 

[nmoore6676]

However you should not be "lugging" the tanks around. Get a proper tank carrier dolly and also be sure to secure them when in place and any extras, even empties, capped and fastened with a chain while in storage. Those tanks have a lot of pressure and can become rockets if they fall and hit the top assembly the wrong way.

Don't worry, my grandfather & uncle have owned a welding shop since before I was born. And my father is a professor of Industrial Safety and teaches the OSHA guys their game. So I know a bit more about tanks and safety than the average person.

I could probably build an automatic switchover system with parts from my aquarium. I'm an avid planted freshwater aquarium enthusiast, and I have a 5lb CO2 infusion system with an LP electric solenoid attached to a PH probe & timer to turn it on & off based on acidity & daylight.

An auto-switch system acually seems like a great idea. I could prolly slap something together for about $100, and hook it into the Burk to let me know when the primary tank goes flat and it switches to the backup.

All that would be needed a 2nd tank & HP regulator, one solenoid, a check valve, an LP pressure switch, and a t-fitting. I could prolly get everything except the solenoid in the welding & compressors section at Homogeneous Depot.

I have worked with and around those tanks for years in different settings, welding set ups, laboratories using gas chromatography, and communications. In all of those places we were given strict instructions on handling the gas tanks (nitrogen, acetylene, oxygen, hydrogen, and helium). Never remove the top cap until the tank was secured was the #1 instruction. Number two was to never ever roll or drag them around, always use a dolly with a chain or strap holding the tank. So while you may have been around them you never got the instructions that I did.

Sometimes being too accustomed to being around things leads to a too casual attitude. My biggest dumb move was once when I tried to catch a soldering iron that popped out of the holder and rolled toward the floor. I was lucky it bounced off my hand so I only got a relatively minor burn, but it hurt enough to teach me to let it go if that ever happend again, a slightly melted floor tile is a lot less painful.

That top assembly and valve on the top of gas cylinders is brass and relatively soft, if it breaks the tank could shoot off like a rocket. Fortunately I never saw it but I was told that it could happen so better safe than sorry I always say. If it were a hydrogen or oxygen tank you definitely would not want a leak of any kind let alone a massive blow out.

Your suggestion on an auto switchover is probably doable and likely less costly than purchasing a ready made set up. I'd try it for sure, but I'm a tinkerer whereas some people aren't.

 

[spinjector]

I used to have many scars on my hands and legs from soldering accidents when I was a kid, but they're healed to near invisibility over the years. My father taught me to solder when I was about 6 years old, and I was constantly fiddling and soldering random wires and things to refine my skills. Numerous times I was soldering something over my lap and had a blob of solder fall onto my pants, melt through, and leave a nasty blister somewhere. Luckily it was always on top of my thighs, and not more sensitive areas. And then there were "the burns of learning" all over my hands, from accidentally touching hot irons & hot wires.

I'm sure those early days of having whisps of burning rosin and lead fumes curling up around my face got me some good doses of lead. I've often wondered if certain medical problems I have are related to childhood lead poisoning. I saw an article recently demonstrating a strong link between ADD and lead exposure. But I don't have AD.....Oh look!!! A squirrel!!! =-)

As for the step-by-step gas tank safety, it's all kind of "duh" to me. Somewhere long ago I saw the safety steps in a brochure or something in some of my father's teaching materials, and at the time I was like, "You really have to teach this to people? This is like common sense stuff."

I was once standing right next to a "tank rocket" accident that almost happened. It was when I was 17 and had one of my first jobs working at a local wedding/banquet/conference/buffet/restaurant type of place. The CO2 tanks for the soda system were all in an area of the kitchen near high traffic, and were NOT secure. I always eyed them warily, and once even mentioned it to my dad. I wanted to tell the owner about it, but he was a well-known jerk, and he prolly would have given me crap about it for speaking up.

Well this one stupid waitress chick was hyped up about something and running through the kitchen one day, and she dashed around the corner by the CO2 tanks, and slipped in a puddle of mop water - right at the end of the offending mop, and I was the one holding the handle. She stumbled and almost fell, crashed into the CO2 tanks, and knocked one of them over onto the terracotta tile floor.

I will NEVER EVER forget the deafening BONGGGGGGGG noise that tank made as it hit the floor. As I saw it start to fall and realized there was nothing I could do to catch it, my brain kicked into slow-motion-fast-forward-to-heck-with-the-fight-its-time-for-the-flight mode and I did three things as fast as the electrons in my brain could move: 1) I thought I was going to die, 2) I plugged my ears with my fingers, and 3) I turned and started to run the other way as fast as I could.

Well... The tank didn't go boom, and after everyone in the kitchen got over their shock from the noise and yelling at the girl for being stupid and running through the kitchen, I picked up the tank and put it back. BUT I don't think anyone there had any idea of the terrible disaster they just barely missed.

What no one realized was that the valve on the tank missed hitting the lower cross-member between the legs of the stainless-steel commercial kitchen prep table across the aisle. And it missed it by TWO INCHES. If the valve had hit that steel pipe, I have no doubt it would have been knocked right off. And what's worse, the bottom of that tank ended up pointing directly at the kitchen wall, which was nothing but 2x4 & drywall, and on the other side of that wall was a dining room crowded with a wedding party. If that tank had gone off through that wall, it would have been very, very ugly.

 

[boiseengineer]

The standard regulator you get on a Nitrogen tank will let a lot more than 4 psi through when the tank pressure gets low. We added a second low pressure regulator. One of those propane regulators used on stoves. You can crank them up to 4 psi. Get all the adaptors from the nitrogen supplier.

 

[spinjector]

Ah yes, I forgot the LPR... I would have remembered eventually, and been like "oh wait this will blow up the feed line at 150 psi"... =-)

 

[nmoore6676]

I used to have many scars on my hands and legs from soldering accidents when I was a kid, but they're healed to near invisibility over the years. My father taught me to solder when I was about 6 years old, and I was constantly fiddling and soldering random wires and things to refine my skills. Numerous times I was soldering something over my lap and had a blob of solder fall onto my pants, melt through, and leave a nasty blister somewhere. Luckily it was always on top of my thighs, and not more sensitive areas. And then there were "the burns of learning" all over my hands, from accidentally touching hot irons & hot wires.

I'm sure those early days of having whisps of burning rosin and lead fumes curling up around my face got me some good doses of lead. I've often wondered if certain medical problems I have are related to childhood lead poisoning. I saw an article recently demonstrating a strong link between ADD and lead exposure. But I don't have AD.....Oh look!!! A squirrel!!! =-)
A yes those days of of the smell of hot soldering irons the aroma of the rosin core. Practically every piece of electronic gear I owned back then were Heath Kits or EICO. I had an EICO oscilloscope and Vacuum Tube Voltmeter, wish I still had them but I sold them years ago when I left Ohio for California.

I also did my fair amount of copper pipe sweating the joints. My dad was taught in the Navy so every joint had to be perfect, smooth and no beads of solder sticking on them. Of course I was the dedicated one to crawl under the house where he had gotten a little too big to fit. I still made everyone of those joints to his specs.

Bucks Braun on his WBZI show last week was talking about how everyone panics if a thermometer breaks but like me we used to play with mercury as kids, rolling around the beads and watching them form bigger globs. I used to coat pennies to make them look like dimes.

Well spin I don't know how old you are but if you can go by me you are good to go for at least 67 despite the exposure we've had.

Oh yeah we probably had a lot of asbestos too, they used to wrap wires for high temperature locations with it, and it was in most toasters and their power cords.