I’m not a propane guy, even though I dabble in it. Anyone build a flare torch? I have a 2800 gallon MC331 cargo tank I need to empty to hydro test it. Show me your righteous flares!
Can't you xfer pump it to another tank ?
For sure. There will still be some vapor retain left over that will need to be vented and burned off. I do see there is specific evacuation pumps available for small volumes.
Shop I used to work for and is now in the same parking lot as my shop. Has a couple of the big long flame flares. But they now use a 6 burner torch thing they got somewhere. Like a really big stove burner. Hide it behind a short pile of cinder blocks and nobody calls the fire department. It will take all day or more to burn off a bobtail. Make sure you get absolutely all the vapor first and maybe run a vapor compressor off the tank first until the belt starts to squeal so you don't have to burn as much. If you discharge the vapor you are compressing into the liquid space of the receiving tank, the receiving tank pressure should not rise so much.
If you need to hydro test it, why not just fill it with water? The gas will exit as you fill it. How many PSI pressure to test? Fill with water and test with pressure washer and you're done. Joe H
It still probably has 100 psi of vapor in it after emptying the liquid. Got to get that down to 0 psi before opening. Can't just let that gas rip, too much of it. Can't do anything with it until the tank is down to atmosphere.
I've been party to flaring the contents of a liquid butane pipeline that fed an industrial process. We used a rental flare. Here's a link to that sort of service. http://flares-stacks.com/combustion...es_portable_flare_systems_and_flare_ignitors/ Then another time, we ran 50 feet of hose to a 20 foot pipe that ended in a vertical section, surrounded by a coil of copper tubing with holes drilled in it. Controlled by a ball valve. The coil vaporized any liquid butane via radiant heat... No flame impingement on it.
Thanks everyone. I was guessing somewhere between 60psi and 100psi vapor pressure in the retain, depending upon the ambient temp. I’m either going to do the hydro myself or fly someone up from Seattle, if I can even find anybody willing to. I can get everything ready and have it filled with water. I’m only registered to do external visual and leakage tests with MC331. But, I can change that. Test pressure is 375 psi. I’ll have to get a nitrogen cylinder barged up. Next AML barge is in July. It was suggested to me that after I drain the water, to add 1 gallon of meth per 1000 gal capacity to dry up the residual water and vent. I found a shop in Seattle willing to walk me through a hydro. I might fly down.
Hmmm. Pressure washer, huh? I was thinking nitrogen. Have to think about that. Way easier to source a pressure washer vs nitrogen. Hmmm. I like the way you think, Joe—H.
Yet another thing I didn't know existed! Thanks for adding to the ol' knowledge bank gang!
The home made one sounds like a hot air balloon burner.
Just another thought ... The issue of a flare is ignition. Sometimes, a slug of liquid replaces the vapor, then the flame goes out. But if you have control of the release, no problem just reignite the flare. I had some fire training years ago with simulated propane tank leaks. Two teams of fire fighters with hose streams would approach the tank with a thundering pillar of flame. The second team covered the first with a fog nozzle as they approached the tank. The first team used their fog nozzle to blow the flame away from the tank to shut off the leak. The simulated leak was merely a tube connected to a propane truck tank, controlled by ball valve. 30 foot pillars of fire for a day only consumed about 30 gallons.
Anytime I want pressure like that I use an airless paint sprayer, better control than a pressure washer. At least simpler control as the pressure control, and drain are built into the unit already. If you use a pressure washer, you have to come up with more plumbing. How many gallons do you anticipate pumping between 100 and 375 PSI? a paint sprayer will be .25 to .5 GPM so instantly brings the pressure up in anything I've done, but I've never pressurized a 2,800 gallon propane tank. if we use 270 to 1 as the propane expansion ratio, then you have roughly 70 gallons of propane left in the tank at 100PSI? liquid vapor equivalent
Hmmm. Airless paint sprayer. That’s another good idea. The pressure up procedure is split into stages with hold times in between. Fine control would be nice. Calling around, nitrogen appears to be standard practice in the PNW. Appreciate the input. I’ll post pictures of this adventure. Holy-Moly. Now, LPG delivery hoses are in short supply. I found one in Seattle and they would prefer not to part with it. Need it for their own equipment. Supposed to be availability in July.
I'm curious if the nitrogen is just used to apply the pressure, or if there's a certain volume that provides a reserve of pressure? Must be a procedure, and I'd guess the pressure has to be cut off and the tank hold on it's own? Or maybe they use nitrogen because they're going to fill the tank with nitrogen as the water is emptied?
It’s inert and there is enough pressure and capacity to reach test pressure. Maybe a added safety benefit of diluting the residual vapor to way above flash point.
All depends on how full of water Coaldust can get the tank filled. It's mostly the vapor space that will absorb any flow. 100 % fill and likely a pint of water will produce 375 psi. Same principle as connecting skid steer attachment hoses... or not
If you fill the tank to the top so it's venting water out the top you don't need any volume, water doesn't compress. You want it completely full so if it does blow it just splits, not exploding like it would with a large air pocket. As to plumbing take one of the pressure washer nozzles and weld it into a fitting that will screw into the tank, hook wand to fitting and you're done. No plumbing, just one nozzle and fitting. The nozzle is just a larger air line fitting on most of the small washers. $5 maybe? Cheaper than whatever those AHs at AirGas want for a bottle of nitrogen. Joe H
Thank Joe—h If I park the rear axle on blocks to raise it up, I could probably achieve almost 100% fill. I like the pressure washer idea. I’ll need to determine the best place to make the connection. I could make a short whip between the handle and the fitting. Probably use a Cat/Parker style PD fitting. One of my Fairbanks customers has a flare they built in-house. I’m going to make a trip and check it out.
Just a thought ... Propane weighs less than water and only gets a 80% fill. Is there enough weight capacity of the truck to hold 2800 gal of water(23,500) plus the tank ? Or will you have to block the frame ?
And that’s a good thought. I’ve filled large ISO mods and DOT407 tank before with water. The ISO mod container chassis are certainly over weight and the tires do bulge. The 407’s are over weight, as well. The chassis do creak and groan. Lol. They don’t get moved after filling. I like to make sure the tires are not under inflated. I’ll ask that question. Thanks for the reply.
Yes that is a good thought hoss. A little bit of cribbing ahead of time saves a lot of grief. FYI propane only weighs 4.11 lb per gallon which is about half that of water!
They may creak and groan but I'm sure they don't get any more strain than when bouncing up a pothole driveway tilting from left to right, than full of water just sitting in a level parking lot.
BV ... Likely not more than bouncing in potholes. But consider .. 2800 gallons x 80% x 4.11 pounds = 9,200 pounds. vs 23,000 pounds of water at 100% fill. And the truck is only at 80% fill leaving the terminal, getting less at each stop.. Being the tank is being recertified, means some age and miles. I hate having to fix old broken stuff. Broken is bad... OLD, dirty, & broken is so much worse. I just replaced all the spring teeth on a hay tedder. When I went to the field, all the teeth were there. After a few acres, I noticed some missing. They looked good at first, but there were invisible cracks in the old teeth. Springs are good until they're not. Did I say I hate to work on springs ?
Emptying the water from ISO mods and DOT407 tankers within the Municipality of Anchorage is harder than it sounds. Municipal Water/Waste Water requires that I notify them before draining and they tell me how fast I can drain as not to overwhelm the sewer.
Ever get back to this project? Joe H
Hey Joe—h, Thanks for checking in. Sorry to leave you hanging. It’s on standby. I found a flaring torch at the fire department, I can use. And rigged up a hose, so I can use the pressure washer. At the moment, I’m on the eastern most side of the state performing a VK on another bobtail, under the midnight sun. This one still has the new truck smell. Beautiful Arrow build on a Peterbilt chassis.
Tourist season. No lodging available in town. I’m camping out at the tank farm between the RUG and the ULSD bulk tanks. Not so bad. No campfire.
Whatever happened with the methanol tank saga?
I get the diesel tanks .. But what's RUG ? Regular Unleaded Gasoline ? Hoping for fair weather for your camping. I've done the wet sleeping bag before
Not even dirty yet, and is that a rust streak already? Joe H
“Whatever happened with the methanol tank saga?” It’s all methed up. The last employee was terminated, recently. The pickups, tank trailers and tractors were transferred to the fuel division. I hear the terminal is for sale. Storage is hard to find, so I’m sure one of the local fuel outfits will purchase the property and demo the tank. Build new. It’s a great location with a barge landing and rail spur access. That disaster was over-shadowed by another tank farm tale of woe, further North. Same company. I’ll start a new thread about that. I think enough time has passed to protect the innocent. Ownership is being transferred at the end of June. They managed to burn down a brand new shop/warehouse complex and a entire tanker fleet. Destroyed a successful fuel and lube business in a five year time frame. Leaving nothing behind except bad memories and a oil stain on the tundra.
Made it home! Time to wash clothes, stock up consumables, invoice some jobs and hit the road again. Tank Tour Twenty-Two. Coming to your town or village. This time, the tank crew is headed up the Parks Highway. Willow, Trapper Creek, Cantwell, Fairbanks. V’s and K’s all the way.