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Absinthe Pete

Boiler PSI Questions

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Ok so lately we've had some boiler questions and I working on hooking ours up now so I thought I'd ask the collective. I noticed people mention that they're using in the 5 PSI range from their steam boilers, what is the reason for that? Wouldn't a higher PSI heat things up faster? I have no clue as to the physics of it so sorry if this is a stupid question.

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Brian    6

Ok so lately we've had some boiler questions and I working on hooking ours up now so I thought I'd ask the collective. I noticed people mention that they're using in the 5 PSI range from their steam boilers, what is the reason for that? Wouldn't a higher PSI heat things up faster? I have no clue as to the physics of it so sorry if this is a stupid question.

I have three boilers and operate them so that they are all on only when I am condensing all the steam, like early morning start up or cooking and distilling. As things warm up they drop out one by one until the system reaches 15PSI. Recently changed out the standard Honeywell "Pressuretrol" with the wiz-bang L404F (15PSI type) which allows better control ranges for both main and differential. controls. These puppies will set you back about a hundred bucks. Since I now have a bigger still I need every BTU I can muster and these three controllers let me keep a max of ~15 PSI. They are set at very close pressure tiers like 15, 13, 12PSI. The other thing that happened was that the pressure relief valves overtime have sort of calcified and were releasing before 15 PSI was achieved which kind of scarred the poop out of my early guy....so new relief valves and the wonders of analog control. Those last couple PSI really make a BIG difference in the amount of heat you can throw at your mash....don't have the mass math handy but with about a 1,000,000 BTU's at hand every little bit helps. Insulation is a good thing to and I should probably practice what I preach. If you Google heat recovery you might find a system you could shove up your flue that would allow you to use some of that heat that couldn't possibly contribute to global warming or your gas bill....I assume you are using dirty steam and have a boiler recirculation system to replace used up steam with hot water condensate. Next time you are heading to the outhouse print yourself a copy of: http://www.bellgossett.com/literature/files/7250.pdf......or throw this pamphlet down on the bar the next time you want to impress the significant others...

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porter    0

Besides the excellent explaination above, you might also check on some other areas.

Insurance- some folks limit how much steam pressure you can hold for a particular policy level of insurance. Liability increases with the pressure, just not sure what PSI is considered dangerous. I know commercial, schools, etc. are this way. Don't use steam, so I never have dealt with that.

And are you talking about the 5psi a still cooker relief or on the steam line itself? 5psi seems a little low if on the steam line.

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Jedd Haas    4

Great info, guys! It happens that earlier today I heard about the insurance issue Porter mentions; I'm planning on LP steam, so no worries.

Brian, can you tell us more about the boilers you have and the approximate cost? I've been seeing numbers all over the place. Also, how big are your stills, and what pipe size did you run?

Is 1,000,000 BTU your total steam generation capacity? Or is that the amount of natural gas you're using at full boil on all units?

Did you install the flue heat exchanger you mention? If so, what do you use it for, preheating perhaps?

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MadMacaw    2

Low pressure boilers are 15 PSI. In most municipalities and states there are no special regulations for their use. Optimally you should set your delivery pressure to between 12 and 13 PSI with no less than a 3 PSI deadband. All of this is assuming you are using steam jackets, not steam injection which is another topic all together.

Eric Watson

AlBevCon

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bradocaster    0

I bought a used boiler that operates in the 5-7psi range hoping to use it on a steam jacketed vessel. is that not enough pressure?

Brad

Low pressure boilers are 15 PSI. In most municipalities and states there are no special regulations for their use. Optimally you should set your delivery pressure to between 12 and 13 PSI with no less than a 3 PSI deadband. All of this is assuming you are using steam jackets, not steam injection which is another topic all together.

Eric Watson

AlBevCon

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coop    1

Boiler size is directly related to amount of steam you require. If you want to run your still and mash kettle at the same time then you need to know what the manufacturers of those recommend. It is always better to have extra. Your equipment will only handle just so much steam safely. Use just what is recommended through your equipment. If you go above the 15# output of a boiler you will fall into another problem with local inanities (state and local inspectors). Coop

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Thanks for the info. I have a 220 gallon still with a capacity of 175 gallons, with a steam coil on the inside, so not jacketed. My boiler is rated to 100 PSI. I'll more than likely use 3/4" to hook up to my steam coil as it's 3/4" copper. The line coming out of the exit will either be 3/4" or 1/2" depending on the steam trap I get.

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Brian    6

Thanks for the info. I have a 220 gallon still with a capacity of 175 gallons, with a steam coil on the inside, so not jacketed. My boiler is rated to 100 PSI. I'll more than likely use 3/4" to hook up to my steam coil as it's 3/4" copper. The line coming out of the exit will either be 3/4" or 1/2" depending on the steam trap I get.

At 100 PSI you would most likely need a operators' permit or license and you might (would) be subjected to semi-annual boiler inspections and other parties might take an untoward interest. "hey bubba, lets get some x-rays of these welds and when was it again that you had your pipes tested?....can you please bring me that paper work??? Sure next week would be fine, but you can't operate until...hey, what's the ASME rating of this elbow?" Reading between the lines, it sounds like there might be some non-standard and NON-certified or certifiable bits in your system. Because you're boiler is rated at 100PSI doesn't mean you must operate at that pressure and it would truly scare me to run at 100PSI. REALLY SCARE ME!!!! If you take a look at the Hoffman Specialties site you can see the condensate return ratings for traps for a given operating pressure. If need be you can add another return if you think you are on the edge.....but please don't operate at 100....we need good absinthe in the world.

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LMAO,I have to say that this was the best laugh all day. Since I am reserching boilers for my project and getting frustrated it helped a whole damn lot. Thank Guys I needed that. Plus I truely lerned somethings.

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