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Posted

We have a trade inspector asking a lot of questions about our still, which was custom built (160 gallons, stainless, tri clamp connections, direct electric immersion). They are asking lots of questions about whether it is listed, rated, and all that kind of stuff (sorry for the lack of specifics- I'm supposed to get more of their questions today and will repost). 

At any rate, what did you all do with your custom or personally built stills when these types of questions came up? This is literally the last thing standing in our way to begin operations, so my blood pressure is a little high. Any help or recommendation on how to address these types of inquiries will be immensely helpful. 

 

Thanks!

Posted

Tell them that the still is an open system and therefore not a pressure vessel of any sort and therefore the still itself does not need an ASME stamp or listing.  However, you really should have the proper pressure relief valve on the still as well as a vacuum relief valve.  If you went to your local hardware store and purchased a pressure relief valve for a water heater, then you need to remove it and take it back because it is definitely not the correct one for your 160 gallon still.  You need a 5 psi pressure relief valve for steam that will discharge at least 200lbs of steam per hr.  The pressure relief valve should be on top of the still boiler or on the line arm above the column and it should be plumbed to the outside of your building.  The vacuum relief valve should have a bore size of at least 3/4" 

The electrical system is a different story.  If the complete electrical system is not UL listed, then all of the individual electrical system components will need to be UL listed.  Also the control panel will need to have the voltage, phase and amp draw listed on it.  The cheap CE listed Chinese panels and CE listed Chinese parts will not pass most inspections here in the US.  CE is for Europe and parts of Asia and is not good for the US.  Your heating elements will certainly need to be UL listed.  The US made ones like Camco and Chromalox always are and the Chinese ones typically are not.  Here is something else.  Your electrical system should be rated at least NEMA4X which means that the everything is liquid and vapor tight.

 

Always remember safety first.

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Posted

Thanks for the advice. Glad to hear our pressure relief system is the right one (we didn't buy it from the hardware store - it was manufactured and sized specifically for our still). For the electrical, all parts are UL listed, so we should be good there, although I need to look into the NEMA4X rating, so thanks for the tip.

 

In terms of class and division, any advice there? I believe the still itself is class I division 2 (requiring 7 ft of clearance) and the 3 ft area around the parrot is class I division 1. Does that seem right?

Posted

Good job on the valves and electrical.

 

As I understand it, you are correct about the terms of class and division, including the distances, but sometimes inspectors have different ideas.  It is best to fallow the codes and don't volunteer any info about class or division etc. unless it appears the inspector is going above and beyond what you understand the rules to be and of course keep in mind that the inspector is God in this situation,  Be business like and pleasant, don't get stressed and don't ever, get angry or emotional with them.  i know these are common sense things, but I know someone who allowed their emotions get the best of them in a stressful situation and they regretted it later.

Posted

Still is class 1 div 2, without enough ventilation you need 25 ft 3 ft high classified and 5 ft radius of the outputs classified.   You can get away from this by having enough ventilation to keep your output diluted to 1/4 of the lowere explosive limit. Then no classification required.   Dalkita can help on the calculations. 

Posted

Ok, so most of the inspectors questions have been answered, but we have seven issues we need to resolve before we can open. Most have to do with how the still will have any effect on the HVAC system, if any. The fire Marshall has already said we are compliant, so this is the last person w need to satisfy to get the doors open.

We do have an engineer on board to help with this, but I am trying to get this done as quickly as we can. Does anyone have a reference for NEC classification of ethanol at 85 percent concentration? In addition, we are looking for checmical properties - vapor pressure, vapor density,  evaporation rate at room temp (approx 22C), etc. Any help there would be much appreciated. Most of the stuff I'm finding isn't consistent. 

Additionally, has anyone had to calculate heat byproduct produced by your still? If so, any suggestions on how to do that?

thanks again!

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