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John McKee

Pressure Release Valves for Stills

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Lenny,

You must remove and replace that [60psi] PRV with a 15 psi (or less) crack valve. You are exceeding basic design criteria for pressure vessels which mandate a Professional Engineering Stamp applied to all vessels and dwgs for items that run above 15 psi....

...and 60 PSI is a bomb. Please replace immediately and prior to sale or don't sell.

I will advise anyone looking at this still to not purchase until adequate and proper safety devices are installed.

Cheers,

McKee

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McKee,

First, my name isn't "Lenny". But that is a small oversight in a response that is absolutely ridiculous by you.

I do not know who you are, but your "mission" to prevent the Silver Trails incident from happening is a noble one, if only you knew what you were talking about.

Seriously, stop.

Here comes some education for you buddy:

-A PE stamp is only required for DIV 2 vessels. This is a not a DIV 2 class vessel as it is not normally closed and is open through the distillation column. A reference for you to read about Class and DIV. Please read up before claiming to know anything about that particular topic: http://literature.rockwellautomation.com/idc/groups/literature/documents/wp/800-wp003_-en-p.pdf

-Run out of your house RIGHT NOW, because your copper pipes running through your entire home are....wait for it....90-120psi!! Yikes! That's a lot of bombs in your home. Even PVC pipe is rated up to over 150psi. So are your rubber tires in your vehicle, and on and on....you get it.

You are dangerous to this forum community. False and misleading information for the sake of you trying to look smart is no place for this forum or any for that matter. Do not try to come up with some other smart response to this. You are wrong. Anyone on this forum can do their own research based on the facts I just gave.

Give it a rest.

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As a professional engineer who sizes relief valves for chemical plants for a living I have to agree with John. Don't get mad at him because he gives you an answer you don't like. He's trying to save people's lives. I agree with him. What you have is very dangerous and the relief valve needs to switched out to one with a lower pressure. 15 psi max. It won't be expensive just do it.

I'm typing on an iPad so I won't go into much detail, but what you said above is incorrect. Yes the still is normally open to the atmosphere, but a full hazard analysis needs to be done for a system and you will find many modes of failure such as plugging.

Beyond that the design pressure needs to be calculated, which I'm sure wasn't done. The relief valve can't be set above that design pressure. It's very possible that a still could be built to only handle pressures below 15 psi. The reason people often use 15psi relief valves is because that the limit to which boiler/pressure vessel inspectors will inspect.

And generally pipes can withstand higher pressures because of their wall thickness relative to the cross sectional area.

John please don't give it a rest. I support every relief valve comment you make on this forum.

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Doc,

Thanks for the kind words, it can be hard to ask for simple safety. Bill Owens and the forum moderators are working with me and people like me to get a level of basic safety required for selling items across this forum, one of which is proving 15 psi PRV valves are installed on any system sold.

State-38, I apologize for not knowing your name and for using the Lenny I saw on a previous post, unfortunately I still don't know your name. But you are incorrect in every aspect.

A 15 psi PRV is less than $50. Just swap it out and sell something safe. There is no argument you can supply to the contrary and if needs be, I'll personally get your posting removed from this forum tomorrow if you can't supply a basic level of safety to what you're selling.

Cheers,

McKee

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One more thing I forgot to add. The set pressure is not the only variable. You also need to have the correct size relief valve. This is a much more involved calculation that looks at pressure drop across the orifice in the relief valve.

This is especially important for larger vessels, vessels with low design pressures and vessels with high heat input.

I can't say that any relief valve set at your design pressure will work, but it is much safer than one set too high and will reduce the energy release in the event of a tank rupture.

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While I respect anyone trying to give potentially lifesaving advice, I feel compelled to point out that henpecking a single piece of the puzzle is rarely a sound strategy.

To that end, I would point out two things:

First, a still - especially a pot still - is, as we know, not a "pressure vessel" during normal operation. Well-maintained and properly cared for, there's no risk of extreme pressures building inside the boiler.

To that end, and with respect to the Silver Trails incident - while pressure relief mechanisms are fine, it should also be pointed out that the first thing to not do would be to not pack the column with 20 lbs. of glass marbles, thereby creating a pressure vessel where one should not exist.

Context. It's super important, always.

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Old Spye,

Context is important, but one note....

In every industry, other than micro-distilling, distillation systems are always considered "pressure vessels", always (even those that run in atmospheric conditions)....and the design of both still and safety devices are driven by that starting point. Which means that PRVs are always sized and installed for correctly designed and constructed systems.

...and Doc, thanks for being more complete on the answer of PRV, not just set pressure but also total volumetric flow that the PRV would need to be able to release. I feel that someone in our community should be able to help State-38 size a correct PRV or get him to someone who can.

This is important everyone, more people are going to die if we don't start taking basic safety seriously. In the last year alone there have been 3-4 major micro-distillery incidents that have resulted in major life-long injury and/or death. This can't be argued away by examples of pressure in water pipes and tires. This is a careful and considerate plea to do things right. Please help lift the industry to a higher standard.

Cheers,

McKee

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Folks,

To say that I am incorrect is, well, incorrect.

Doc - It just so happens that I am an engineer as well. A petroleum and process engineer. Well respected globally in the oil and gas industry. You mention that my statement was incorrect. But you did not say what was incorrect? If you are going to call someone out, do so specifically and reference the facts so the rest of the people here can read and, most importantly, learn. A still (at least my stills) are NOT normally closed and therefor fall as DIV 1. A still is not "normally closed" because it has a big, open, copper pipe sticking out of it that keeps it close to atmospheric pressure during all times. If that still head were to clog, ie have glass or copper marbles shoved in it, then yes, I would agree you are testing the boundaries of a "normally closed" system which would fall to DIV 2 and would require a PE to examine with necessary PRV and other layers of protection in place. These are the facts. I referenced a link in the previous post if anyone, including yourself want to learn about CLASS and DIV ratings.

McKee - I will reiterate that I find the pursuit of safety noble, but your approach is aggressive and uncalled for. I am sure anyone reading this would agree that they cringe when they read how you force yourself into peoples post in an aggressive way. Two times now you have made threats on this topic. Threats are not welcome in these forums. Saying that you know Bill and then threatening to have a post removed because YOU feel you are correct is dangerous to this forum community that people can not post facts without the fear of being taken down because they counter to your statement.

The realities here people: A normal, well maintained still is a DIV 1 rating. PRV is NOT a legal requirement, nor is a PE examination/stamp needed on a DIV 1 vessel. THAT IS FACT. Now, if you feel that a PRV adds additional safety, and you want share your opinion on that with this forum, then do so. But do so with taste and not aggressively.

Opinions are nice, and of course welcome. Facts are facts.

Now that McKee has shat all over the original intent of my posting, I will say this to make the world right for all who have commented here.

DEAR POTENTIAL BUYER:

If you want a 15psi PRV on my stills, I will buy it, install it, test it for you. Safety is a very big concern for me.

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I'm not here to argue, and this probably belongs in another thread, but the link you referenced above pertains to electrical classification (which I also do as part of my job). It has nothing to do with relief valves.

API 520 & 521 should be followed for sizing a relief valve

ASME Section VIII should be used for all pressure vessels (above 15 psi)

Other codes can be used for determining pressure ratings for vessels less than 15 psi (API 650 or UL 142)

Without a design pressure a relief valve can not be accurately sized.

I am sorry this hijacked your thread, but it's an important issue that needs to be addressed and people do not take seriously enough in this industry.

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Doc - The link I provided has to do with CLASS and DIV ratings. Which was a direct reply to McKee and his statement about having a PE stamp.

You are making the claim, and so is McKee that a still is a "pressure vessel". You just wrote it in your last reply and McKee has referenced it in this thread as well. Let's talk facts here people. The implications you are making that a still is a "pressure vessel" can actually be quite dangerous to our industry in terms of permits, licensing, approvals, etc... More regulation in our industry? If you can provide a link to a document that states the specific legalities of a still being classified as a "pressure vessel" and therefor needing to be treated as such, I will happily admit that I am wrong and back down.

A still is NOT a "pressure vessel". If you are arguing that it is, then please start another thread and ponder that question as you mentioned in your last post. Seems to me that would be a great thread for McKee to start up and moderate that discussion.

Safety is of utmost importance. Facts are too. Telling people they have a BOMB, as was done by McKee in my case here is called fear mongering and goes too far, especially when the facts do not support it, which they do not in my case. This is damaging and the subsequent threats by McKee are called bullying.

As more people get into the industry, you are going to see more and more injuries take place. We work in an inherently dangerous environment. Use common sense to clean your equipment appropriately. Test relief valves regularly if you have them. Ensure your vessel is not going to pressurize of you don't have PRV's in place. All electrical devices, including heating elements and their controls should be sealed for intrinsic safety. Use this forum to educate these new people. Don't scare them away with your bullying and fear.

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A slight, semi-hijack. We have a 150 gallon pot on which we have a 5 psi pressure relief valve (and vacuum breaker) in the pot and 15psi PRV in the steam jacket. I can't fathom why you would want a 15psi RPV in the pot. We have never seem even the slightest needle quiver on our pressure gauge on the pot

If you get that high (15PSI) something has gone very, very wrong. What am I missing?

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EB,

You have it totally correct, if the pressure goes above 15 psi, something is very, very wrong....meaning a PRV of 15 psi crack (or less) will save you from a very bad incident.

Read the Fire Marshal Report for the Silver Trails Incident. The PRV was a 125 psi crack and something very, very wrong happened. If that still had been outfitted with a 15 psi (or less) PRV, it would probably be safe to say that the final outcome wouldn't be what did occur.

I'm glad to hear you also have vacuum relief. Spot on for having a safe system.

Cheers,

McKee

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Considering this was supposed to be a thread for my equipment and was completely hacked by McKee and his insistence to force/demand his way or, as he threatened: "I will have you removed from this post and recommend nobody buy your equipment", I will repost my ad and start another thread for it.

EB - Glad to hear you have the safety devices in place that you do. Never hurts to employ multiple layers of protection. Hijack away at this one. My original point to sell my equipment is toast and most definitely damaged by McKee and his false claims/statements.

McKee - Get your facts straight before you start flexing your opinions on other threads. I will be watching you to make sure you are not bullying. Good luck trying to get support from the distilling community to have a still regulated by the feds classified as a "pressure vessel". Checking out your website, you may in fact be building DIV 2 stills with your process as these appear to be normally closed columns. Does your local Butte, MT zoning manager know you have a potential DIV 2 process? Also, there is ZERO mention of pressure safety on your website. You know, the website that you sell distillation equipment for. http://www.headframestills.com/. ZERO mention. I find it ironic that you hijack other folks trying to sell equipment with your specific PRV demanded statements, yet do not yourself describe anywhere these topics on your own website. Heck, there is no mention of safety at all with your equipment. If I made stills, then took on a mission to strongly push PRV safety in these forums, I would sure as heck make sure I have those facts stated on my own website.

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EB,

You have it totally correct, if the pressure goes above 15 psi, something is very, very wrong....meaning a PRV of 15 psi crack (or less) will save you from a very bad incident.

Read the Fire Marshal Report for the Silver Trails Incident. The PRV was a 125 psi crack and something very, very wrong happened. If that still had been outfitted with a 15 psi (or less) PRV, it would probably be safe to say that the final outcome wouldn't be what did occur.

I'm glad to hear you also have vacuum relief. Spot on for having a safe system.

Cheers,

McKee

Yes. Something "very very wrong happened".

What happened was that some genius clogged the column. Intentionally.

As I said, I'm fine with PRVs. I think they're just super.

But I expect that we reasonably acknowledge the fact that anybody who is going to stuff a column full of glass marbles and create a +125psi pressure condition is probably going to find some way to blow himself up, PRV or otherwise.

In 30 years as a licensed pilot I've seen all kinds of people die from stupidity. In 20 years as an EMT I've seen all kinds of people die from stupidity. Frankly, if it weren't for stupidity we'd have a pretty serious overpopulation crisis in this world.

You're never going to be able to idiot-proof the world.

There's been some good dialog in this thread. But it's also been a little overbearing.

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I really really don't want to respond, but I can't help myself because this is a matter of safety. I absolutely hate forum arguments.

A relief valve is for emergencies. You are 100% correct in that a still is normally open and that it will not pressurize under normal circumstances. It is there for when something goes wrong such as clogging, plugging, pinching, fouling, etc. Yes the chances of this happening are very low, but the consequences are extreme. It's part of a SIL Study (Safety Integrity Level), which looks at risk matrices based on the probability and consequences.

I am not advocating that a still be classified as a pressure vessel. I'm saying that a relief valve should be used to prevent over-pressurization of a vessel and an un-controlled pressure release. The relief valve should be set at the design pressure of the vessel. Not having a design pressure makes it hard to determine a relief valve requirement, but at least one set at 15 psi will cause less damage if something goes wrong (again not saying that something will).

Also a DIV 2 classification has to do with flammable vapors and electrical equipment. Yes, the area around a relief valve which discharges ethanol vapors is a Class I, Div 2 area, but that has little to do with the relief valve set pressure or size. A non flammable vapor needs a relief valve just the same as a flammable one (google boiler explosions). Electrical classifications is a completely separate topic from this.

And if McKee can save one life for being intrusive it's totally worth it.

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Doc - DIV rating and Boiler safety are two separate topics. Agreed. It was in reference to the P.E. stamp comment.

A Process Hazard Analysis (PHA) can be done by each distillery for their equipment. A Hazard and Operability Study (HAZOP) can be done by each distillery. A Failure Mode and Effects Analysis. Layer of Protection Analysis (LOPA). And on, and on. These are specific for certain industries and are only expected when a certain threshold of hazardous/flammable/combustible material is present. So, with all due respect, I believe a SIL rating is not appropriate for boiler pressure, or "when something goes wrong such as clogging, plugging...." unless you are talking about the alcohol vapor release being the hazard, and more appropriate for the type of material you are working with, your fault tolerance, probability of failure and consequence of failure releasing that chemical into the environment. It sounds like you may deal with this type of stuff outside the distilling world, as do I, and I can assure you, I do not want the regulations associated with this for my distillery. Common sense and basic education should be the first line of defense.

To get back to my point. The point is....this was a forum post for selling equipment. There were false and damaging comments made by at least one individual to that end. As OldSpye pointed out, some people are just not smart in the world and they are going to do not smart things. If the intent is to educate people to avoid potential explosions, then it was not done correctly by McKee and was in fact aggressive with false statements. That is dangerous to a forum such as this. I fully support safety and those who go the extra mile for it. We do. But I will not sit idle as someone attacks me with bold print and threats. There is no place for that here. That is all.

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McKee - I will reiterate that I find the pursuit of safety noble, but your approach is aggressive and uncalled for.

I concur. Along with 800 years of international experience. The many do not need to suffer for the glaring mistakes of the few. Hang up your badge and gun for a while and give it a rest.

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Im curious, but I dont remember seeing a PRV on any of the german stills that are kicking around. A vacuum breaker yes, and PRV on the steam jacket yes.

Anyone out there own a Holstein or Carl who could correct me?

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State38Distilling

can I ask you a simple question?

What is the reason for putting a 60 psi safety device on a vessel that I assume has not been certified as a pressure vessel?

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I don't pretend to know the finer details of Standards for pressure vessels but I do understand the basic principals.

If a certified pressure vessel had a 60 psi relief valve on it I would be reasonably confident in saying that the vessel itself had been tested to at least 90 psi

agporte, am I in the ballpark here?

If I was buying some type of steam boiler and it had a 60 psi safety valve on it then I would initially assume that it was designed and manufactured to not rupture till well over 60 psi. (a pot still is a steam boiler)

It was mentioned on page 1 of this thread that a pressure safety device needs to release VOLUME as well as pressure.

eg a 5 psi 3/8 inch valve is totally useless if the still tries to puke solids through that.

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If anyone is confused like I was initially, about where the conversation for this thread started, look at "complete distillery for sale". The thread has been split off "For sale" into "Safety"

John McKee I don't think you over-reacted. If I had read that post before you I would have written a similar response. Safety is a very serious issue.

If someone put a 60 psi relief valve on a vessel they built when it should have been 15 psi maximum then I would be concerned about the safety of their entire build.

I saw a photo of a large boiler and a tall thin column with plates. eg New inexperienced owner could over-fill with thicker than normal fermented mash, the thing builds up pressure as it tries to puke solids up through the plates........kill the heat and get out fast.

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Here is the valve I used on my still:

http://www.glaciertanks.com/Pressure_Relief_Vacuum-Pressure_Relief_Valves_Vaccumm.html

If I had it to do over again I would probably use a pair of these (one on top of the column and one on top of the dome) and pipe the output to the exterior of the building.

http://www.amazon.com/Apollo-Valve-13-510-Bronze-Pressure/dp/B002KTZB4Y/ref=sr_1_2?ie=UTF8&qid=1443366429&sr=8-2&keywords=10+psi+steam+pressure+relief+valve

If I was giving input on a policy/practice it would be to install a 10PSI valve ahead of each potential choke point in your vapor path. So in my case that would be one on the dome before the potential choke point of the column and plates, and one on the top of to column before the potential choke point of the condenser/parrot.

To my thinking a 60 PSI valve seems inappropriate on any still..

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The problem is these guys are just grabbing a water heater/hydronic boiler pressure relief valve, the 60psi variants are low pressure relief for water heaters (which usually take 150psi). They are also completely the wrong PRV.

If you don't know the difference, you grab the PRV and think you are safe.

I also like the Apollo 5psi valve, but I've been trying to keep an eye on something sanitary that doesn't cost an absolute fortune. I'd like to be able to routinely disassemble the PRV and be able to inspect it and clean as necessary. I get worried that occasional foam-up in the boiler will cause caking/residue that the CIP can't reach to clean.

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