Ex Requirements

[richard1]

I am off in a tail spin with regards to CORRECT requrements and what people are doing with respect to Ex requirements.

 

The area around parrot and manhole is is Cl 1 / Div 1 and other areas immediate to still are Cl 1 Div 2.

 

So here comes the question...... What are people doing about the following instrumentation requirements on the still or immediate to it, because to do EVERYTHING in Cl 1 / Div 1 or 2 is unbeleiveably expensive

   Enclosure (panel)

  Switches, plugs etc.

   Lights on panel

   Level switches

    Temperature transmitters

    Pressure transmitters

 

 

I understand the comment ... well what's the value or cost of life BUT nothing that I see supplied by all suppliers is either Cl 1 Div 1 or 2

 

 

[Silk City Distillers]

Subject to interpretation, and there is little consistency across jurisdictions.  Even your initial premise is an interpretation that might not be shared:

Quote

The area around parrot and manhole is is Cl 1 / Div 1 and other areas immediate to still are Cl 1 Div 2.

 

[richard1]

On ‎12‎/‎11‎/‎2018 at 11:11 PM, Silk City Distillers said:

Subject to interpretation, and there is little consistency across jurisdictions.  Even your initial premise is an interpretation that might not be shared:

 

I agree.

 

But the big issue is what are the various suppliers supplying and here there is silence.  Maybe because it's a can of worms that they don't want opened.

 

I am all for doing the right thing but if they are not doing it, well then what to use or what is acceptable.  For example, a NEMA rated panel does not mean Ex rated.  Ex involves extra sealing, closure mechanism etc.   The same goes for other instrumentation on the still e.g. level switches, pressure transmitters and temperature transmitters.  Agitators is / are the apparent exception where the standard has the required rating for the motor.

 

The control panel I would prefer to mount on the still but my gut feel safety, is saying +6m away.

 

Just my thoughts on the issue.

[Skaalvenn]

I don't understand why one would want or need a panel attached to, or immediately next to the still. I had mine mounted about 30' away and it's not a hassle to use.

[richard1]

My primary panel is intended as a minimum +6m (~20 feet) away from the still and potentially more.  In this case I will still need a small intermediate panel on the still for connection of all connecting instrumentation.  In addition, I will have another small enclosure for the HMI.

 

The distance is more important for the cable to the heating elements from the 3 phase, 4-20mA SSR within the primary panel.  Here I am concerned about its heat within the panel as the SSR is quite a brute in size and am not able to install external heat sinks.  So some cooling potentially needs to be considered.

[Southernhighlander]

On 12/11/2018 at 9:05 AM, richard1 said:

I am off in a tail spin with regards to CORRECT requrements and what people are doing with respect to Ex requirements.

 

The area around parrot and manhole is is Cl 1 / Div 1 and other areas immediate to still are Cl 1 Div 2.

 

So here comes the question...... What are people doing about the following instrumentation requirements on the still or immediate to it, because to do EVERYTHING in Cl 1 / Div 1 or 2 is unbeleiveably expensive

   Enclosure (panel)

  Switches, plugs etc.

   Lights on panel

   Level switches

    Temperature transmitters

    Pressure transmitters

 

 

I understand the comment ... well what's the value or cost of life BUT nothing that I see supplied by all suppliers is either Cl 1 Div 1 or 2

 

 

Our PID electric heating systems meet all C1 D2 requirements in the US.  Our steam stills meet all C1 D1 requirements in the US.  C1D2 is much less expensive than C1D1 because NEMA 4 enclosure can be used for none arcing electrical components.   My business emerald gold sells laboratory equipment and we build it to meet C!D2 and C1D1 requirements.

Also we will be offering complete computer automation as an option for our Baine marie electric stills within the next couple of weeks.  These systems meet all C1D2 and C1D1 requirements and are are UL listed and certified.  Our new agitator motors are UL listed US made Baldor listed for C1D1.  Of course we will still be selling our PID electric heating systems.

Everywhere I look I see CE listed Chinese and European made agitator motors on stills and other distilling equipment.  Usually the inspectors let them pass but not allways.

Even with all of the above we still have the best prices in the industry apples to apples.

 

Thank you.

[Southernhighlander]

 

On 12/11/2018 at 3:11 PM, Silk City Distillers said:

Subject to interpretation, and there is little consistency across jurisdictions.  Even your initial premise is an interpretation that might not be shared:

 

  The safety codes are actually pretty strait forward.  My experience tells me that 99.333% of the time, my interpretation of the code gets my equipment through all of the customers required inspections the first time.  Even though it is not 100% that is a pretty good consensus.  Don't you think?  Also keep in mind that only .667% (around 1 in every 150) of ourstills  has failed the first inspection.    None have failed their 2nd electrical and or safety inspections.

[richard1]

8 hours ago, Southernhighlander said:

The safety codes are actually pretty strait forward.  My experience tells me that 99.333% of the time, my interpretation of the code gets my equipment through all of the customers required inspections the first time.  Even though it is not 100% that is a pretty good consensus.  Don't you think?  Also keep in mind that only .667% (around 1 in every 150) of ourstills  has failed the first inspection.    None have failed their 2nd electrical and or safety inspections.

Brilliant that's really well done and thanks for responding.

 

But you may or may not want to answer the following.  Of your total electrical / instrumentation supply the only item that has an actual Ex rating ..... is your agitator.  The rest have Nema ratings and or have good practice supply selection etc. or how ever you may wish to put it.

 

I in my build am trying to do as much right as possible without going absolutely overboard in equipment selection.  For example, level switch .... I am using the Endress & Hauser FTL31.  Pressure transmitter and temperature transmitter ..... All are closed, have good sealing with M12 connections or proper sealing glands and further,  none are EX rated.

 

This is my dilemma.  Am I asking for trouble.

[Silk City Distillers]

@richard1 - You would need a different sensor and an approach to intrinsic isolation.

If you want to stick with Endress, see part number FMI21 and the associated application note for how to use an intrinsic isolation unit in your controller.  I don't know the ATEX to US conversions, this may only get you to C1D2.  Either way, the approach is similar.  Compliant on the sensing end, intrinsic barrier (if necessary) on the controller end - this keeps your controller out of compliance scope (however distance may still be required).

https://www.e-direct.endress.com/us/en/two-rod-capacitive-probe-liquicap-t-fmi21-for-level-measurement-in-liquids

If you only need a point switch, you can probably go through the other sensors to find one that's appropriate.  I don't really see a way to make FTL31 compliant.

[Silk City Distillers]

Keep in mind switches can be challenging to make XP - as the switch really can't switch any appreciable current, or require enough energy to operate that the power supply poses an issue.  Instead, the switch can only switch a tiny sensing current, likely through a barrier, and the switching actually be done through a relay at the panel side.

https://en.wikipedia.org/wiki/Intrinsic_safety

Utilizing intrinsically safe techniques can often make compliance much easier.

[starcat]

It sounds like you want to put things together well, but your vision may be a bit rigid. Have you ever worked with Warrick Style controls? While you say you need a " panel " between your still and your main panel, all I needed were NEMA 7 junction boxes.

https://www.gemssensors.com/level/warrick/conductivity-based-liquid-level-control/intrinsafe

Our Experience.

Within a certain perimeter distance to the Still, we needed NEMA-7 protocols.

Beyond that zone we could go to NEMA-4 if its done carefully. The design Architect specified no open contact controls in this particular panel which is about 13 Ft. from the edge of the pot. This one is all SSR with EXP switches and just terminals inside.We put some other control panels fully outside the still room along with Deph control valves and the agiitator starter etc.

Outside the room we exit with Explosion Proof Conduits and can then do anything. The fact that you are going electric heat complicates matters. I assume you mean SCR control on your elements. I would think this is a major complication compared to steam fired with line voltage " right at the still." I would do the SCR control in a cooled cabinet if possible. The suggestion again is out of the still room proper. Your setup sounds challenging, and expensive but not impossible. Things like RTDs technically are not even capable of becoming a hazard. I have a white paper to this fact. As stated it is a lot about what your local inspectors want and your best efforts and research combined. Our instllation required 100% outside air and matching CFM of exhaust, so there is constant air change in the still room. We have also added additional interlocks to stop the steam flow to the still in the event of a number of related support utilities failing. Examples are:

The Exhaust Fan starts the Makeup air system and if it faults the MAU will go off line. If the MAU goes off line steam goes off line.

Steam is interlocked with MAU Main Fan, Chiller Loop pump, Glycol Return Temp. An open contact on any of these systems will drop out steam and trigger an alarm strobe.

There is also a required ethanol sensor in the room which  if triggered will drop out steam and light the alarm strobe.

[Southernhighlander]

16 hours ago, richard1 said:

 

 

But you may or may not want to answer the following.  Of your total electrical / instrumentation supply the only item that has an actual Ex rating ..... is your agitator.  The rest have Nema ratings and or have good practice supply selection etc. or how ever you may wish to put it.

 

I in my build am trying to do as much right as possible without going absolutely overboard in equipment selection.  For example, level switch .... I am using the Endress & Hauser FTL31.  Pressure transmitter and temperature transmitter ..... All are closed, have good sealing with M12 connections or proper sealing glands and further,  none are EX rated.

 

This is my dilemma.  Am I asking for trouble.

Richard 1 said.  "But you may or may not want to answer the following.  Of your total electrical / instrumentation supply the only item that has an actual Ex rating ..... is your agitator."

  Why would I not want to answer?  My passion is my equipment and there is no question about it that I am not more than willing to answer. To answer your question: No of course not.  We supply electrical components that meet whatever requirements that the customer has.  

We do our best to sell standardized systems that meet the correct interpretations of safety codes here in the US.    If the customer's requirement is that all electrical components meet the class 1 div 1 requirements, that is no problem for us.

So my agitator motors are good for class 1 div 1.  On all of my steam fired stills the agitator motor is the only electrical component on the still.  Dephlegmator and final condenser cooling is automated by a thermostatic valve which is inherently explosion proof.  Some of my more advanced multi bubble plate column steam stills utilize pneumatic, grounded, ethanol pumps which are inherently explosion proof.  The distribution pumps from the spirit safes are ex proof as are all of our other equipment such as fermenters and mash tuns et.  All of our float switches are explosion proof, etc etc.

For my pro series electric baine marie stills the agitators are good for c1d1 (NEMA7). Sometimes the safety inspectors say that the area around the manway is c1d1 so the agitator motor must be rated for C1D1.  There may also be a C1d1 around certain types of parrots, but it is a small area and I have no electrical components in that area..  We have electric immersion heater enclosures and a junction box enclosures down at the bottom sides of the still pot outside any c1d1 hazardous environments, but inside the c1d2 environment.  Non arcing electrical components in C1D2 areas must be in NEMA4 (dust proof/liquid proof enclosures).   They are not required to be NEMA 7 which is explosion proof. Only 1 out of almost 300 of our stills had a state inspector say that the area around the bottom of the still pot was class 1 div 1 instead of class 1 div 2.  However that still should pass it's next inspection no problem.  Our control panel is in a NEMA4 enclosure but is outside the class 1 div 2 area which is generally just 6 or 7ft from the still.   

A distilling area where there are no hazardous vapors under normal operating conditions should be classified C1D2 within in a designated distance from the still  Areas that have explosive vapors present under normal operation should be classified C1D1. That is very easy and straightforward.  

To further answer your first question.  We have FIP pumps, double diaphragm pumps, centrifugal pumps etc that are good for C1D1 and C1D2.  All of our steam stills are good for C1D1 and we can build any electric baine marie still to C1D1 if the customer so desires.

My other business has been selling laboratory stills as well as commercial and industrial vacuum stills that are good for c1d2 or c1d1 hazardous environments for several years now.  That business is growing very quickly right now and within the next 1 to 2 years it will start surpassing ADEs yearly sales.  This equipment is mainly for producing CBD oil from hemp, but can be used for removing oils from many other types of plant materials.  Also my equipment can be used to crack those oils into their particular components.  For example:  Hemp oil extracted using my vacuum wash system, my dewaxing system, then my ethanol reclamation and oil concentration vacuum distillation system can then be placed in my  fractionating (cracking) column vacuum still and can be broken down into a 99% CBD isolate and all of the known separate terpenes can be fractioned out.  At the Ark-la-tex cannabis business trade show last week I vaped some clear CBD isolate that had been thinned with a terpene isolate that tasted just like watermelon.  In fact it was one of the best watermelon flavors that I have ever tried.  My business is the only one that sells this type of equipment in 3 states here. Right now that industry is ready for a huge amount of growth with hemp legalization having occurred in my state of MO and the neighboring states of OK, AR and KY.  The US government just removed hemp from schedule 1 a few days ago.  Hopefully cannabis will be removed within the next year.  

To answer your last question.  Where spirit vapors or liquid ethanol are normally  present I would only use float switches and temp probes that are rated explosion proof.  If you do otherwise, you are asking for trouble.

[richard1]

Thanks @Southernhighlander and @starcat and @silk-city-distillers.

 

All instrumentation that I am doing is low voltage (24VDC)