Refrigerant Recovery Pump Updates

Some excitement for closed loop extractors looking for an electric refrigeration recovery pump rated for R-600 refrigerant and more good stuff from Haskel!

We are testing a electric new pump named the CMEP-OL that was designed specifically for our cannabis market, which is certified for use with flammable solvents, meets our process requirements, and has so far stood up to our field testing.

We just moved it to the third production lab for continued field beta testing, with a thumbs up from the first two, a note that they are quieter than either the Appion or the TR-21, and faster than two TR-21’s in both of their applications.

We are currently running it in the field in as continuous service as possible, to rack up hours and tests its ability to stand up to our use and abuse, and so far, so good.

We of course continue to recommend and rely on the pneumatic Haskel 59023 double stage and EXT420 single stage, which Haskel will now offer in a -2 configuration that is switchable from single to double stage using a single two way valve and two check valves.

WolfWurx already converts both of the existing pumps to selectable single or double stage, using two three way valves, which is more complicated, though ostensibly with less back pressure without check valves. At least one other operator I know has converted his to selectable stages, using four two way valves.

The Haskel’s single drawback is its air consumption, but we have exciting news! The first, but old news, was that the Haskel performs most of our tasks single stage, so we almost double the output, and now the new news is that we’ve also determined that the Haskel never requires its full rated 100 psi pressure or 40 scfm air flow to meet our performance requirements at their recommended 60 strokes a minute.

We don’t have enough back pressure on a Mk VB installation to require more than 50 psi even running single stage, so we end up needing only about 25 scfm at 50 psi, or about a 6.25 hp (7 1/2 hp) screw compressor, rather than the 10 horse required for full pump capacity.

The big difference that makes, is the selection of single stage screw compressors increases at 7 1/2 hp, and they use less electricity.

For smaller installations, many of us have searched for an electric oil less refrigerant recovery pump that is rated for flammable refrigerants, and many use the non NEMA 7 rated electric Appion G-5, the ProMax-6000, the CPS-TR-21, and TRS-21, simply because they work.

CPS delighted us recently with their offering of the TRS-21 sparkless, influenced by our markets needs, but not certified for use with R-290/600/600A. It currently appears to be struggling with infant mortality with the new pumps seals, and we await their solution.

Here at the Pharm, we’ve also tested the R-290/600/600A rated CMEP loaned to us by Ecogreen, which performed well testing machines, but alas was not oil less, and are now testing a CMEP-OL, NEMA 7 oil less refrigerant recovery pump on loan from

Here is a picture of four pumps, left to right, the Appion G-5, the CPS-TR-21, the CMEP-OL, and the CMEP.

The Haskel that follows, is on WolfWurx, Inc Mk V waiting to be converted to selectable single or double stage, with a picture following of a unit converted using two three way valves.

Zee Pumps-1-2zee pumps 001Haskel 59025-3

Haskel plumbed selective stage

Haskel 59025-3 converted to selectable single or double stage using two three way valves. Haskel offers the EXT420 single stage and soon will offer their EXT420-2, which is selectable single or double stage, using one two way valve and two check valves, engineering test sled picture below:

Haskel single-dual stage conversion

Haskel EXT-420-2 prototype test sledHaskel EXT420-2 prototype:

Wahoo, Wahoo!  Hee, hee, hee…………….


Lookacheer at whut Pharmgold is building a NEMA 7 Class 1 Div 1 6 cfm pump out of:

VaporHawg Pump innards

37 responses to this post.

  1. Posted by darrylboone on December 26, 2016 at 7:35 PM

    How many hours logged on the CMEP-OL HC refrigerant recovery machine before the bearing failed?


  2. Thanks, very informative


  3. Posted by Jiminy Cricket on March 8, 2016 at 10:05 AM

    greetings! great work!
    i was wondering if you could supply more info (pics, diagram parts etc) on converting the 59025-3 Haskel (or ext-420 or aa5-d etc) to two stage?
    thank you!


  4. Posted by baxterbixby on January 30, 2016 at 10:59 AM

    WHERE CAN I BUY ONE OF THOSE NEMA 7 Pumps from??? have a haskel and a huge air compressor now and would absolutely LOVE to switch to one of those!


  5. Any word on the cmep-ol from he’s testing?

    Also wondering about the cmep-6000 3hp unit?


  6. Posted by Vladislav on December 8, 2015 at 11:50 AM

    if you’re interested I can solve the problem with pumping pure butane. And prolong life. In my experimentation with the TR21, when replacing native piston rings, on the other their life increased by 10 times. Sorry for the bad english.


  7. Posted by Vladislav on December 8, 2015 at 9:11 AM

    Hello everybody. As I understood from the CMEP-OL there is a problem with the piston rings and they do not work for a long time with a pure butane. Correctly?


  8. Posted by Fuz on December 4, 2015 at 3:45 PM

    I’m looking to purchase a knf double diaphram explosion proof recovery pumps for a precision extractor and was wondering if there was any testing by you guys here . Thanks


    • Posted by Maj. Resin on January 6, 2016 at 10:41 PM

      Just got one, we will be testing it in the next week or so…if you can control the back pressure I hear it works efficiently.


      • Posted by Fuz on January 21, 2016 at 11:14 AM

        so i just received mine aswell and was hoping to see if you had possibly done any testing yet ? havent had any time quite yet to do any testing myself.


    • Posted by Darin on February 17, 2016 at 1:31 AM

      I was wondering if your precision extractor had the -50 chiller and how quickly it recovers. I’m doing my first runs with one tomorrow and they have claimed 45 minutes recovery without a mechanical pump.


  9. Posted by petger on September 10, 2015 at 1:35 PM

    How is the cmep ol testing coming along?
    Im looking to pick one up. Is a cold trap needed after the pump to cool down the gas before returning to the recovery tank?


    • Our CMEP OL test has gone well to date, and it continues to run without incident, so we will next tear it down and look inside for a look see.


      • Posted by peter on September 15, 2015 at 2:45 PM

        Thats awesome to hear. Im ordering mine this friday.


      • Posted by Dr heisenberg on January 30, 2016 at 11:11 AM

        I have a cmep-ol that I’ve been running since July 2015. I run it a min Aug of 10 hours a day some days longer. I’ve had very few problems. Recently the fan blade came disconnected…….I think the cmep-ol is the pump for this industry. Another thing I’d like to point out is that I run a very custom extractor and the distance from the bottom of your base and the pump output line and the length of hose on your vacuum side make a difference. I have a tall base and long lines. I’ve been cycling through 15 pound runs with 32 to 36 pounds of solvent in 2.5-3 hours a run…..


  10. Posted by Jon Bray on August 5, 2015 at 4:51 PM

    The haskel gas boosters have some blow by on every stroke. I don’t think it would be wise to run a gas booster indoors with anything explosive solvent.

    I can lose 10 pounds of Co2 in 2 hours through my haskel, and as it wears it will get worse.

    I run a Co2 safety alarms in my lab which will warn me when the PPM’s reach 1500, gives a visual alarm @1800 and a audible alarm @2000.

    Is there such a safety device that could be used in a Butane lab?

    In my other work with explosive solvents we had to have nitrogen purges hooked to the machine that would automatically purge the system with nitrogen if any safety parameter were to fall out of a normal range. The machine would not run if it could not get a positive flow from the nitrogen bottle on startup. That is a true safety, one that will not allow a operator to run fast and loose for even one cycle.

    With that being said people still burn down there business with explosive solvents because they use the solvents outside of their safe machine. All because it is quicker and easier to vent that to recover……. and then a spark!

    I hurts me to see people suffer needlessly.

    I also hurts to see a grass roots movement erode away as the mainstream adopt the ideas and use the products in masses.

    The days of small labs are numbered, the money is pouring in and there is no catching up. All of the industries that once turned a blind eye to the needs of the few in a passionate movement will “roll out the red carpet” for a legal cannabis industry. This will leave little room for the small guy to compete, some will survive but most won’t.


    • CO2 is a much smaller molecule than Butane and thus far we are not getting any discharge from the fail safe port between the two seals on the EXT-420. When we do, we will rebuild the pump.

      Good point on indoor leaks. We recommend indoor running, only in a properly set up extraction room, which has an HC alarm and ventilation capable of keeping any leaks below 25% of LEL.


  11. Posted by MoJoe on July 17, 2015 at 7:10 AM

    Just have to say, thank you GW for your wealth of knowledge, and being my “go to” when I need to resolve an issue, or solve a problem, with my day to day work flow. That being said, I’ve had experience with just about all the available electric pumps, available, that we as an industry utilize. The latest is the CMEPOl, I utilize home made dry sieve (4a) filters (made with sanitary fittings/spools) one pre CMEPOL to catch and hopefully clean any moisture pre pump, and then another post pump, for the same, and to clean gas pre recovery tank. After a day’s use, it’s astonishing all the carbon/articulate this filter catches, and if I wasn’t utilizing it, all this “crap” would end up in my recovery tank, to contaminate all
    Future runs… Have you come across this? Thoughts?


  12. Posted by AK on July 6, 2015 at 2:48 PM

    First of all GW , youre the man! Thank you for sharing your knowledge. Can you recommend the most economical compressor that will work for the Haskel EXT420 . I just dropped 3k on one so every dollar counts!


    • If you have three phase power, get a three phase motor, but Eaton makes a 7 1/2 hp rotary screw compressor with tank and dryer for under $7K that keeps up, and Chicago Pneumatic makes an economical one. We’ve had good luck with Portland Compressor off Sandy in Portland.

      Despite needing 40 SCFM at 100 psi, in our application, you only need about 25 scfm at 50 psi to run our process, so a 7 1/2 hp screw compressor should work. The 7 1/2 hp Eaton that we ran, kept the air at 81 psi, and the 10 hp Chicago Pneumatic kept it at 110 psi, while running unloaded part of the time.


  13. Posted by Nature Refined on June 16, 2015 at 2:46 PM

    That after running their CM-OL for a few hours it has blown the piston seals and sent black material into their product. They also said they’ve gone thru 3 units and even had an engineer look at one and he determined that the pump was designed with the intentions that the solvent would be carrying lubrication through the pistons helping lubricate them. Now I know everyone has different experiences and I’m still gonna do my due diligence and run the CM-OL and see how much use I get out of it. I am very interested in your continued updates of your testing and I will also share my experiences.
    Thank you all very much and stay safe!


    • I saw the pictures posted, and it is hard to do an analysis from a distance, so am only offering observations and guesses until I do an analysis.

      The glazed cylinders and deposits look exactly like some of the pumps I’ve seen that ingested cannabis oil and had been run hot and dry. No oil less piston pump will tolerate that.

      We just moved our test unit to the fifth lab for trials without any complications, and before passing it on, I alcohol swabbed the intake and discharge ports between three and four, to see if it had been compromised. So far none of ours labs have done so.

      We will tear ours down when it does fail, and do both a personal failure analysis, as well as use a certified forensic lab to identify any accumulated substances. At that point I will be in a better point to comment.


      • PS: That does however bring up an excellent point! The CM EP OL is faster than dual TR-21’s, which means the port velocities are higher and more likely to aspirate oil that is too close to the pump intake.


  14. Posted by Nature Refined on June 16, 2015 at 2:39 PM

    First I just want to say thank you to every one of you that has put so much dedication and effort into our beloved industry. Information that you provide is one of the most valuable resources that we have and you continue to help in so many ways. I run an mk4c from terrp extractors and I had a CM-EP and stopped use immediately after my first recovery and realized it had been contaminated by the hemp seed oil in the CM-EP. I just finally received my long awaited CM-OL only to hear from a local industry leader


  15. Morning Tim!

    An Apion G-5 works, but isn’t rated for flammable refrigerants and Apion management has made it clear that they want no part of our market.

    We are still in the middle of seeing how long it takes us to break our CM EP OL test pump, so its longevity has yet to be determined, but the CM EP OL is the only electric oil less pump that I am aware of, rated for our purpose today.

    With such a huge market window, that will no doubt change with more off shore offerings, as well as domestic manufacturers looking for ways to tap into the demand.

    The only time proven oil less pump that I’m aware of this gorgeous morning, is still the Haskel pneumatic, but it is an even larger investment bite to swallow.

    Peace, GW


    • Posted by tim roethler on June 15, 2015 at 2:37 PM

      GW, Thanks so much for the info, as always you are precise and honest, I think I will buy the Appion for a temp unit , and wait to save my pennies for the Haskell or CMEP when you guys finish your test runs please post. Thanks so much for all you do Tim


  16. Posted by tim roethler on June 9, 2015 at 1:31 PM

    GW, thank you for all of your hard work and reliable data, in this business it is hard to come by such clear and reliable information. I am to be at the 6/26 tranformintor class, stepping up from a terp III (wonderful machine)yesterday I toasted my promax 6000. I would love an explosion proof pump but I cannot afford the additional expense right now. would I be wasting my money on an Apion G5 ? Or should I just step up and buy the CMEP ?


    • Posted by Chris r. on June 21, 2015 at 3:37 PM

      What’s your thoughts on the cmep-6000


      • Posted by Austin on July 11, 2015 at 12:44 AM

        if you need to recover 100lbs of solvent in one go then its great, otherwise it is way overkill. its basically three or four CMEP-OL’s in series in one housing (i cant exactly remember how many)


      • I haven’t tried the four cylinder CMEP-6000, but understand that the CMEP-OL was designed after it. So far we are pleased with its performance, but haven’t crashed it yet and pulled a head to see what it looks like inside after a summer in the field, with multiple operators.

        If it is the same design and quality as the pump we are CMEP-OL we’re testing, its worth investigating further, and if someone will send us one to use and abuse, we will be happy to put it through its paces and report back.


        • Posted by Nick on January 17, 2016 at 7:04 PM

          So my cmep-ol just died! Tried restarting and it just sounds like it’s seized up. Ordered the rebuild kit and beginning the tear down as soon as it arrives. It was chugging merrily along and then made a strange noise and quickly stopped.


          • Posted by Nick on January 30, 2016 at 2:23 PM

            Ripped apart my cmep ol and it was the bearings that blew out on one of the Pistons crankshaft.

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