Making an Auto Draw Off

[Gary R]

A local syrup maker got me interested in this. He likes to find out how things work and build things. He bought a very popular auto draw off. He wants to make another one so he does not have to move anything when switching sides. He source the controller and I did the valve. Almost all the parts for these are off the shelf. The total cost in parts came to $187. For those that can build this it should be a fun small project. If you need to buy one, the past sale price on their "cheap" draw off is not a bad deal. This build will still require hand fitting and making an extension tube for the RTD. I have all the parts but haven't gotten it together yet.

Controller: http://www.auberins.com/index.php?main_page=index&cPath=1

The controller part#, SYL-2362 and RTD part#, PT100S. I also bought a flashing buzzer for the over temperature alarm and 10' of braided stainless RTD extension wire. They don't have 100 ohm RTD's with a long enough stem. By buddy made some out of 1/4" SS tubing and capped the end soldering SS. We used silicon and heat shrink tubing on the top where the wires come out.

Valve: http://www.hvacpw.com/SearchResults.asp?Search=VT2327G13B020&Submit=Search

The valve is a zone control valve for hot water heat systems. They also come in 1/2" and 1". The 3/4" one I chose has a water flow rate (Cv) of 8 GPM. If anyone knows where to source the SS "tee" type of valve, please let us know.

The box is a 4X4X4 plastic junction box. You can get it from a big box store for $7. I also bought a receptacle, switches, box connectors, grommets and wire. You will need to hand cut the box to fit the components. Be careful because it is tight. As with all draw offs you will still need to buy some plumbing fittings as needed.

It's back to cold weather some I'll try get this thing together. I hope this is helpful!

[heus]

Im interested in seeing how this works out for you. Keep us posted.

[Springfield Acer]

Hey Gary,
Is that an SYL 2362 instead of 2326? I looked this over and read the instruction manual. It sounds pretty impressive.
Do you have to fill the probe tube with heat transfer cement?
What is the stroke time on the valve? How fast do you need it to open and close?
BTW: Thanks for the help today!

[Gary R]

Heus, It should be just fine. It's the same parts they're using.

Springfield Acer, thanks for the correction. I must have miss-typed. I plan on using heat sink compound inside the tube to ensure good heat transfer to the RTD. I don't think it would be necessary though. The probe is in the pan all the time. It shouldn't see dramatic temperature variances.

I did get most of it assembled today. Hopefully we'll be back to boiling in a week.

[Dennis H.]

Cool, Thanks Gary.
That is the same PID controller I am using for the vac pump controller.
If you also look at Aubers Ins. They have some really nice connectors for the RTD probe. They are 3 pin push on and to remove you pull out on the outer barrel and it comes right off.

[Dennis H.]

Hey Gary as for the T type valve. I got a look at one up at LEME and it is a homemade valve for what I could see.
There is the SS T and the 1" barb fitting at the oulet. I am not sure where the solenoid part at the top is from but on the end of the plunger inside the SS T there is a silicone rubber cup thing that is inside the valves of coffe makers.
There really isn't much to them it just will be a pain to find the solenoid thing at the top.

[Gary R]

You could use just the controller and RTD as a temperature display and still manually draw off. The cost would be close to a 5" dial or good Hanna thermometer and you get to see the tenths of a degree.

Dennis, I have one of the 1" "T" valves. My friend gave me it to use. The top solenoid part is what I'd like to find. Looks like you have most of the parts right at home:)

[heus]

Gary two questions:
1. Could you use a probe off of another thermometer instead of the ss tube?
2. Does anyone make an rtd that wouls stand the temps of being used as a stack thermometer?

[JAMIE]

Auberins Instrument makes a controler and 6foot rtd cable and 4 inch rtd probe that goes into the stack.It also has a high and low temp alarm.Just picked one up for my rig. cheap $55.00 plus shipping....very nice.

[Dennis H.]

About the temp probe length issue. I could not find one that was long enough to use the 1/4" NPT fitting on the drawoff box, so what I was thinking was to make a bracket that the probe attached to and have the bracket made to hang from the side of the syrup pan. It would have bends in it so that it gets the probed alinged with the center of the pan right at the drawoff spot. Basically where the original probe tip was.
Quick easy to remove and I could hang it from the control box where it would be mounted.

[heus]

[QUOTE=JAMIE;203048]Auberins Instrument makes a controler and 6foot rtd cable and 4 inch rtd probe that goes into the stack.It also has a high and low temp alarm.Just picked one up for my rig. cheap $55.00 plus shipping....very nice.[/QUOTE
This one?
http://www.auberins.com/index.php?main_page=product_info&cPath=17&products_id=292

[Tweegs]

I’m curious as to why there is a need to extend the RTD tube.

I’ve read much in other threads that said the same thing, the RTD was too short.

I’m also rigging up an auto draw off (PID, RTD, SS Viton valve) of course the RTD is only about 4”, but I figured on just making a bracket that will work with the RTD I have.

The wire harness has a SS sleeve, I’m relatively sure the wire insulation will withstand the temps, so short of the bracket, I don’t understand the concern.

Can someone enlighten me?

[Gary R]

Heus, you would need to look at the RTD specs to see if it will handle the temperature. They do have type "K" thermocouple that is 1800* rated. These controllers need programed. You need to go through a menu selection and tell it what type of probe is used.

The probe length is a matter of fit and convenience. My evaporator takes a 9" probe to reach through the draw off box and into the syrup pan. I plan on keeping my 5" dial in it's place. So, my probe would need to hang from the edge of the syrup pan. It might be 12" to reach next to my dial tip. You could make a bracket that would lower the probe over the edge and into the pan. The probes are sealed and the wires are teflon, 400*? I just want to keep my wires out of the pan.

[Tweegs]

OK, that makes sense. Just wanted to make sure I wasn’t about to do anything really stupid.
I’ve done enough of that already. :lol:

[JAMIE]

Auber Thermometer Model AT100RTD...SORRY $57.00 NOT $55.00 .I am installing soon so i will have to play with it.

Just looked at the invoice and it says that it is item#AT100CHIM and yes i did pay $55.00.The probe as stated by another poster is a type K good for a max of 1800 deg F but i am not sure at what temp on the bottom end.Sorry for the confusion.The only diff from the one you found is the external buzzer as far as i can see.

[schmidt's]

Does anyone have a picture of the insides of a t type valve from the big name guys. With couple pics I'm sure we could figure out how to put one together. You can get coils at mcmaster or granger no problem.

[schmidt's]

Gary check grainger #6X543 for the coil. Its says it has a .531 hole and 1/4" pipe is about .520 to .540. So check your pipe size just to be sure.

http://www.grainger.com/Grainger/DAYTON-Solenoid-Valve-Coil-6X543?Pid=search

[Springfield Acer]

So, if you buy the Grainger solenoid, how will it work? Does the outer casing (1/4" pipe) have to be non-magnetic and the inner shaft be magnetic?:confused:

[schmidt's]

Yes that is exactly what I figured.

[Dennis H.]

From what I can see from the pictures that Gary has posted is that the only reason that the solenoid valve coil is mount so high is so that it will be above the liquid level in the syrup pan.
The coffee urn rubber cup seals the outlet and syrup remains above that, so depending on how deep you run your syrup pan there will be that much above the rubber cup in the T fitting.
So really there is other reason to mount the coil so high.

A question about that valve setup. It looks like there is a metal tube inside that plastic sleeve. Am I correct? Inside this plastic sleeve covered metal tube is where the plunger rides up and down.

Next question is how is the coil located on this tube? I know on a solenoid valve there is a groove around the top of the plunger where a clip on the coil snaps into to located and secure the coil to the valve body. So on the this setup is there a groove for the coil to clip into or is it just held in place by friction?

It looks that the only custom made piece of the setup would be the plunger, Metal rod with a special end on it for the coffee urn valve cup to attach to.

[Gary R]

Dennis,

The coil is held by friction. The plastic sleeve is what places it at the right height so when energized the magnetizm will lift the rod that is in the tube. The rod looks and feels like magnetic stainless. The tube has to thick enough to have 1/4" pipe threads cut on it. The end of the rod was turned on a lathe to provide something for the cup seal to hold on to.

By the way I have mine all done. I plumbed it yesterday and spent time reading the PID manual. I have it programmed I think:rolleyes:

[Springfield Acer]

I've shared this solenoid valve with Gary. The spec says 80*C but the picture says 155*C which I confirmed with the seller. Why wouldn't this work?
http://www.ebay.com/itm/3-4-Stainless-Steel-Electric-Solenoid-Valve-110VAC-Normally-Closed-Air-Water-/280859904727?pt=LH_DefaultDomain_0&hash=item41648e0ad7

[BRL]

Here is another one little less money. http://www.ebay.com/itm/3-4-Solenoid-Valve-120-Volt-AC-VITON-STAINLESS-S21V-/290525484398?pt=LH_DefaultDomain_0&hash=item43a4ab156e

[Dennis H.]

I have heard that they will work.
I have heard that you need to change the spring inside to a lighter spring and I also heard that these valves need to be mounted upside down because of how the liquid will flow thru the valve.
I am just repeasting what I have heard.

[Gary R]

Dennis which one did you hear will work or needs modified?

Everyone keep up the good work. We just need a couple of Guinea pigs to try the valves. Hopefully we can come up with a reasonable priced valve that is suitable for the product we are making.

[schmidt's]

I'm tring the second one in a 1" model. It's rated for 265 degree F. Going to mount it side ways because fluid flows up and threw by pressure when mounted upright. Sideways should allow free flow as long as it doesn't gum up. If it doesn't work I have all the parts found to make the big name guys valve will just have to order parts and a night in the shop.

[Dennis H.]

It has been some time now since I heard about the spring issue. I am almost sure it was from one of the major sellers on ebay. The person that I heard this from said they contacted the company and explained what the valve was going to be used for and they put a lighter weight spring in it for him.
I wish I knew who told me this or where I could find this info at, sorry.

All the stronger the spring needs to be is to keep syrup from leaking out of the valve. Since there is really no head pressure the spring doesn't need to be very beefy.

The biggest down side to these style of valves is the convaluted route thru the valve. There is a few places where sugarsand and niter can collect and possible cause the valve to "stick" open. Maybe mounting it upside down would help.

[Gary R]

I'm not sure if you guys know, but the valve I'm using (brass OEM), is to be mounted vertical. I installed mine that way. It should prevent sugar sand from collecting. It is real nice looking at those digital tenths of degree. Now instead of being transfixed on the dial thermometer, I'm waiting for that final tenth!

[Dennis H.]

Mounting it verticle should work.

[Gary R]

Here's the pictures of my finished unit.67556756

[heus]

Can we see a pic of how you mounted the thermometer probe?

[heus]

Dennis how do I connect the individual rtd wires to the little pins? Do they just push in or should I also crimp them? Sorry I dont have any pics. The connectors I am talking about are from Auber Instruments. They have a pin on one end and a barrel on the other that the wire slide into. Should I crimp these? Gary by the way the 8" rtd probe from Auber actually fits in my evaporator pretty well through the float box port. I still mounted it from the top though.

[heus]

Gary any updates on how the auto draw off is working?

[Dennis H.]

Hey Heus, I just noticed that you asked me a question about those connectors.
I soldered the wires to the small pins.

Sorry about that, I must have been boiling that day.

[Gary R]

It works great. I've boiled with it three times.

[OneLegJohn]

Gary check grainger #6X543 for the coil. Its says it has a .531 hole and 1/4" pipe is about .520 to .540. So check your pipe size just to be sure.

http://www.grainger.com/Grainger/DAYTON-Solenoid-Valve-Coil-6X543?Pid=search

Did you confirm this is the same coil for the Marcland Drawoff? I have smoked my coil....again.

[Gary R]

Nate, did you make one of these? I did not use the SS style valve because I could not come up with the parts. With solenoids there are important things to watch out for. The coil wattage must match the core that it is trying to lift. Also the core must be at a certain position within the coil when it is energized. I do not know the exact position, but for example, if you coil is 2" tall the core needs to be 1.5" into the coil. This will give you a .5" lift when energized. If the core is not far enough into the coil, when energized there is not enough magnetism to lift the core. Then the core does not absorb the energy and the coil burns up. Try lowering the coil.

[schmidt's]

John the most common reason for coil burn out is the plunger not coming all the way up to the plug nut(piece of metal uasually the same material as the core, crimped or fastened into the top of the core tube). Do you hear a metal on metal clink when you actuate the valve. If not clean the core tube. The core needs to come all the way up to disapate the energy from the coil or the coil will burn up. Are there any specifications on the coil you have so we can check to see if it is the corrrect size?

[Dennis H.]

Hey Gary, after talking to you this evening I looked more into the zone valve that you used.
I was mistaken on what type of valve it was.
I was thinking it was a solenoid type valve but what you got is a motorized valve that has what looks like a ball inside that is opened and closed by motor. Is that correct?

Did you buy it thru the link below or did you get it else where.
It looks like it is has female pipe threading on the valve, correct?

[Gary R]

I never took it apart to see what it looks like. I had someone refer it to a paddle valve. A motor opens it and a spring returns it closed.

[Sugarmaker]

Gary,
Nice looking build on the draw off system. You always amaze me! Great looking set up on the rig. You will like it!
Regards,
Chris

[cog1]

I've built two auto draws this season and so far they have been working very well. I also used the same concept and built a stack temperature control for a friend.

First build
7411

Second build
7412

Stack Temperature Controller
7413

Sent from my DROID RAZR HD using Tapatalk 2

[Dennis H.]

Ok I found in documentation it is refered to as a paddle type valve. Some of these zone valves have a ball that is rotated into a seat that seals off when closed. The paddle type is just that a flat paddle instead of the ball. basically the same thing.

I just got done looking at several different manufactures whole make zone valves and it does appear that the Tac Erie valve is one of the best for the price.
It also appears to be the fastest to open. That is one thing I was wondering about. How long to open. Some were saying about 60 sec. The valve that you have says about 25 sec to fully open. Granted you do not need it to be fully open for syrup to flow, but still quick. and a quick 9 sec to close. It uses a spring to close the valve.

I now think I have all the details worked out for the my drawoff build.

[Gary R]

Dennis, I have my hysteresis set for 0.0 seconds. I find that syrup flows about a second from when I hit the set point. It closes in a couple of seconds. My draws have been more consistent with the auto draw off. I can't see tenths on my dial thermometer.

Cog1, those look real nice. I need to label mine.

Sugarmaker, you need to thank Scott. He came up with the idea and most part numbers. He also urged me on to do it, something you'd do:)

[heus]

So how much cheaper was it to build this Gary compared to a $400 Guru?

[Dennis H.]

I have everything priced out at $195. Now that does not include shipping.
I will need to get some misc. fittings to hook everything up.

[Gary R]

I priced everything out to about $190. That included the shipping on the controller. The valve ships free. There is still the additional cost for the plumbing fittings. You would need to buy them extra for any draw off. I have not seen a Guru. This is to duplicate the Marcland. Theirs was on sale for $450. If your not skilled at building this type of device, that was a great price. A few years ago they were a lot more. I spent about 4 hours in front of the TV building mine.

[DanE.]

Hi all,

I have a question on the valves that everyone has used. Are these valve only open or only closed? Or is the amount they open be control by the PID?

Thanks,

Dane

[Marcland]

Hey, this is almost a direct COPY of the Marcland Economy Draw off. Even the labels are correct...wow!
Where did all your research and expertise come from???
This is usally how the Off Shore Manufacturers operate.... we do the research and development they copy and profit, nice going!
By the way if you need any nelp or questions answered...feel FREE to call Bob at Marcland.

[Teuchtar]

I used that miniature RTD connector from Auber. Last weekend I had a problem with the auber controller giving EEEE error, which I traced to that connector. I looks like a nice connector, but its not really robust for this farmer's fat fingers. So my RTD is now hard-wired right to the controller. I'll find another connector once the seasons over.
Also, I changed the RTD from 2-wire to 3-wire, and this really helped with troublesome drift of the finish temperature. Don't understand why yet, but the 3-wire new RTD is very much more accurate and stays on calibration. I'll ask the controls guys at work why this could be, if I can ever find time to actually get to work. This season's been keeping me away from my day job. Lukily, I bribe them all with syrup, so nobody minds.

[Dennis H.]

Which connector did you get from Aubers, there are 2 versions. A small one and then an even smaller one.
I have the larger of the 2 on my vac pump controller and have had no problems with it. It's the one that is maybe 1/2"-5/8" od.

[Marcland]

The third wire is for temperature compensation and lead length reistance balance.
Using two wires you will get drifting as the ambient temperature cahnges and the contoller warms up and cools down.
HERE TO HELP. :)

[Marcland]

As for your standard draw off valves...they are normally closed, and just on/off.
PID control os used for tougher, faster processes. Maple syrup production temperature is SLOW REACTING
and only requres on/off action to get great results. P I D is Proportional, Integral and Derivitve control functions
for the controller.....more than needed in syrup production. Set your controller to on/off and if possible set the hysterisis at 0.0.

[TheMapleMoose]

Has anyone tried the SS selenoid valves that were mentioned? like this one for example? http://www.ebay.com/itm/3-4-Stainless-Steel-Electric-Solenoid-Valve-110VAC-Normally-Closed-Air-Water-/280859904727?pt=LH_DefaultDomain_0&hash=item41648e0ad7
I'm not crazy about the way the fluid flows through it, but if someone has tried it I'd like some feedback?
I did find a ball valve, its alot more money, and has a 5-7 second open time and the max operating temp is 212F. http://www.ebay.com/itm/Electric-Actuated-Ball-Valve-3-4-Stainless-Steel-110-VAC-New-/281112082219?pt=LH_DefaultDomain_0&hash=item417395f72b
If the solenoid valve worked without any issues i would prefer to go that route, but I'm open to suggestions

While I'm thinking about it...is there an issue with line voltage interfering with the accuracy of the RTD probe? I plan to mount my control on the wall and run the RTD & valve power(110vac) to the evaporator via pvc conduit. Are there any steps I should take to isolate the RTD leads from the AC voltage or can they be run together in the same conduit?

[Romeo]

So far I have the syl-2362 Con. RTD 100s and Schneider 3/4 valve is this the way to go or is there any new ideas Has one tried that Stainless Valve ? Thank You Marty