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Installing thermosyphon restrictor on expobar office pulser

Postby RegulatorJohnson on Tue Jan 02, 2007 6:57 pm

hi.

i have been unhappy with my 220° grouphead on my expobar.

i researched and found about the thermosyphon restrictor that can be inserted in the thermosyphon to make the group cooler.

i received a new smaller restrictor from expobar australia.

this may sounds like im being lazy but, i need some help determining the size of some fittings inside my machine.

i will need to purchase some new wrenches to fit the fittings marked below.

can someone please let me know what size these might be?

Image

im sure i can figure it out by measuring it from my adjustable wrench then going to buy a real wrench and hoping it fits then making how ever many trips needed to the store to get the correct size.

your help is greatly appreciated.

thanks.

RJ
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Postby jrtatl on Tue Jan 02, 2007 11:42 pm

Hi RJ,

Sorry I can't help with the sizes at the moment, but I just wanted to speculate that if your group is at 220 degrees, you might have the pstat tuned a little high.

I own an "older" Expobar from 2000, and although I've never actually measure the temperature of the "grouphead," I feel that 220 seems a little high for an Expobar.

Good luck, and keep us posted.
Jeremy
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Postby RegulatorJohnson on Wed Jan 03, 2007 12:58 am

the p-stat is at its original factory preset.

i know this because i noted its position as well as the pressure range it runs at.( .9-1.1 ish bar) i have moved the p-stat actually down to lower the temp. then back up after i got erics TC adaptor installed.

after one hour of idle my group temp measured by the TC in the group is 219-220°.

i contacted expobar spain about this and my excessive flushes to cool the group. they told me to contact the retailer (WLL).

WLL told me that there is not a thermosyphon in the group. and that i should contact expobar directly.

i gave up.

HB joe posted his introduction thread and i decided to try again.

whole latte love/ joe told me it was because im at altitude 4500/ft . a boiler at pressure is still at pressure no matter where it is correct?

this has been a process taking more then 8 months of research on my hot group head. i have read post after post and eventually tracked down a lead at expobar australia.

expobar australia, immediately responded and said they install these smaller restrictors in the thermosyphons of their machines. they even sent me a restrictor no charge with installation instructions.

this leads me to where i am at now. with a restrictor waiting to be installed.

the new restrictor should make the group 93° C . this is what expobar AU told me. seems fine to me. i dont pull that many shots. and if 93° is a bit cool it seems like can raise the p-stat a bit.

this should eliminate extensive flushes. but not flushes altogether. it is an HX after all.

thanks.

jon
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Postby 2xlp on Wed Jan 03, 2007 2:37 am

RegulatorJohnson wrote:the p-stat is at its original factory preset.


that means nothing. they don't really set up / burn in / test / check / tweak things at the factory.

two friends got a brewtus in the same week, brew and pstat were waaaaay waaay off from one another.

RegulatorJohnson wrote:after one hour of idle my group temp measured by the TC in the group is 219-220°.


what's the boiler at? can you lower it and still get good results?

RegulatorJohnson wrote:i contacted expobar spain about this and my excessive flushes to cool the group. they told me to contact the retailer (WLL).

WLL told me that there is not a thermosyphon in the group. and that i should contact expobar directly.

i gave up.

yeah, i once got a tech at aabree tell me that my venus didn't have a 3 way valve and that the pressure release valve was designed to not go below 14 bars on purpose (it would fall off on anything below 15). i gave up too.


RegulatorJohnson wrote:whole latte love/ joe told me it was because im at altitude 4500/ft . a boiler at pressure is still at pressure no matter where it is correct?

its a closed system. you should be flash-boiling at a lower temp if you drain hot water or when it hits the puck -- but thats it.


RegulatorJohnson wrote:expobar australia, immediately responded and said they install these smaller restrictors in the thermosyphons of their machines. they even sent me a restrictor no charge with installation instructions.

would you mind posting a few images of it ? just wondering. my expobar is getting an overhaul in the near future, as soon as the isomac gets put back together. might be fun to source one of those off another model.
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Postby erics on Wed Jan 03, 2007 11:15 am

I think your best bet is to either "measure" with your adjustable wrench or make a call to WLL service department. The correct type of wrench to use on these fittings is what's called a flare tube wrench or just tube wrench. Obviously you may be able to get by with a simple open end wrench.

Keep in mind that while your first guess might be that this requires a metric wrench, such may not necessarily be the case because these are all BSPP threads and fittings in the particular area of concern. My GUESS would be 7/8" or 22 mm. I'm fairly certain that the tube size into and out of the GH is 12 mm on your machine and the fittings at the boiler end would be as shown on diagram 9 on parts sites such as this:

http://www.vanelis.com/pdf/vACCESSORIES.pdf

I do not see the fittings at the GH end but they are the male version of the ones at the boiler end.

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Postby RegulatorJohnson on Wed Jan 03, 2007 11:17 am

that means nothing. they don't really set up / burn in / test / check / tweak things at the factory.


it means i havent changed it.
it means i havent turned it up REALLY high to get more steam or something.
it means that i havent messed up the temps by altering the setting my self.
it means that if it is running hot (which it is) that it is like that from the factory.

two friends got a brewtus in the same week, brew and pstat were waaaaay waaay off from one another.


this means that expobar probably has not-so-strict QA/QC guidelines.
my steam and hot water knobs were reversed. no big deal.
my expobar badge was installed upside down. no big deal.
what else could be missing or improperly installed in my machine? a thermosyphon restrictor missing or not installed correctly could do the same over heating issue.


what's the boiler at? can you lower it and still get good results?

the only way i can tell boiler temp is by a physics formula, or by using erics TC. i can lower the temp. see OP. this also lowers steam pressure, etc. i assume that the HX water is slightly cooler than the steam boiler.

IMO cooling something down with something hotter than the first thing makes no sense. heating up something with something hotter than the first thing makes sense.

yeah, i once got a tech at aabree tell me that my venus didn't have a 3 way valve and that the pressure release valve was designed to not go below 14 bars on purpose (it would fall off on anything below 15). i gave up too.


me too.


its a closed system. you should be flash-boiling at a lower temp if you drain hot water or when it hits the puck -- but thats it.


yes it is. yes i do. but im still flash boiling at 204° due to my altitude. i still flush until the proper temp. waste of time? yes. waste of water? yes.

would you mind posting a few images of it ? just wondering. my expobar is getting an overhaul in the near future, as soon as the isomac gets put back together. might be fun to source one of those off another model.


of course. i will be taking pics with a ruler for scale and probably compared to the original one.

in fact i will be producing an entire novel on my journey , before and after notes on temp and such. i just dont really know enough yet, im learning.

the guy at EX/AU says its the style that they like in aus. to brew cooler. this is why they use them down there. i am certain this will change the performance of my machine, thats the point. this must be a big enough issue for them to take the time to put them in there. also he knew exactly what i was talking about and how to fix it. i must not be in a unique situation. this is not something i made or found or got from a different machine. i got it from the OEM, i assume it is an OEM part, :D

i will not change any settings other than installing the smaller restrictor.

the thing that will be fun is to finally see what is or isnt in there now.

1. no restrictor.
2. restrictor that got moved somehow during shipment.
3. restrictor in there ok and it just needs a smaller one in there.

thanks for the help.

jon
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Postby RegulatorJohnson on Wed Jan 03, 2007 11:25 am

erics wrote:I think your best bet is to either "measure" with your adjustable wrench or make a call to WLL service department. The correct type of wrench to use on these fittings is what's called a flare tube wrench or just tube wrench. Obviously you may be able to get by with a simple open end wrench.


if they told me that descaling will void my warranty i wonder what doing this will do to my warranty? it did expire on 11/29/06 if if didnt expire when i put in your adaptor ;). so im not worried too much.

Keep in mind that while your first guess might be that this requires a metric wrench, such may not necessarily be the case because these are all BSPP threads and fittings in the particular area of concern. My GUESS would be 7/8" or 22 mm. I'm fairly certain that the tube size into and out of the GH is 12 mm on your machine and the fittings at the boiler end would be as shown on diagram 9 on parts sites such as this:


this is why i came here to ask a stupid question. i heard about the BSPP fittings issue, realized i need more research. there is a old mom and pop plumbing store that i like to support, maybe ill take my gutted machine down there and buy the wrench. seems like after i get the correct tool it should be easy to complete.

will read --> http://www.vanelis.com/pdf/vACCESSORIES.pdf

is it safe to assume that my GH is similar enough? i guess this is why you sent me there?

I do not see the fittings at the GH end but they are the male version of the ones at the boiler end.


FWIW i can see them. and it appears you are correct.

thanks again!

jon
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Postby 2xlp on Wed Jan 03, 2007 11:53 am

RegulatorJohnson wrote:it means i havent changed it.
it means that if it is running hot (which it is) that it is like that from the factory.


well yes. that's what i mean. they tended to run obscenely hot from the factory for a while - just about everyone getting one was lowering the pstat quite a bit. sure , there's less steam power -- but for a lot of people there was just way too much to begin with. if you're running that hot, i'm guessing you can drop your pstat .1 or .2. try testing the boiler temp with the tc or using the physics formula on boiler water.


RegulatorJohnson wrote:what else could be missing or improperly installed in my machine? a thermosyphon restrictor missing or not installed correctly could do the same over heating issue.

that's assuming that a restrictor was meant to be installed on your machine. expobar changed the model specs A LOT over the product cycle, and didn't tag anything with a revision number.

i think the most likely thing is that your pstat was set too high at the factory. everything that you're saying, to me, points to a much higher boiler temp than needed. you're not just cooling down the brew group when you flush, but the entire hx path too -- which is a lot of work.

try lowering the pstat a bit. that might solve a ton of issues.
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Postby RegulatorJohnson on Wed Jan 03, 2007 12:43 pm

2xlp wrote:try lowering the pstat a bit. that might solve a ton of issues.


i have lowered it. at that point the temp was only a couple of degrees cooler but the HX water temp only changed slightly. i still need to make milk drinks and it could barely swirl ~4oz of milk. i tried 2-hole tip. and i dont like the angles that it directs the steam. and it was too fast. different story. anyway, judging by the change in temp vs the change in steam from turning the p-stat down, i would have to basically not steam milk anymore. not a big deal but i still cant wean the wife off them little caps and i like to make what i call "big macs" (1/1 espresso and half-n-half microfoam, ~4oz-ish) so i need some steam.

anyway. it was early in my espresso life cycle so i decided to just go back to the way it was for a bit, leave it all stock and learn about the machine, then modify settings and stuff. this path allows me to, later on/now, not only change the settings but i can understand what is happening, inside the machine and inside the cup.

i could go lower on the p-stat and use a 2hole tip with different angles. why is this not the solution that expobar australia chooses?

me in email form on expobar australia website wrote:hi.

I am in america, i own a expobar office pulser. it seems to run very hot. i think the thermosyphon restrictor is either not there or its got a hole thats too large. i have read on coffeegeek.com and home-barista.com about an australian expobar rep helping someone out with a similar issue.

thanks.

jon



Expobar Australia wrote:Hi Jon,
Yes what you are saying is correct, there is a smaller restrictor available for these machines. Here in Australia we modify all machines to a lower temperature to suit our coffee blends, therefor no need for long water flushing of the group to drop the temperature. Please confirm your address and we shall post you the part required with some instructions on how to replace this part.
Kind Regards,

Expobar Australia



i think in the end i may end up with the restrictor in there and a slightly lower pstat setting.

im learning that there are a few different variables that can help control these temps. each with their own pros/cons. less steam and less flushing, more steam and more flushing, etc etc ad umforever.

thanks for your help, i really appreciate having access to everyones knowledge. hopefully i can give some back.

jon
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Postby 2xlp on Wed Jan 03, 2007 1:35 pm

ah, i didn't know it was that low already (that you could barely swirl milk)

i lucked out... i bought a refurbished and barely used expobar office control for ~500, from a repair tech who replaced all the crap parts in it with commercial ones (like the pstat, relay, etc). new, it probably would easily be worth the current pricing on expobars (which is just waaay too much)
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