one of the compression fittings on my expobar broke (again) during a ristretto just now.

i had to open it up to reattach (by removing the drip tray, which i hadn't done before ), and noticed something about the pump i never picked up on before:

its an ULKA pump, with a fluid-o-tech overpressure valve

this rings out to me for this reason: fluid-o-tech's have really odd fittings. every vendor makes note that the OPV fluid-o-tech makes will only fit fluid-o-tech pumps. there's a ton of brass and what seems to be welding , to get the 2 parts together.

which brings me to my question- should my pump need to get replaced at some point -- am i replacing the pump and OPV at once ? if thats the case, maybe i should just ditch that valve and upgrade it when i do a brew pressure gauge next month.

You're right about the oddball fitting. If it's what I'm thinking, the Fluid-O-Tech OPV has 12 mm straight metric female threads for the inlet and standard 1/8" BSPP female threads on the outlet.

The adaptor has, naturally, 12 mm straight metric male threads on one end and 1/8" BSPP male threads on the other. This adaptor is, to the best of my knowledge, only stocked by Expobar dealers as there is nothing like it in the world of fitting and adaptors elsewhere.

Eric S.

2xlp wrote:am i replacing the pump and OPV at once ? if thats the case, maybe i should just ditch that valve and upgrade it when i do a brew pressure gauge next month.

Check out this document: http://myweb.tiscali.co.uk/coffeetime/_sgg/m1m4_1.htm. Apparently the fluid-o-tech relief valves aren't so great. It would not be a bad idea to replace it with something more durable if the pump went out. I believe EPNW sells the new Silvia OPV as a separate part.. or you could do what I did and order a relief valve from McMaster-Carr, part no. 4612K16 + appropriate fittings and put one of those in there. It's made a great addition to my previously unregulated machine, but it was a heck of a job to fit in there!

I just read Eric's post. Only the Italians would make something with 12mm metric threads for 9 bar pressure... Some of those espresso machine fittings are just ridiculous.

oofnik wrote:It would not be a bad idea to replace it with something more durable if the pump went out. I believe EPNW sells the new Silvia OPV as a separate part.. or you could do what I did and order a relief valve from McMaster-Carr, part no. 4612K16 + appropriate fittings and put one of those in there.

Both of those are dirty hacks. The Silvia OPV has some odd structure, and is designed for the silvia. The McMaster one doesn't say if its food safe. $30 from Chris Coffee gets the one on all his machines -- its pretty sweet. CafeParts.com and espressoparts both stock several dozen versions too.

oofnik wrote: It's made a great addition to my previously unregulated machine, but it was a heck of a job to fit in there!

yeah, i'm splicing a new pressure line into my isomac. i need to move a ton of stuff around to get things to right.

oofnik wrote:I just read Eric's post. Only the Italians would make something with 12mm metric threads for 9 bar pressure... Some of those espresso machine fittings are just ridiculous.

i'm sure fluid-o-tech had some reason for making the valve. i can't imagine why expobar chose that valve with that pump though -- there are so many valves on the market that wouldn't require adapters.

i think i might grab a dual gauge and new OPV online somewhere, and plop that onto the expobar when i open it next.

what can i do to reduce future issues?

jon

You could replace the OPV you have with the one used by Expobar now and mentioned in the article. It fits firectly onto the ULKA with no adaptors or anything else and will certainly prevent any future problems. I used PTFE tape to fit them, as it's easier to work with than threadlock, easier to undo and less likely to leak (in my opinion).

If you can't buy the OPV from Expobar, you could always see if http://www.bellabarista.co.uk/ would post one to the states. It's very small, so I can't imagine postage would be very expensive?


Dave

P.S. When you repair the high pressure line, don't tighten it too much, thats what I think makes them let go.

DaveC wrote:You could replace the OPV you have with the one used by Expobar now and mentioned in the article. It fits firectly onto the ULKA with no adaptors or anything else and will certainly prevent any future problems.

can you please help me out?

i have the OPV on the far left.

you are telling me the one in the middle can go in without adaptors?

how can this be true? the one i have now has a female end. the one in the middle is male. not sure how that would work out with out some kind of adaptor.

thanks.

jon

RegulatorJohnson wrote:image: http://www.home-barista.com/forums/userpix/1131_picture1_1.jpg

can you please help me out?

i have the OPV on the far left.

you are telling me the one in the middle can go in without adaptors?

how can this be true? the one i have now has a female end. the one in the middle is male. not sure how that would work out with out some kind of adaptor.

thanks.

jon

Probably because the adaptor is still attached to the pump with threadlock. The one on the middle fitted fine once I had removed all the adaptors. I can think of no reason why your machine would be any different. The photograph below shows the very adaptor that needs to be removed in between the pump and the OPV. This then leaves a female on the pump connecteding to the male on the OPV.

ahh.. i see.

there is an adaptor aldready in there.

does this look like a good replacement? seems like it would work, yes?

http://www.chriscoffee.com/products/home/isomacparts/replacementexpansionvalve


thanks.

jon

i bought one of those from chris coffee to retrofit my venus

it will work, but there are some things you need to know about it:

a- its big. the t bar on it is 1.5" across, the height from the valve's barb to the t's bottom is 4". so you need about 5" clearance. on the expobar, it shouldn't be a problem. on venus/silvia, etc, its a tight fit.

b- the T has 2 male fittings. that means you likely need some sort of coupler. the issue though is that couplers are made with similar threads (i'd love to see one with reverse threads on one side ) -- so its just a PITA to splice in. you may need to get some various fittings to get connections right.

that said, the $30 opv from chris is pretty solid, and comes mostly ready to splice into a line.