I wanted to re-use by washers, but they were damaged pretty bad when I finally got them out with a curved needle nose plier. I figured since I'm going through all this work to tear her down, might as well build her up with new ancillary items (washers, gaskets, etc.).
There's no way to salvage them, lightly reflatening them out?
I've been reading that I can skip using copper crush washers and use teflon on a BSPP fitting.
It may or should work if you have enough teflon tape &/or some plumbers "pipe dope" on the threads to provide enough resistance to make a reasonably tight alignment angle fit for the OPV.
But I always thought that BSPP fittings need to seal with an o-ring or crush washer.
That's true as the thread is indeed parallel & not tapered like a pipe fitting. The OPV will seat & seal up against the crush/alignment combination of copper washers & the OPV's flat internal shoulder.
You've been very helpful with the measurements Craig(A). Now I see why many geeksters have a 2nd backup machine, as I've been coffee-less for several days now. Yikes!
Thanks Gabe, I always do my best to offer assistance when needed. {;-)
P.S. If you can't salvage the washers, maybe try one of the online vendor sponsors here (or others) & see if they can help out a fellow Coffeegeek with a few spare washers mailed out in an envelope by USPS. {;-D
With regards to concerns about temperature with the internal PID install:
chiil, I mounted my PID controller exactly as you did it. When speaking with Jim Gallt, I had a similar concern about the internal temperature harming the electrics. However, my Watlow SD3C controller is rated for 149 degrees F, and I think you have the 935 model, which should be rated similarly. Watlow controllers evidently can handle higher heat than others out there. Jim did some measuring with a thermocouple and found that the electrics do not approach their heat limit inside Silvia until you switch to steaming. During steaming, the hottest it gets is 150 degrees, oops 1 degree beyond the rating. So, things look manageable even without insulation. Nonetheless, Jim instructed me to raise the "cup warmer" top panel a little with some neoprene washers/spacers. That way, heat can escape more readily from the top.
My idea, which I will implement this spring when I have more time, is to cut a grate pattern or a hole with a grating installed between the grouphead and steam wand on the bottom panel. I will then mount an AC fan internally over the grate to take in air from underneath and get it circulating upward to cool the electrics. I think it will probably work better than insulation.
p.s., JeepinGeo and I are still working on the mounted pressure gauge. That guy has made lots of progress, so I should be able to post more about his design soon in these threads:
..When speaking with Jim Gallt, I had a similar concern about the internal temperature harming the electrics. However, my Watlow SD3C controller is rated for 149 degrees F, and I think you have the 935 model, which should be rated similarly. Watlow controllers evidently can handle higher heat than others out there. Jim did some measuring with a thermocouple and found that the electrics do not approach their heat limit inside Silvia until you switch to steaming. During steaming, the hottest it gets is 150 degrees, oops 1 degree beyond the rating. So, things look manageable even without insulation. Nonetheless, Jim instructed me to raise the "cup warmer" top panel a little with some neoprene washers/spacers. That way, heat can escape more readily from the top.
For the benefit of folks who might be considering doing an internal mount, we should probably also list the cautions I hope I mentioned to you.
It is hotter inside the Silvia than you would really like it to be for electronics. The Watlow controllers are spec'd to tolerate it better than some others, but heat is not good for any controller.
I, and several customers, have had good success with controllers mounted internally. But I have always warned them not to fall deeply, hopelessly in love with their PID because too much time spent at elevated temperatures may mean a premature end to the relationship.
Replacing a toasted controller might not be the end of the world for your or for me. But a person for whom it would be a traumatic event should probably mount their PID in an external enclosure where it can be isolated from the heat of the boiler and group.
We will continue to support internal mounting as an option for customers - but only after they listen to, or read, this little speech.
sorry, Jim, I didn't mean to paint a picture of internal PID eutopia. Just that life seems pretty good with the internal controller, and I plan on adding a cooling fan to help prolong the life of the electronics. But yes, I understand that things are hot inside Silvia for the PID, hotter than it would be mounted outside the machine, and hotter than would be ideal. And, yes, other people should understand this too. Nonetheless, your measurements seem to indicate that this is an option for those who accept these conditions. Or for those who plan on installing a cooling fan. =-)
GabrielB Senior Member Joined: 27 Mar 2007 Posts: 232 Location: Chicago Expertise: I live coffee
Espresso: Maver Junior (HX), Silvia... Grinder: Wega Max (K6), Rocky Vac Pot: Bialetti Moka & Brikka Pot
Posted Sat Mar 1, 2008, 5:18pm Subject: Re: Silvia Modification & Cleaning
Well, I finished up the work on my machine today. No leaks (as of yet), pressure gauge works like a charm and I have no need to change the OPV setting. The brew gauge reads 10 BAR with a blind portafilter, and while pulling a shot, it's at about 9.75 BAR. I think I'll leave everything as is for now.
Decided to put in a 1/8"M x 1/8"F x 1/8"M BSP fitting between the OPV and brass adapter for the teflon line. The fitting was a royal pain in the a*s to get, not to mention the wait. I used a Quickmill pressure gauge purchased from Chris Coffee.
I had plans originally to add a coiled copper passive inlet heat exchanger, but it was getting a little cramped inside the Silvia. Plus, I'm not sure how much it would have helped. The low water LED was a nice little add on that I've seen before on this site.
Nice work, Gabe. I am in the process of figuring out the pressure gauge. You would be more than welcome to post your list of parts and your method for this mod on this thread:
I am very impressed you got it working, and if you had time, a walk through of your process would be much appreciated in one of those threads. My CoffeeGeek bud, George, is very close to having the mod complete, but having your insight would also be very useful.
Also, do you know how high a temperature the QuickMill gauge is rated at?
I got one rated at 140 F from the gaugestore.com. It's a larger diameter at 2". Before I cut the hole, I want to know I have the right gauge. But we can always move this discussion to the threads I posted above.
I'll go ahead and post the steps in this thread and we can throw the links the two aforementioned threads. I have some pics that will show the internals at my flickr account (signature). I ended up using the Quickmill brew gauge from Chris Coffee, which is the same brew gauge used on the Anita and possibly some other machines. Regarding the temperature rating, I didn't check. I assumed if it's good enough for an Anita, it's good enough for my Silvia. Be sure the gauge comes with the copper capillary tube. Also, when ordering online through their site, make sure you add a note stating that it's the brew gauge and not the boiler gauge. I had a mix up occur when they shipped it out, but Chris Coffee did an exceptional job of sending out the correct gauge. They even threw in the gauge mounting bracket for free as compensation for the error, which I had completely forgot about. This holds the gauge in place from the rear. Also, I won't go into detail about BSP fittings (threaded, parallel, metric, etc.). All I know is that it was a pain to find the correct tee for this application as most US hardware stores only carry NPT fittings.
Items purchased: Quickmill brew pressure gauge with copper capillary tube and mounting bracket. The mounting bracket will need to be bent a little for it to work on the Silvia, otherwise you won't be able to screw on the copper capillary tube. Drill bit large enough for a pilot hole (I don't remember the drill bit size off the top of my head) 1/8" MALE BSPT x 1/8" FEMALE BSPP x 1/8" MALE BSPT, NOTE: longest lead time item, 2 weeks 6mmx4mm teflon tube PTFE food safe - McMaster Carr P/N 52335K34 (optional since you can cut off the ends of the old tube) Teflon tape Sand paper for gripping the teflon tube Other basic tools (pliers, wrench, screwdrivers, etc.)
TYPICAL DISCLAIMER: DO THIS AT YOUR OWN RISK. YOUR WARRANTY WILL PROBABLY BE VOIDED, ETC. THESE STEPS ARE OFF THE TOP OF MY HEAD AND SHOULD BE USED AS A REVIEW. MY SILVIA WAS COMPLETELY TORN DOWN WHEN I INSTALLED MY PRESSURE GAUGE, SO THE INSTALLATION MIGHT HAVE BEEN SLIGHTLY DIFFERENT.
Now on to the good stuff...
1) I won't go into too much detail, but there should be some steps out there on how to remove the stainless steel panels, etc. You'll want to completely remove the front stainless panel so the appropriate hole can be cut out. You can use the MLG PID installation guide if you purchased the PID, as he did an excellent job of tearing down the Silvia. Make sure you take lots of pictures of which wires go where.
2) I purchased a punch kit from Harbor Freight which was in the neighborhood. It's a cheap set, and I actually ended up bending the smaller driving screw. I bought a drill bit (to drill steel) that was large enough to allow the small driving screw to feed through. Next, using the small driving screw and what I believe is the 3/4" die, I punched out the first small hole. Make sure everything is aligned properly, otherwise you will bend the screw. If it's being driven in crooked, start over and offset the die 45 degrees so the teeth can dig into fresh steel. Now you should have a hole that is large enough for the bigger driving screw included in the set. Next, punch the last hole using the 1 1/4" die using the large driving screw. Same applies, make sure everything aligns properly as you drive the screw, otherwise, rotate the die 45 degrees to start over. Once complete, I ended up dremeling the edges a bit to get the gauge to fit properly and remove any sharp edges. Also, make sure the mounting bracket is pre-bent accordingly for it to fit on the Silvia. If you don't feel comfortable doing all of this, see if a local shop can punch it out.
3) Now working on the guts of the Silvia. Try to purge as much water by steaming the boiler and open the steam wand. This will lower the boiler water level below the OPV height. Let the machine cool off completely before disconnecting anything. Now, the gauge will feed off the newly purchased brass tee between the OPV inlet and the brass compression nipple. Disconnect the teflon line and carefully remove the brass compression nipple from the OPV, without turning the OPV relative to the boiler otherwise it may break the seal. Apply a couple wraps of teflon to the male ends of the brass tee and the brass compression nipple and install the brass tee (pic). I hand tightened the brass tee until the male end for the gauge is facing up.
4) Next, pre-bend the capillary tube so that it will reach the newly added tee and the location of where the gauge will mount. Screw the capillary tube onto the brass tee, do not tighten down all the way yet. Now, reassemble the front of the Silvia, leaving some wires disconnected if it helps. Wrap some teflon tape around the male end of the gauge and feed it through the front. On the backside, feed the mounting bracket through and screw on the other end of the capillary tube. This is a bit of a pain. I used a 12mm wrench to hold the gauge in place while tightening the capillary nut with a 13mm wrench. Ideally, you will need two 12mm wrenches.
5) Next, tighten the capillary nuts down completely (don't over do it). If you are using the old teflon tube, cut off enough of the tubing so that it reaches the brass compression nipple. Remember, by adding the tee we will require less teflon tubing. Feed the brass compression nut over the tubing and connect the teflon tubing to the brass nipple. Use some sand paper to grip the teflon tubing and push it onto the nipple, it may be difficult to do so. Swear a couple times if needed. Don't use pliers. Once it engages, tighten down the brass compression screw.
6) Reassemble the rest of the Silvia and the wires. Refer to your before pics. Check everything. Go walk away for 10 minutes, come back and re-check everything.
I actually called my wife down to witness me powering on the Silvia. I plugged her in and powered her on. Wow, everything worked fine to my surprise.
"So, what do you think?" as I leaned against the counter showing off the modified Silvia.
"Ohhhhh... look at that! The clock turned out very nice!", turned around and she went back upstairs.
Cheers, Gabe
EDIT: I just want to note that the only reason I installed it this way was because I jumped the gun and purchased the Quickmill gauge. The Quickmill gauge has a BSP Parallel (BSPP) male end. If I had just purchased a gauge sourced with an NPT end, I could have just tapped into the teflon pipe using a compression tee from McMaster Carr. After using the gauge now for about a week, the needle is rock steady. This is probably due to the small capillary tube and the 5 or 6 coiled loops in it.
For all those concerned, I would like to say that read the brochure, and talked to Watlow technical staff today about the operating environment. The Watlow SD Series technical bulletin list the operating temperature range as 0F to 149F, and the storage temperature range as -40F to 185F. I asked the technical rep if there would be a "loss of life expectancy" if an SD controller were operated full-time in the 145F to 150F range day in and day out (never a fluctuation). He said no, that is why Watlow rates the SD Series for 185F storage temperature, but he did say that the Watlow testing etc.. showed that beyond 149F, there is a decrease in performance linearity.
So the story is - MOUNT THAT PID INSIDE!!! (if you like that location). The steam performance is not nearly as critical as the brew performance. So instead of a 2+/- 0.2F temperature stability, maybe it will be as bad as +/-0.3F for your steam control. I can live with that.
Of course this all assumes that the operating environment truly does remain at or below 150f when steaming. Any comments on that Jim?
Jim did some measuring with a thermocouple and found that the electrics do not approach their heat limit inside Silvia until you switch to steaming. During steaming, the hottest it gets is 150 degrees, oops 1 degree beyond the rating.
I placed a thermocouple inside to measure the ambient temperatures a couple of days ago as well. Hit the steam switch and let it sit for a good 15 minutes. It's true, the ambient temps during steaming are around ~150F, slightly exceeding the high end of what Watlow recommends.
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