shadowfax wrote:Eric, I just looked at my plumb-in hose (pump side hose), and tested the correct end of it with some other fittings I have that I know what they are. contrary to what a guy at LM-USA told me ('straight pipe thread' or something like that), it seems the GS3 uses a 1/4" BSPP fitting on the pump (i.e. the pump is 3/8" F BSPP, and it has 3/8" M x 1/4" M BSPP adapters in the inlet and outlet). You need a hose with 1/4" F BSPP compression fittings on either end to go from the pump outlet to the mixing block, and remember that one side has to be 90° to go into the mixing block properly.

FWIW, Chris Coffee told me the input hose fittings are standard pipe thread, not BSP. They supplied me with an adapter from the input hose to a John Guest fitting, and claimed it's standard pipe thread, but I haven't checked to see what it really is (and I don't have any known BSP fittings here to test with anyway.) That, of course, doesn't mean that the output hose isn't BSP, as shadowfax says (or, for that matter, the input hose could be BSP as well -- maybe CC and LM have it wrong.)

There have been some changes to the output hose interface. My first GS/3, manufactured in May 2008, and the one I have now, manufactured in September of 2008, have a F-F adapter between the pump output adapter and the check valve, as shown in the following photo:



The parts catalog shows that these parts have been changed, and the F-F adapter has been eliminated:



Here's a picture of a GS/3 posted on Gs3cafe in March of 2009, and it doesn't have the F-F adapter:



I've wondered if the adapter, or lack thereof, might change the path length and angle of the output hose enough to affect vibration.

Whatever the answer, I'm not convinced that any manipulation of the output hose will ultimately make the machine not subject to periodic vibration. For that reason, when the warranty on my GS/3 is up, I'll seriously consider moving the motor and pump to the cabinet under the GS/3 (if I can figure out how to make enough room for them...) Just listening to the video posted by shadowfax is very convincing.

Peppersass wrote:FWIW, Chris Coffee told me the input hose fittings are standard pipe thread, not BSP. They supplied me with an adapter from the input hose to a John Guest fitting, and claimed it's standard pipe thread, but I haven't checked to see what it really is (and I don't have any known BSP fittings here to test with anyway.) That, of course, doesn't mean that the output hose isn't BSP, as shadowfax says (or, for that matter, the input hose could be BSP as well -- maybe CC and LM have it wrong.)

For what it's worth: The GS3's plumb-in hose has 2 different threadings on it. The first is (based on my testing) a 1/4" BSPP fitting that attaches to the pump's inlet. The other side is a 3/8" compression fitting that matches whatever the heck is under a normal kitchen sink in the US. I have no idea what that is exactly, but it's 'standard' and wholly immaterial if you're looking to, say, outboard your noisy pup, because you're looking to extend the hose between the pump and the mixing block. Both of these ends are 1/4" BSPP, and you will need a hose with that on both ends (alternately, you can do as I have done and use the supplied adapter from the pump (3/8" M x 1/4" M BSP) and use it to attach a very standard 3/8" F x 3/8" F BSP hose to the short hose going to the mixing block, and then using a 3/8" M x 3/8" M check valve on the pump outlet).

I just want to make sure no one is confusing the two ends of the GS3's plumb-in hose here. It's also possible that there's another 'standard' 1/4" threading that the GS3 uses that is virtually 100% compatible with BSP, which is what they probably ought to be using since they are Italian and all the other Italian espresso makers use BSP. That would be odd and stupid, but not outside the realm of possibility. However, I just want to say that I did take the 1/4" (it's smaller) side of my GS3 plumb-in hose, and I threaded it onto a 1/4" BSP male fitting that I happen to have in conjunction with my Elektra restoration project. It threaded on fully and smoothly. So, whatever the threading may in fact be, it will definitely be compatible with that.

Hi Dick,
The part you refer to as the F-F adapter is actually the check valve, in it's entirety. My machine came with a configuration similar to the 3rd photo you posted, and John Blackwell sent me one of those check valves to help extend the hose a bit. It didn't make a difference in my case.

To summarize, the brass and chrome adapter, in its entirety, between the output of the pump and the line over to the mixing block is the same check valve assembly John sent me.

I don't have this valve installed in my current, outboarded setup.

The F-F adapter (I believe this is called a coupling) is not the check valve or a part of the check valve.



The check valve above is the brass nipple (a.k.a. M-M adapter) with the up arrow engraved on it. The coupling is just below it. Kind of convoluted, they could have just put a 3/8" M x 1/4" F adapter in the pump outlet to begin with, rather than doubling that fitting in the already tight space; it sounds like they've corrected it now.

Alas, I defer to Nicholas. I just know the check valve assembly, as sent to me by John, contained both the brass and the chrome piece. I do know it has a different thread on the chrome piece that requires the use of a copper washer to get a seal.

Ok, so there, I think I added some worthwhile info to the thread.

Just a Note on the threading issue. The pump has BSP threads (Female 3/8 BSP). The check valve is 1/4 BSPP and both ends of the tube that goes from the pump to the inlet manifold are 1/4-BSPP. There should also be a hose included for water supply hook up. The pump end is 1/4-BSPP and the other is 9/16-24 UNF thread on the other end to connect to a standard 3/8" compression fitting.

Hope this helps,
Bill

Bill, Thanks for that info! My only other question is, do you have any idea how a guy would go about getting a long (say 48") braided hose that's got 1/4" F BSPP compression fitting with a 90° elbow on one end and a straight 3/8" BSPP compression fitting on the other? This would be a nice hose to have for my outboarding (it would eliminate the unnecessary junction that I have in there now), and might be handy for others who do the same.

shadowfax wrote:The F-F adapter (I believe this is called a coupling) is not the check valve or a part of the check valve.

Right. The reason I called it an adapter is because I disassembled the pump connections on my first GS/3 pump and had the silver part in my hand. It's definitely just a F-F connector. Now ask me how hard it was to get the parts back together again without leaking...

I realize this has been confirmed by BillC, but thought I would make a worthless post to prove that I knew that!

shadowfax wrote:Bill, Thanks for that info! My only other question is, do you have any idea how a guy would go about getting a long (say 48") braided hose that's got 1/4" F BSPP compression fitting with a 90° elbow on one end and a straight 3/8" BSPP compression fitting on the other? This would be a nice hose to have for my outboarding (it would eliminate the unnecessary junction that I have in there now), and might be handy for others who do the same.

What he said! I'd like to get a longer braided hose, too. While we're on the subject, what's the practical limit of such a hose? I've given some thought to locating my GS/3 pump in the basement, which would require a about 8-10 feet of hose. Aside from making it difficult to adjust the pump bypass valve, would a hose that long be a problem?

Ok - this is getting outta hand.
I hit "submit" and it shows me a preview.

I hit submit AGAIN and it shows me ANOTHER preview.

On the third try, it posts two entries (three's a charm I suppose).
This has happened three times in two days, from two different computers (one at work and one at home)