DigitalDave wrote:I originally hooked up my new La Spaziale with no regulator, 80psi. I have a regulator on order, but won't get it till next week. I read that the pressure input should be 25-60 psi, but do not understand why. Will I hurt the machine or pump by connecting it this way for a short time, or is this a completely newbie mistake that will cost me? Can someone explain this to me?

Hi there:

It didn't seem like a major part of the answer was clearly stated, although it was alluded to. Discharge pressure in the rotary pumps I have seen is established and tweaked by adjusting the spring pressure against a relief valve plunger that opens up when sufficient force is applied to it. In the pumps that I have had experience with, it's the difference in pressure between inlet pressure and outlet pressure that provides the force to open the plunger, not the pressure with respect to ambient pressure. As an example of how the pump produces 130 psi, imagine that the pump relief valve may be adjusted at the factory to open at 100psi differential between inlet and outlet pressure, with the inlet pressure being at 30 psi with respect to ambient. That makes the outlet pump pressure with respect to ambient equal to 100 plus 30. If you then take the pump and hook it to a water supply with 80 psi pressure, the pressure produced at the pump outlet will be 180 psi with respect to ambient. Since brew pressure is with respect to ambient, you have to consider the inlet pressure and inlet pressure variation when setting up your machine. A good regulator setup controls both, although I can't tell you to what level a single stage regulator controls fluctuations.

-Greg

westland wrote:I agree ... you can get one on eBay for around $50 (see the image, and the gauge comes with it, and connectors come in all sizes and configurations) ... they are much more reliable and robust than the plastic ones, which malfunction with regularity in my experience

If you are buying an inexpensive brass regulator chances are it is made in China. I would definitely make sure it is Lead Free. Otherwise spend a little more for something like this: http://www.watts.com/pages/_products_de ... p?pid=6814

JohnB. wrote:Mine is 3 years old with no issues & as long as it doesn't freeze or you don't over tighten a fitting I don't see why it would crack.

Mine cracked on a seam near a fitting that I never touched - it was a plug of some type IIRC. It was a mfg defect, not user error. The brass one I bought was only a few $ more, and it was a brand name.

Edit: Here is my post on this topic from a few years back: Water Softener/Filter System: Which One? It's only $32.

Ben Z. wrote:Mine cracked on a seam near a fitting that I never touched - it was a plug of some type IIRC. It was a mfg defect

That's rotten luck. Perhaps more related to the brand of the part (generic, Chinese part?) than it being plastic. I prefer metal parts too, due to the perception that they should have more long term durability. But a brass regulator typically costs twice what a plastic one does. Add that they rarely fail and I don't see that it is a big deal if someone wants to save some money by going with the plastic version. FWIW, I've seen metal parts leak too due to manufacturing defects (miscut threads).

If you're really conservative, go with the brass part and install some kind of water leak detector. Most people don't bother, but the peace of mind is well worth another $50 - $100 to some people. As to the question of lead in some brass parts, I did a one-time test on the water as it goes into my espresso machine to confirm that there wasn't lead in the water. And now I don't worry about it anymore.

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gscace wrote:Discharge pressure in the rotary pumps I have seen is established and tweaked by adjusting the spring pressure against a relief valve plunger that opens up when sufficient force is applied to it. In the pumps that I have had experience with, it's the difference in pressure between inlet pressure and outlet pressure that provides the force to open the plunger, not the pressure with respect to ambient pressure. As an example of how the pump produces 130 psi, imagine that the pump relief valve may be adjusted at the factory to open at 100psi differential between inlet and outlet pressure, with the inlet pressure being at 30 psi with respect to ambient. That makes the outlet pump pressure with respect to ambient equal to 100 plus 30. If you then take the pump and hook it to a water supply with 80 psi pressure, the pressure produced at the pump outlet will be 180 psi with respect to ambient. Since brew pressure is with respect to ambient, you have to consider the inlet pressure and inlet pressure variation when setting up your machine. A good regulator setup controls both, although I can't tell you to what level a single stage regulator controls fluctuations.

This is so very true but it applies to pumps fitted with a standard bypass valve. Most of the pumps in espresso machines are fitted with a balanced bypass valve whose main function is to maintain a reasonably constant discharge pressure with a reasonable variance in inlet conditions. Exactly how well it does this, I do not know.

Not particularly well evidently as I saw group pressure changes on my Vivaldi S1V2 when I played with line pressure & I see the same with the Speedster.

Are you sure your Speedster has a balanced bypass? I remember the pump on yours being different from some of the other Speedsters I've seen on Flickr but I can't recall the bypass type on it. That said, I've not been super-impressed with my experience with balanced bypasses. I've never used a standard bypass (knowingly) to compare it to.

I have a Reneka Techno, plumbed in. The house does have a pressure regulator on it but I don't know the actual output pressure, although for some reason I think it's about 80 lbs. I assume the advice for decreasing the inlet pressure applies to most machines such as the Reneka too?

More to the point, does any one know how machines' pump pressure is set from the factory? E.G. if it is set using an inlet pressure of 30, why wouldn't inlet pressure regulation be part of the installation guide?

. . . but I don't know the actual output pressure, . . .

This would be a good start: https://www.watts.com/pages/_products_d ... sp?pid=646

Attach it to any convenient hose connection and measure during a representative flow condition for YOUR household. An oft recommended value is 50 psi but . . . if you like forceful hot showers at 6 AM, maybe 60 psi . Most espresso machines would like about 35 psi during flow conditions. This would require a small secondary regulator like this: https://www.watts.com/pages/_products_d ... p?pid=3428

Inlet pressure regulation is, in fact, part of some installation guides or affixed to the machine's data plate, but not all.

As others have already stated vibratory pump machines aren't affected too badly by variable inlet pressure.

The rotary pump machines will change grouphead pressure according to the inlet, so if you don't have a whole house regulator get one right next to the machine's inlet. Some say get one even if you do, as Corian countertop cribs are usually also very large (watch out GS3 caffeine barons!) so pressure will vary depending on who is flushing one of the numerous fixtures:)