ECM Technika IV Direct Plumbed... Pressure gauge reading 4.5 BAR

#1: Post by **M Diddy** » July 17th, 2013, 1:06 pm

Gents,

Just installed the under-sink water softening, filtration system from Chris's Coffee and ran a 3/8's line directly to my ECM Technika IV. Made the necessary setting on the machine (turned the valve underneath and moved the front switch to direct connect). No leaks anywhere in the system. All good the whole way through.

Turned on my machine, and noticed that right off the bat, the group pressure gauge is reading 4 - 4.5 BAR without me running the pump or the boiler filling. Just turned it on, that's all. Is this normal? Should it be reading this high sitting at idle?

If I life the lever, the pressure climbs up to 9.5-10 BAR, which appears to be where it should, but the positive reading at idle worries me. Anything I should look at or do?

Thanks for the help!

#2: Post by **pechelman** » July 17th, 2013, 1:21 pm

sometimes those e61 groups can idle at high pressures
we have an expobar IV-R here at work that sometimes idles with a group pressure reading at 12bar even despite it being "plumbed" from a water jug.

what you need to do is add in a pressure regulator after the filter but right before the machine and regulate pressure to the manf's recommended level. (usually in the ~30-40psi range)

like this; http://www.chriscoffee.com/Pressure_Reg ... 34g-38.htm

#3: Post by HB » July 17th, 2013, 1:37 pm

It's normal.

Presumably the 4.5 bar reading is the mains line pressure (around 65 PSI, which is a little on the high side). Assuming you have a backflow preventor, the brew pressure gauge will shows the pressure of a closed system, which means it may go higher than 4.5 bar as the water heats. I elaborated on this point in another post:

HB wrote:The pressure reading when the machine is idle isn't important.

To elaborate, pulling a shot introduces cooler water into a closed system, but then you suddenly close off the main exit at the end of the extraction. As the water in the boiler warms up, it expands and the pressure rises. The expansion valve is typically set to open around 12 bar for rotary pump espresso machines since they have their own bypass valve to regulate brew pressure. For vibratory pump espresso machines, the expansion valve (traditionally called an over-pressure valve in this context) is set to open at the desired maximum brew pressure, usually around 9 bar. This valve vents water into the driptray to avoid subjecting the hydraulic system to excessive pressure. It only needs to let a few drops of water escape to reduce the pressure sufficiently.

There's no need to worry about the gauge reading when the machine is idle as long as the reading is < 12 bar. For reference, below is a reminder on how to adjust the brew pressure of a rotary pump.

HB wrote:You should find a pressure adjusting screw similar to the one shown below:

From Procon exploded view; also see Adjusting espresso machine's rotary pump brew pressure?

Counter-clockwise = more water passes from outlet to inlet through the bypass valve = lower pressure. Clockwise = less water passes from outlet to inlet = higher pressure. The adjustment is fairly sensitive, i.e., one-half turn should produce an immediate increase in pressure. If not, the relief valve could be stuck; it's also possible there's an obstruction along the way to the brewhead (e.g., the gicleur could be clogged with scale). To confirm or eliminate the pump as the cause of the problem, tee in a pressure gauge immediate after the pump. It will show the pump's output directly.

July 17th, 2013, 5:20 pm

pechelman wrote:sometimes those e61 groups can idle at high pressures
we have an expobar IV-R here at work that sometimes idles with a group pressure reading at 12bar even despite it being "plumbed" from a water jug.

what you need to do is add in a pressure regulator after the filter but right before the machine and regulate pressure to the manf's recommended level. (usually in the ~30-40psi range)

like this; http://www.chriscoffee.com/Pressure_Reg ... 34g-38.htm

I actually did some Goog'ling and found that adapter after I posted my question. Put in an order for it and should have it tomorrow. Thanks for the tip!

July 17th, 2013, 5:27 pm

HB wrote:There's no need to worry about the gauge reading when the machine is idle as long as the reading is < 12 bar. For reference, below is a reminder on how to adjust the brew pressure of a rotary pump.

Dan, thanks for the reply. If I'm reading your post correctly, you're simply stating that, since the OPV on the rotary pump is set to around 12 BAR, having any pressure less than that 12 BAR is OK, as you're below the point that sets the OPV off. Correct?

The thing that worries me, though, is that, under normal, tank conditions, the machine will sit at 0 BAR, and only raise when the lever is thrown and the pump is turned on. While plumbed, now, the machine is sitting at 4.5 BAR, roughly 65 PSI, at all times. I would think placing the internals of the machine, at that high a pressure, at all times, can't be good for the insides in the long run. Am I wrong in my thinking?

#6: Post by HB » July 17th, 2013, 5:43 pm

M Diddy wrote:...you're simply stating that, since the OPV on the rotary pump is set to around 12 BAR, having any pressure less than that 12 BAR is OK, as you're below the point that sets the OPV off. Correct?

Correct.

M Diddy wrote:I would think placing the internals of the machine, at that high a pressure, at all times, can't be good for the insides in the long run. Am I wrong in my thinking?

Yes, you are wrong in your thinking.

Consider this: The plumbing in your house is continually subjected to similar pressure. Your house has an expansion tank, usually located near the water heater, that prevents the pressure from rising too high if the water in the pipes heats up. Similarly, your espresso machine has an expansion valve (also called an OPV) that lets a few drops of water escape to the driptray if the pressure is too high.

July 17th, 2013, 6:01 pm

HB wrote:Yes, you are wrong in your thinking.

Consider this: The plumbing in your house is continually subjected to similar pressure. Your house has an expansion tank, usually located near the water heater, that prevents the pressure from rising too high if the water in the pipes heats up. Similarly, your espresso machine has an expansion valve (also called an OPV) that lets a few drops of water escape to the driptray if the pressure is too high.

Understood. Thanks for the info.

Since I've already placed the order for the pressure regulator from Chris's, I'll be installing it in-line, before the ECM, just to be safe, but it's good to know that as the machine sits right now, I won't be causing any damage.

I also spoke with Jim at 1st-Line today (of who I can't speak highly enough) and he also recommended installing the regulator to bring the pressure down to around 40 PSI per ECM's recommendations. It can't really hurt either way.

As always, thanks much for the help gents. Always enjoy gaining a bit more knowledge coming on to here.