How to manage 2 groups, 1 external pump?

#1: Post by **wearashirt** » August 14th, 2015, 9:53 am

Hi guys!

I'd like to know how different machines program the rotary pump for 2 groups. What are the options and techniques for using 2 groups kiosk settings?

In a forum, I read that Linea groups have to be actuated simultaneously, so the pump would compensate and produce the same 9 bars.

Hopefully you can give some insights from VBM, LM, NS, KVDW..

Thanks!

#2: Post by **HoldTheOnions** » August 14th, 2015, 8:55 pm

I've wondered the same thing myself.

#3: Post by **ira** » August 15th, 2015, 12:33 am

I believe that the average rotary pump is capable of supplying much more volume than is need by 2 or maybe even 10 groups so that is not a problem. Look at the flow rating on the pump and you'll see what I'm talking about.

Ira

August 15th, 2015, 5:50 am

Ira, that's really good to know. I wonder if it's electrically reprogrammable.

Right now, my NS Appia II Compact does not want simultaneous shots! There seems to be some programmed pressure compensation when two groups are staggered, but doesn't look too reliable. When actuated simultaneously, 6 bar is the final pressure. Sux!

http://users.rcn.com/erics/ · #5: Post by **erics** » August 15th, 2015, 9:43 am

When actuated simultaneously, 6 bar is the final pressure.

Then, something is amiss with your water delivery system whether that be the pump itself, the connecting lines, the filtration network, etc., etc.

Post some pics of your "system" including the make and model of the pump.

August 15th, 2015, 3:55 pm

Agree pump should be more than capable of proper final pressure. Even a 4 group Linea (single pump) no problem.

August 21st, 2015, 12:50 am

erics wrote:Post some pics of your "system" including the make and model of the pump.

Here's photos of the internal system.

Image 1a-c. Fluid-o-tech pump. Water enters through the silver inlet pipe, exits through white plastic tube

Image 2a-b. Group 1, pre-boiler. White plastic tube enters copper tube and into a diversion for the two groups, then proceeds to the boiler.

Image 3. Group 2, pre-boiler and drainage.

Image 4. The boiler from the top.

#8: Post by **boost** » August 21st, 2015, 9:44 am

The vanes on the rotary pump can wear, especially if ran dry. Fortunately if you are handy you an buy replacement vanes from fluid o tech for less than $10.
If not then you can buy new pump head too.

August 21st, 2015, 9:55 am

Can I also get some commentary on the (pure) copper boilers? They don't appear too shiny and smooth to my eyes...

August 21st, 2015, 10:07 am

I understand the pump can deliver enough pressure, just wondering how it is regulated. So you open grouphead and pressure has to build. If you opened a second grouphead then thinking pressure would drop temporarily on both groupheads until pressure builds again. Thinking it must be regulated somehow. Or not.