On Vibe pumps and OPV's

[Tex]

Alright here is an example....expansion valve.

http://www.chriscoffee.com/products/home/isomacparts/replacementexpansionvalve

That's an OPV - water flows through the two fittings to the right and is diverted through the fitting to the left.

If you want to regulate group pressure without using an OPV (and it's far easier to mount an OPV on your machine & cost ~$50) try regulating the voltage to the pump.

[John F]

That's an OPV - water flows through the two fittings to the right and is diverted through the fitting to the left.
[/quote]

So water flows through the tee on the right and overpressure goes to the left and out of the brass section? Is that right?

I thought that brass section was the adjustment...didn't realize it was a water pathway.

[John F]

Oh, I see it now Tex..you are right. I found a pic on CG of a guy using this valve on an Oscar. He even moved the tee so I'm sure it will work for what I want to do and the matter of flow restriction at the pump isn't important to my mod anymore.

I'm still curious but this OPV solves the need to know. I was driving around thinking about choke shots on non OPV machines and have halfway convinced myself the vibe pump would be ok if somebody used a regulating valve place of an OPV but for under $40 I'm not going to be the one to test it....this valve will be perfect for what I'm planning to do. 

[Tex]

So water flows through the tee on the right and overpressure goes to the left and out of the brass section? Is that right?

I thought that brass section was the adjustment...didn't realize it was a water pathway.

There was a thread on Coffee Geek that dealt with reducing the pump pressure by using resistors. I felt this was more work than it's worth; after all a Gaggia OPV only cost ~$40 and is a simple bolt on replacement for the OEM water inlet.

Replace this


with this

[John F]

Replace this


with this
[/center]

I think that is a very good solution but I'm brainstorming something away from normal. 

[Tex]

I think that is a very good solution but I'm brainstorming something away from normal. 

Somehow, that doesn't surprise me! Just making sure you had the standard mod to fall back on when you did a face plant with whatever you're working on.

Fill us in on your plans and progress as you go along, OK. Anyone who knows me understands that I'm always good for new brain farts!

[yorel23]

Tex,
How do you adjust that OPV?

[bobvilax2000]

Tex,
How do you adjust that OPV?

I'm not Tex, but I'll have a go at being him.

You just turn the smallest threaded hex to the left of the image. It's a very good opv.

- -Barrett

[yorel23]

Thanks.  Any links to the best place to buy these?

Sorry John.  Not trying to hijack your thread.

[Tex]

Tex,
How do you adjust that OPV?

The Parts Guru has them. Pick up a couple extra group gaskets with your order - you'll need them & they won't add anything to the shipping weight. Hint: Call you order in and insist that they sell the gaskets w/o the extra stuff they package with it.

Remove the hose on top & the hex fitting (don't lose the o-ring under it). There's a #4 Phillips fitting inside - clockwise = more pressure.