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Jack_in_VA
Premium Member
join:2007-11-26
North, VA

Jack_in_VA to Ken

Premium Member

to Ken

Re: CSV - real or snake oil?

said by Ken:

Yes I don't have any first hand experience with VFD's. I also don't have any first hand experience with dynamite, but that doesn't mean I'm wrong when I say dynamite is explosive. If you can leave open the possibility that you don't know everything I will be happy to post some links where some engineers and other well qualified people discuss the issue in depth and you will see that VFD's aren't all they're cracked up to be.

With all due respect Ken there's no use in us continuing this since I can see your mind is fixed on VFD's in general being not reliable and troublesome. Let's just move on.

garys_2k
Premium Member
join:2004-05-07
Farmington, MI

garys_2k to Ken

Premium Member

to Ken
said by Ken:

...I will be happy to post some links where some engineers and other well qualified people discuss the issue in depth and you will see that VFD's aren't all they're cracked up to be.

Please do, I'd like to read all sides on this.

My main concern right now is the very high static pressures needed to provide those low flows from pumps designed for much higher flow rates. Not just the pump's thrust bearings, but all of the piping and fittings leading up to the regulator would seem to be placed under pressures well above 150 psi.

I'd love to see if this is really the case, if anyone has put a pressure gauge on the inlet side of the regulator and reported what it reads.

Jack_in_VA
Premium Member
join:2007-11-26
North, VA

Jack_in_VA

Premium Member

said by garys_2k:

I'd love to see if this is really the case, if anyone has put a pressure gauge on the inlet side of the regulator and reported what it reads.

That would be interesting. It would depend on the pump capacity at the time because impellers wear and the pressure capability decreases significantly with wear and the head its pumping against.

I had to lower my pressure setting from 60 psi to 50 as the sand wore my pump to the point it really couldn't achieve 60 psi and would run and run and never cut off. It was installed in 1995.

Ken
MVM
join:2003-06-16
Markle, IN

1 edit

1 recommendation

Ken to garys_2k

MVM

to garys_2k
The guy that invented the CSV goes by valveman on several different sites. Here is one where he talks about the thrust bearings and impeller wear.
»www.terrylove.com/forums ··· e-Valves

Here is a post on valveman's site where they talk about the increased pipe pressures. Basically it's not as bad as you would think. (FYI my well pipe is stamped 450 psi)
»cyclestopvalves.com/smf/ ··· c=1897.0

In this thread a plumber gives his endorsement to the CSV and why he doesn't like VFD's.
»www.ridgidforum.com/foru ··· /t31330/

In this thread some engineer types talk CSV vs VFD.
»www.eng-tips.com/viewthr ··· d=254975

Here some electricians talk about the life expectancy of VFD pumps.
»forums.mikeholt.com/show ··· t=130792

I could go on, but I did a lot of research on the subject. It's safe to say that there are a lot of very knowledgeable people out there who believe VFD pumps aren't that great. There are also a lot of professionals out there installing CSVs over VFDs. In the end there are several topics in play here.

Upfront cost: The VFD is undisputed as costing more
Pumping cost: The electrical usage of a 10gpm VFD and 10gpm CSV pumping @ 5gpm are very similar
Pump cycling: The VFD and CSV both reduce pump cycling a similar amount if you size the pressure tanks correctly.
Long term cost: The VFD would have to last longer than a standard submersible pump with a CSV to come out on top, and yet I find lots of people stating the VFD doesn't last as long, and basically nobody stating the VFD lasts longer.

Jack_in_VA
Premium Member
join:2007-11-26
North, VA

Jack_in_VA to garys_2k

Premium Member

to garys_2k
said by garys_2k:

Please do, I'd like to read all sides on this.

Over my life I've come to regard companies that resort to attack ads on other companies or equipment to promote their products with a great deal of skepticism. This one is glaring. Reading it I couldn't help but snicker as I have knowledge of some of the items they were mis-representing and distorting of facts to favor their product. For that reason alone people should considering using their product with caution.

Variable Speed Pumps (VFD's) are a Scam