Flygt VS ShinMaywa sump pumps 2

[USAeng]

Looking at 4" submersible pumps for a sump station - 2 quotes so far

1st has Flygt model 3102.185-0289 5HP

2nd has ShinMaywa model 4CNWX45.5T3E-55.2 10HP

Quote for ShinMaywa is cheaper but don't want to go with them unless they are equivalent to the Flygt

Does anyone have any experience with these 2 brands?

 

[Pumpsonly]

One is using 5 HP and the other is using 10HP yet is cheaper.
If both are rated for the same flow and head. The 10HP pump is definitely very much lower in efficiency and build quality.

 

[USAeng]

Flowrate is better on the 10HP
was hoping just to get overall experience with the brands - I will be finalizing the pump sizes later

 

[fel3]

I used that exact same Flygt pump in the NP configuration for a small sewer lift station I designed about 5 years ago and I have used other Flygt models over the years. I have not used the other brand at all (I hadn't even heard of ShinMaywa until about six months ago).

IMHO, Flygt is in the upper tier for quality, which means they also cost a bit more. Some of my municipal clients prefer single vane impellers for sewer service (much lower clogging potential) and Flygt is one of the few brands that offers single vane impellers. When I design sewer lift stations, the first brand I look at is Flygt and often it's the only brand I look at due to client preference.

Back in the mid-1990s, I got involved in construction support for the new headworks building at the Fresno-Clovis Regional Water Reclamation Facility. The lift station in the headworks consists of six Flygt pumps with space for two more. At the time (my project manager told me), these were the largest dry-pit submersible pumps in the world (two at 22,500 gpm/32.4 MGD/435 hp and four at 32,000 gpm/46.1 MGD/575 hp). Attached is a photo showing most of the pumps.

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"Is it the only lesson of history that mankind is unteachable?"
--Winston S. Churchill

 

[USAeng]

Thank you for sharing your experience! I really appreciate it

 

[Slagathor]

fel3,

Flygt no longer uses this installation as a marketing tool due to repeated failures. In fact...you see pump #2 is down in your picture. These large closed loop dry pit motors kept failing (too much heat to reject I believe), and the WWTP plant staff became frustrated with the long and costly repairs. I am sure Flygt has a different perspective, but if you look down the line, you will see a conventional bearing frame vertical non clog pump in location number 6. Fresno hired Carollo Engineers to design an upgrade to put in a conventional non-clog to improve reliability. That pump (a Fairbanks Morse 30" 5700 series I believe) was installed around 2006...and is now the staffs preferred pump to run, as it has proven most reliable. Flygt is a market leader, and makes some great pumps, but they do not do everything right. This project ended up being a black eye for them. I do not believe they are now marketing dry pit sub motor this large, due the heat rejection challenges.

By the way...when you get to pumps that large...pretty much anything is a "non-clog"

 

[fel3]

Slagathor…

Thanks for the update. I joined HDR about the time construction started and left about the time construction was completed. What I knew about the design came from the PM and design team. I didn't even know such pumps existed until then. . The only pumps approaching that size that I had worked with before then was a couple of 26.5 cfs low-head pumps I had selected for a storm drainage lift station (Fairbanks Morse vertical turbine solids handling pumps). Most of my pump designs have been <100 hp.

I took that photo during an ASCE field trip last year, but we didn't get into the pump pit due to the maintenance activities. I noticed the pump change, but the guy giving the tour got sidetracked and never got around to answering my question about it.

You may be interested in the following issue I had to deal with regarding these pumps when flow was first switched over to the new headworks. Operations staff noticed immediately that around certain flow rates (including around peak flow), the pumps -- all variable speed -- kept turning on and off trying to match the inflow and work with the set-points in the wetwell. As I investigated, I learned that the pump submittal had been accepted with the small pumps having tested almost exactly on the published pump curve, but the large pumps having significantly better performance than the published curve. What this meant was that there were several gaps in available pumping capacity between minimum flow and peak flow. Nobody had bothered to figure out what effect the higher performance large pumps would have on operation. I probably still have a copy of the simple spreadsheet I built to figure it out.

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"Is it the only lesson of history that mankind is unteachable?"
--Winston S. Churchill

 

[bimr]

You probably will not find that much difference in that size of a pump.

What may be more important is the after sale service capabilities of the supplier. You would be better off if a stocking distributor is local than miles away.