Kaixin Pumps

[Wolfy]

In another thread, I promised a review of these when they arrived ... so here it is.

The sticker and website says they're made by Wenzhou Kaixin Pumps Co. Ltd, and the brochure I got calls them "Kaixin" so that's a much better name than " Chinese 240v Food Grade Magnetic Drive Pump".

There are a number of similar looking pumps on Alibaba, sold on Ebay and in LHBS, and to confuse matters more it appears that many are OEM/rebranded. After several weeks worth of emails (to various vendors) I purchased some pumps for a Bulk Buy on the AHB forums from Wenzhou Kaixin via their Alexpress Store. Once the order was placed and paid for, the pumps arrived at my doorstep (shipped via DHL) within a week:


The website currently lists the MP-15RM at US$28.58 which makes them comparable in price to the little brown solar pumps.
Shipping (to Australia) is US$30-40 for individual orders, but bulk-buy or shared shipping should reduce the shipping costs to somewhere around US$15-20 each.

The MP-15RM pump that I ordered for myself looks like this:

The brochure and website all show yellow-body pumps, since I wanted a pump with 1/2 inch threaded fittings the older stock green-body pumps were supplied, the new ones say they have 3/4 inch fittings.

The Kaixin pump's housing and impeller is made from is 'food grade' polypropylene, however the manufacturer does not rate them for use for pumping water at 100degC, instead suggesting they should only be used up to 80degC.

Specification sticker on the MP-15RM:


After unscrewing the 6 bolts on the front:


.. and removing the impeller/housing:


Since they are actual magnetic drive pumps, they should be much easier to clean and maintain than the little brown solar pump, which I've found tends to get grunge around the impeller shaft and then stops working.

Setup and ready to go:

The thread on the intake port was quite 'tight' (slightly oversized) for the US-supplied camlock fitting so it required some force to get it on more than a couple of turns (which might not be a good thing with a plastic pump housing).

I had already started brewing (with the little brown solar pump) when the Kaixin pumps arrived today, but had one wired up in time for cleaning up:
Here is the flow rate from the ground to the top of my keggle (approx 1m): http://www.youtube.com/watch?v=Yxs4DHj_fwU

Compared to the little brown solar pump: http://www.youtube.com/watch?v=ooNDkBXg0y0

From the bottom of my brewstand to the top of the HLT (approx 1.5m): http://www.youtube.com/watch?v=qO26_UDAB8Q

The pumps are very well priced, appear to be well made and seem to work well (so far). Time will tell how they work and last when pumping wort and how they go (or if, or or how long they work for) when operating with boiling wort/water.

[Kev888]

Most interesting - thanks for posting! You certainly seem to get a lot of pump for the money; still nice and quiet too even though much bigger than the solar ones. I'll be very interested to hear how they turn out.

Cheers
Kev

[Fil]

cheers wolfy hope the boil tests work out ok too..

[pete57]

I just ordered mine delivery costs more than the pump to the uk. However with the combined cost of just £41.07 (USD 66.61 its worth a try . March May wanted £160 with delivery so this is a quarter of the price. Thanks for the lead. Owe you a pint.lol

[barneey]

+1 to hoping the test work out ok

[Wolfy]

Used the pump again today while cleaning the brewery.
It operates quietly, continuously and without problem at temperatures up to and including mash-temperatures.
However, when recirculating cleaning solution at 'rolling boil' temperature, within a few minutes the flow was slowed, eventually to a trickle (when I turned off the pump so it would not be damaged). A short time later the pump worked at full flow, but slowed again. After the cleaning solution was left to cool for a short while (to about 90C) the pump appeared to work without issue at the full (or close to it) flow rate.

From this experiment, I'd conclude the following:
The Kaixin pump should work fine for a HERMS/RIMS setup, transferring strike water into the mash and wort out of the mash to the kettle, it should be OK to drain the kettle after it as cooled a little (~90degC).
It might work with an immersion chiller to whirlpool immediately after the boil, but I don't have an immersion chiller to test this.
I don't think it would work (for long enough) to drain the kettle, immediately after boiling, if it's installed on the hot-side of plate or counter flow chiller.

[Kev888]

Oh dear, a pity that; I guess it was asking a lot to take it to boiling but you can always hope!

I still think this sounds like a pretty decent pump and top value for money though; should do most things if you sanitise it chemically. I hope it runs well over time/use!

Cheers
Kev

[Wolfy]

There was mention on the AHB forums that some March pumps used to/do the same and the 'fix' was to shave just a small amount off the impeller, but I might see if someone else wants to try that first.

[barneey]

There was mention on the AHB forums that some March pumps used to/do the same and the 'fix' was to shave just a small amount off the impeller, but I might see if someone else wants to try that first.

Mmmm mount impeller into drill, advance impeller to abrasive material, a light touch + test to see what happens with boiling liquids + test to see what happens to the flow rate + test to see if the noise increases etc.

Go on Wolfy be the first

[stevetk189]

Intredasting thread. I've been ummming and ahhhhhing over pumps for months and have been steering towards the solar pumps but they seem so tiny and fragile. These blighters look a lot more robust and easier to whip apart for a clean up. Nice find.

[Wolfy]

If you don't need to pump boiling wort, these seem like an ideal and cost-effective solution (but it's hard to be sure until it's been used for year(s)). The biggest issue I had with the little brown solar pumps (other than one breaking quickly/easily) is that they are hard to clean and the wort gets in around the impeller shaft.

Interestingly after more emails with the manufacturer (and his factory-engineer) it might be possible for them to make new pumps (with a different housing material) that work when pumping stuff at 100degC, which would (at this preliminary stage) involve only a small cost-increase. However, to make building something specific for home-brewers he'd need an initial order for hundreds of pumps, so I gave his details to an Australian import/distributor who was interested, so it may happen in the (near) future.

[weiht]

Its more powerful than the little brown bugger, but I wish it could take hot wort as I need the added power to serve up a good whirlpool. How do u sanitise the pump? I usually run the pump at last 15 mins boil, so the hot wort shld sanitise the pump and the silicon tubes.

The little brown pump hasnt failed me, and never shuts down even when boiling wort is running for 15-20 mins. However, I got some foaming over the last 2 brews after running it for 10 mins. Any idea why?

[Highlander]

This looks good. If my solar pumps give up the ghost I might give it a try.
Hopeing someone will try triming the rotor soon and see how it goes.

[weiht]

what does trimming the propeller do?

[weiht]

Emailed the company and they said they are in the midst of building a pump for an aussie company that can take 100-120c temperature. They are not testing the pump and if everything is ok then they will start producing from 20th next mth

So hold ur horses!!

I have registered my interest to him, and will update here when its available

cheers