Kaixin Pumps

[Wolfy]

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 the pumps for the Bulk Buy 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 is $30-40 for individual orders, but bulk-buy or shared shipping should reduce the shipping costs to somewhere around $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):

Compared to the little brown solar pump:

From the bottom of my brewstand to the top of the HLT (approx 1.5m):

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.

 

[Wolfman]

Nice work on the Bulk buy Wolfy.

 

[sp0rk]

i should keep an eye out on the bulk buy section more often

 

[Wolfy]

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.

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.

 

[mika]

Same problem has existed at various times with the March Pump. Impeller can swell with the high temps and jam in the housing, some have had to trim the impeller to alleviate the issue. Could be the same problem here.

 

[Wolfy]

Same problem has existed at various times with the March Pump. Impeller can swell with the high temps and jam in the housing, some have had to trim the impeller to alleviate the issue. Could be the same problem here.

I suspect it could be something similar, but might let someone else do the 'testing' on this one.

 

[glenwal]

"Kaixin" so that's a much better name than " Chinese 240v Food Grade Magnetic Drive Pump".

Haha, nice


Well done on the bulk buy Wolfy. They look like a pretty sweet pump, and the price is definitely right.

 

[Wolfy]

Haha, nice

Thought that would make you happy.

 

[Wolfy]

Since I was such a friendly customer the manufacturer asked if I'd like to import the pumps into Australia.
I suggested that they'd need to be able to work at 100degC without issue for long periods if they were going to be 'ideal' for home brewing. A few more emails later, discussion with his factory-engineer and it seems it will be possible. Since it will involve new materials for the housing (maybe polysulfone or fiber-reinforced polypropylene) and retooling/new materials, he'd want an order in the 100's to make it worth while. Bulk-buys can't cater for such a situation, but I gave the details to a someone who might be able to make it possible, so it's possible that in the near future, we might see the new pumps in the Australian market.

 

[Online Brewing Supplies]

I feel we will see many new pumps in the near future.
I have a new Mag one coming which is stainless and brass.
No issues with heat or food grade.
Made in the EU.
Nev

 

[Franko]

I feel we will see many new pumps in the near future.
I have a new Mag one coming which is stainless and brass.
No issues with heat or food grade.
Made in the EU.
Nev

Looking forward to seeing that new one Nev

Franko

 

[keifer33]

I feel we will see many new pumps in the near future.
I have a new Mag one coming which is stainless and brass.
No issues with heat or food grade.
Made in the EU.
Nev

Let us know when it arrives Nev will be all over that.

 

[Online Brewing Supplies]

Sure but I didnt mean to hijack wolfy,s thread so I will start a new one when the pumps are finished trials.
Nev

 

[keifer33]

Indeed hard to ignore new pumps. Sorry Wolfy for derailing.

 

[Wolfy]

First actual brew with the Kaixin pump today and the pumps worked without problem.

The only issue I had was a compacted grain bed due to a fine grain-crush and running the pump too quickly, adding some rice hulls and not opening the valve (on the pump outlet) too quickly resolved those issues.

Pump ran fine for the 2 hour recirculated mash

... then another 30mins (with the valve very restricted) while fly sparging

At the end of the boil, the pump recirculated almost-boiling (95degC) water through the plate chiller for about 10 mins and then was used (on the hot-side) to pump out of the kettle and through the plate chiller.

Flow through the plate chiller was significantly faster than the little brown solar pump or gravity, so much so that even with the cold-tap water running flat out (something I've never had to do before), the 30-plate plate chiller couldn't quite keep up. Into the fermentor the wort was about 21.5degC when it's usually under 20 this time of year, so next time I'll throttle the flow back a bit.
But I was happily surprised that the pump worked without issue on the hot-side of the plate chiller for long enough to drain the kettle (directly from boiling).

 

[QldKev]

Been watching these pumps for a while. They look like they are performing and as you mentioned, it looks like a decent middle ground between the brown pump and the march. :beerbang:

I think the extra flow over the brown pump would help with equalizing the temps in the mash tun when using external heat exchangers and ramping. If I hadn't already got a brown (well actually white) pump for my one-off's system I would have gone this way. If/when the brown pump dies I think I will upgrade to a Kaixin pump.

QldKev

 

[stillscottish]

Would the extra flow-rate matter?
Surely the ideal flow-rate you want is the maximum your manifold/false bottom/whatever can handle without compacting and that will be independant of the pump's capacity.

Cheers

Campbell

 

[QldKev]

Would the extra flow-rate matter?
Surely the ideal flow-rate you want is the maximum your manifold/false bottom/whatever can handle without compacting and that will be independant of the pump's capacity.

Cheers

Campbell

But what if the maximum your manifold/false bottom/whatever can handle without compacting exceeds the brown pumps capacity? Then wouldn't you be better off with a stronger pump to ensure when ramping you get the turnover to help the wort in the mash bed be at the same temp as per the return line from the heat exchanger?


QldKev

 

[stillscottish]

My brown pump sucks better than........ (insert favourite euphemism here) :lol:

Seriously, it does. I have to throttle it well back and I'm using 1 metre ss braid under a false bottom.

 

[QldKev]

Review of a Kaixin MP-20R

I purchased a Kaixin MP-20R from the link supplied by Wolfy.

Background
I've been running a march 809 on my main 3V for a while and have been happy with it. When it came time to build a smaller testing system to allow me to run single sized batches for test recipes and beers like weizens and a lambic where I don't want multiple cubes full, I wanted something to run it without the need to remove the march from the main system and risk damaging it. After trying a brown pump, which I proceeded to break during mounting (my fault as I could see how thin the housing was), then gluing it back together to find it didn't flow to my requirements for THIS system, I proceeded to order a kaixin pump.

Delivery Time
Ordered Sun 7th arrived Tue 16th.

Un-packaging
Looks like as per Woly's pic, but mine is slightly larger and is white. Same box arrangement.

Wiring
This morning I got up and put a plug on it. The cable is thin, which is acceptable as the motor draws bugger all current. The plug I purchased is suitable all the way down to 2 core 1mm2 (the motors cable is 3core) The cable lock will not screw down far enough onto it to grip, so if you wire one up you need to think about this.

Sizing
I went the MP-20R for the higher flow for my 'testing brewery' as I wanted to redirect a lot of the flow back at the internal heating element to ensure wort movement at all times. Also I didn't go the threaded option as I snapped the brown pump the first time I tried to bolt parts to it. Being 18mm inlet and outlet I was concerned if the 1/2" silicone hose would fit, It went on easy.

Priming
I placed the pump under the brew vessel, and hooked up the hoses. I opened all valves to bleed the system of air, and left it for a couple of secs once the bubbles stopped (as I do with the march pump). When I fired up the pump I had no flow, so I shut it down immediately. As soon as I turned it off more bubbles started. Upon firing it back up I had some flow but the pump was cavitating, so I shut it down a second time, more bubbles. Next time it fired up no problems and I had decent flow. Stopping and restarting the system, but keeping it full of water, I had no issues. I've never had the same issues with the march, but will just keep an eye on it. Also to be fair this is a different system against where the march pump is running, but I have got similar placing of the pump.

Noise
I think this pump is quieter than the march 809. Maybe next brew I should put the db meter against them. Both are quite enough for me.

Performance
This pump is rated at Max flow 27L/min (same as march 809) and Standard flow @ 3.1m 17L/min (march 9.5L/min).
The system it is running on, has a head of 0.75m. That is 0.75m from the outlet of the pump to the upper return line.
The inlet and outlet are spec'd at 18mm, I am only using 1/2" plumbing on my system so it will impede the flow.
Tested on my system I'm achieving 14L/min. On the same setup I got 4.5L/min from the 12v brown pump.

Comparison to march 809
The march 809 seems to have more flow once loaded up a bit in the real world. Next time I run the march pump I will try and remember to get a flow measurement from it.
The march has a polysulfone head and is rated to 121c
The kaixin has a polypropylene head and is rated to 80c

The march cost about $200 (inc post)
The kaixin cost $84 (inc post)


Overall
It's been running for the last 1hr straight, no problems.
I don't recirculate the kettle, so the extra temperature rating of the march is not a huge concern but is a nice buffer to have.
I think the kaixin is a great pump for the money, and hopefully will prove to be as reliable as the march pumps have been.

It will be interesting to see what the higher temperature rated ones will cost when they hit the market.


QldKev