March AC-3B-MD Pump

[TopherM]

I just picked up this pump. It has an 3/4" FPT inlet and a 3/4" MPT outlet. After a quick look at Bargain Fittings and Brewer's Hardware, it looks like 3/4" is not a standard fitting size, at least not in the brewing world.

Does anyone else use this pump or others with 3/4" inlets/outlets? Any issues with using a coupling to reduce the size to 1/2" to match everything I already have, or is that a detriment to the flow? Can anyone recommend the fittings you use? I wanted to go with camlocks, but again, nothing in 3/4" on any of the major brewing hardware sites, and 3/4" SS camlocks on the industrial sites are wicked expensive!! Do I convert to 1/2" or keep the whole system at 3/4"?

I'm putting together a BIAB stand with wort recirculation (probably just during mashout) and recirculated cooling through my plate chiller, and would like to make it CIP as much as possible. Thanks for the suggestions!!

 

[TopherM]

This is what I was most concerned with from the March installation page. This would seem to suggest that reducing everything to 1/2" would be detrimental to performance. However, doesn't everyone in the brewing world use 1/2" fittings?

3. Suction piping should not be smaller than the pump suction size and preferably one size larger than pump suction. Liquid supply vessel should not have a pipe size smaller than the pump suction and then increased to pump suction size.

 

[LuiInIdaho]

As far as the output side goes, I can't see any problems with reducing things to the 1/2 in size. This is equivalent to throttling down the output side of the regular pump with a ball valve. I am not so sure about the input side. If at all possible, I would try to keep the input side at 3/4 inch. As far as volume goes, there the 1/2 size will handle a little less than half the volume of the 3/4 size in a given time frame.
I hope that this helps. Mark

 

[Protto]

I have a March TE-5S-MD pump that I got of ebay as an air driven unit (AM version). I replaced the airmotor with a 250w 3-phase industrial electric motor. Fitted a Minarik variable frequency drive to get the most RPM's out of the motor as possible.
The pump has 1" Female NPT threads and I use 1/2" silicone hoses and Morebeer's QD's in my brewery, so I fitted a reduser to the inlet to see if 1/2" was sufficient.
On full throttle, about 4200-4300RPM's on the pump it will suck the silicone hose flat, but up to about 4k everything is OK as long as I don't get kinks in the suction hose.
The magnet will decouple at speeds around 4300-4400 anyway.

If you meashure ID of your 1/2" NPT fittings you will find they are a lot larger than actual 1/2". It it the hose that will be the botleneck.

If you want cam-lock: http://store.proflowdynamics.com/modules/store/Stainless-Steel-Camlock-Fittings_C68.cfm all sizes, prizes are not to bad either. You might be able to find 3/4 or 1" silicone hose on ebay if you decide to go that route.

Picture of my modifyed pump attached.

 

[stevehaun]

The pump will work best if not restricted on the return end. You can restrict the output end all you want.

 

[JRems]

I think it will be fine. I'm using a little giant pump with a 3/4" inlet. I reduced to 1/2" and don't have any issues.

 

[TopherM]

Thanks everyone! I just spoke with a March engineer, and he told me pretty much the same thing you did - keep the inlet side at 3/4", but 1/2" on the outlet side is fine.

Prost!

 

[WalterAtMarchPump]

If you spoke with someone today then it was either Hans or Otto....I have been breaking in the new guy in the service dept.
Anyway as far as the 3B goes...if you are limited to 1/2 line in your system....you can use it as is and adapt as needed....but keep in mind you WILL need to choke the outlet just a tad to balance out the flow through the pump. Here's a brief explanation why:

The pump as it comes right out of the box, is designed to have a 3/4" line feeding it and a 1/2" line on the outlet side....if you go smaller on the inlet, you are limiting how much fluid can enter the pump. The pump will still continue to try and give you the output its rated to do...but there is not enough liquid coming into it to do that because of the smaller inlet size. So what happens in a mag drive pump is that the impeller will get sucked forward as it tries to suck liquid into itself and it will start to ride up against the thrust washer, eventually wearing the impeller bushing area out, and the impeller will start to hit the front cover and you will get de-coupling issues.

So if you are limited by 1/2 line in your system i would install a valve on the OUTLET side and choke it down to about 6 or 7 gpm max instead of the rated 10gpm that it can do....hope that helps

 

[TopherM]

Yep, I talked to Hans. Thanks for the explination!

 

[imperialipa]

I am looking at the AC 5B pump and my situation is the opposite. All my hoses are 1" and the inlet on that pump is 1" but the outlet is 1/2"... So I need to increase the outlet from 1/2 to 1" as opposed to restricting the outlet.

Any problems associated with that? Cavitation? Oxygenation of wort? Reduction in GPM?

I plan on attaching a Tri clamp Concentric reducer that will take it from 1/2 to 1"

https://www.brewershardware.com/Tri-Clover-Clamp-Style-Concentric-Reducer-1-X-1-2.html
https://www.brewershardware.com/1-2-Tri-Clover-X-1-2-FPT-TC05F12.html

 

[mattd2]

I have a March TE-5S-MD pump that I got of ebay as an air driven unit (AM version). I replaced the airmotor with a 250w 3-phase industrial electric motor. Fitted a Minarik variable frequency drive to get the most RPM's out of the motor as possible.
The pump has 1" Female NPT threads and I use 1/2" silicone hoses and Morebeer's QD's in my brewery, so I fitted a reduser to the inlet to see if 1/2" was sufficient.
On full throttle, about 4200-4300RPM's on the pump it will suck the silicone hose flat, but up to about 4k everything is OK as long as I don't get kinks in the suction hose.
The magnet will decouple at speeds around 4300-4400 anyway.

If you meashure ID of your 1/2" NPT fittings you will find they are a lot larger than actual 1/2". It it the hose that will be the botleneck.

If you want cam-lock: http://store.proflowdynamics.com/modules/store/Stainless-Steel-Camlock-Fittings_C68.cfm all sizes, prizes are not to bad either. You might be able to find 3/4 or 1" silicone hose on ebay if you decide to go that route.

Picture of my modifyed pump attached.

One quick question, why do you have a ball valve on your pump set up with a VSD?

 

[WalterAtMarchPump]

I am looking at the AC 5B pump and my situation is the opposite. All my hoses are 1" and the inlet on that pump is 1" but the outlet is 1/2"... So I need to increase the outlet from 1/2 to 1" as opposed to restricting the outlet.

Any problems associated with that? Cavitation? Oxygenation of wort? Reduction in GPM?

I plan on attaching a Tri clamp Concentric reducer that will take it from 1/2 to 1"

https://www.brewershardware.com/Tri-Clover-Clamp-Style-Concentric-Reducer-1-X-1-2.html
https://www.brewershardware.com/1-2-Tri-Clover-X-1-2-FPT-TC05F12.html

First thing i would do is measure the ID of that 1/2" fpt adapter and see what it is....if its 7/16" or less then it will act as an orifice and you shouldn't have any problems....if its bigger and is a true 1/2" ID then you "could" potentially run into de-coupling issues or wear out the front bushing area of the impeller.
When you have a bigger pipe on the outlet of the pump, then what the outlet is setup for, the pump can try and push out more liquid then what is coming into it depending on the level above the pump feeding it. You really need to look at all the factors of the setup: how big a head height the pump is working against, how long the runs of tubing are, any elbows/fittings/valves in the system, how high is the supply tank above the pump, what kind of gpm you are looking to get out of the pump, etc. What we normally instruct customers to do is, if they can fit it into their system, we recommend about 36" of outlet pipe size before stepping up to a bigger size pipe. If you can't fit that in your system then what you can do is first run a batch of water through the pump and measure what its output is. Not knowing how big a system you have, i will assume since you have the 5B pump its a good 20 gallons or more......so since this pump can do 17gpm i would fill the tank you would be using to transfer the beer into with 17 gallons of water and mark it on the inside of the tank with some tape or something... drain it or transfer it into your main tank and then top off your main tank full and time how long it takes to fill your marked tank back up to 17 gallons.....if you are under a minute then i would install a valve on the outlet side and choke the pump down till you are right at the 17gpm....if it takes longer, then you have nothing to worry about and you should have no problems at all.

Hope that helps....if i confused you in any way then give me a call here at March

 

[ScubaSteve]

If you need 3/4" fittings, check buyfittingsonline.com and for camlocks you can check proflowdynamics.com

If you're restricting the pump by way of plumbing, then you might as well sell it and buy a smaller series 2 pump. The series 3 pumps are impressive in a home system, especially for whirlpooling and transfers, but they're not really needed unless you're doing large batches.