UPDATE: SHURflo Macerator Pumps 3200 series

[Ron]

I have received information regarding the SHURflo 3200 series which are installed in the RoadTreks that it is listed as self priming, but in the RoadTreks system it is at the same level or lower then the tank which in effect gives it a gravity feed.

From the Black/Gray holding tanks to the Inlet of the Macerator Pump, head pressure would force the liquid and solids to the Inlet of the Macerator Pump.

As soon as the valve is opened between the black or gray tank, product runs to the pump until it is turned on at which time it is ground up and disposed of.

As said above the SHURflo Macerator Pump is a self priming pump, but does not suck the liquids and solids into the inlet of the Macerator Pump. As many folks are under the impression that it sucks the liquids and solids into the Macerator Pump, it does not.

The SHURflo Macerator Pump installed by RoadTrek is a good pump, although myself I still prefer the gravity feed sewer hose.

Ron,

[markopolo]

By definition, self-priming means that it will create suction to get the waste to the pump.

The pump section is self priming, permitting the unit to be mounted above the tank in a convenient location.

The above quote is from Jabsco a SHURflo competitor.

And this quote:

The pump is a self-priming pump so does not need gravity feed, but for optimum performance and life, it should be mounted as close to the tank as possible.

Is from the SHURflo rep email I was copied in on.

From experience, I know macerator pumps create suction. I watched my sewer hose rapidly shrink when I closed the valve before turning off the pump. (portable macerator)

I'm not suggesting that the mounting location of the macerator in your Roadtrek is causing a problem. The point I want to make is that you can mount the pump above the waste tank. Then you can have two options a macerator or the traditional gravity dump all on the same tank - the best of both worlds.

[Ron]

Received my information also from SHURflo, and you may be right, and I could be wrong, the more I read it I kind of believe you, but the last E-mail I received states it does not suck the contents, also when I had this problem with the pump, the Service Tech, said it had to be gravity feed to the pump.

Following Info is what I received from SHURflo folks:

01:
Ron, even though the SHURflo macerator is listed as self priming, the Roadtrek system is such that it is gravity feed, and even if the pump inlet were level with the tank outlet head pressure would force the liquid and solids to the pump. As soon as the valve is opened between the grey tank or black tank product runs to the pump until it is turned on at which time it is ground up and disposed of.

02:
The pump is listed as a self priming pump, but as I stated Roadtreks system has the pump at the same level or lower than the tank which in effect gives it a gravity feed.

03:
Ron,

This pump primes up to 5 FT when it is wet, although, we prefer if the pump is mounted below or at the same level as the gray tank, so the waste comes by gravity. If the pump is 5 ft above the tank, you will need to make sure the pump is wet inside before you run it, otherwise the impeller will get damage if it runs more that 20 seconds dry.


04:
Good Morning,
The Macerator pump will not "suck" the contents from the black holding tank. It needs to be mounted below the holding tank as it needs gravity flow.

Ron