[tom]

Only problem I had with my polysulfone head was my fault. Evidentally it's not built to survive a 5 foot drop with a ball valve on it. A replacement head was only 20some $. I got a second one while I was at it. That should prevent any future failures. Although I would love to have a SS head. The motor has lasted at least 10 years.
Anyone have a center inlet model?

[bob]

I've used the march-809.  It's flow rate is a little anemic, but it works.  I just purchased a Little-Giant 3-MD-HC, which is reported to have about twice the throughput as the 809.  It is also a centrifugal mag-drive pump, like the march, and comes with a Ryton head (similar to the March plastic one).

The Little Giant pumps are rated to 200F max. Maybe the same materials but not the same rating. I have th L.G. TE-3-MD-HC and have used it for about 60 batches over 10 years. The impeller has a black carbon bushing that just broke and a new impeller is $46. Might be good to have a spare or another option. I'm going to try replacing the bushingor part of it with a stainless steel homemade bushing and see if that works.

The pumps are ok but I would like to see a higher flow rate. 15-20gpm. With hoses and fittings and 3-5 ft of head in the system, the flow rate is about half of the rating. So I'm looking for a bigger pump, in the meantime.
Bob