Hey guys - so, we'd like your thoughts on this. What's the SLOWEST you've ever pumped through 2" steel line on a continuos basis, without it setting up in the line (starting to build up on the sides of the steel pipe). Assume a typical 4000# pea gravel mix, pumping underground (so heat isn't an issue)...

What has your experience been? - at what velocity will the cement start building up on the sides of the pipe?

Thanks!

- Mike @ REED Pumps

I have no experience with 2in steel, but rubber and shot Crete yes, can go along ways and pretty slow. Now running a boom pump and belong to a ready mix outfit, we experiment allot. The question is about the 2 in steel, my biggest concern would be the valve and reduction to get to the steel, it should build up and stop before the pipe, now that's just what's happened to me, delivering one shovel full at a time. How slow is really pending on what's pushing it hehe. please correct me if wrong. I guess if you just had a steady push, through steel, you could go as slow as you like, as long as hydration was not an issue, kinda like water in winter keep it moving. Or are we looking for a true, scientific number.

I dont think your concern should be the 2inch pipe rather moreso the concrete valve. The 2inch pipe will always have a nice velocity of concrete going through it. The valve which has a larger diameter will just build up a ring inside eventually to the size of the 2 inch hose. Then you will get feed problems (not to mention cleaning). That should be your biggest concern.