Hello everyone, 

I have a job on apartment buildings and we have patios to pour. We are pumping through the building on upper levels because of no access to the rear of the building. I have never pumped with my boom through 2" hose. It is pea rock and 6 sack so good mix i hope, 100 ft of hose tops. Any tips or concerns. I would imagine pump slow ??? Thanks

I always drop the pump down a few gears when pumping through small line myself.

Be careful of air in the system. Any disconecting for a plug or moving the boom can lead to air in the system which means POW! when you start again. I dis like running hose off of a boom because when in "A" frame position or vertical the mud can roll back when idle and create air pockets.

that's why you need an air cuff to hold the boom full of concrete ;-)

I pump off my boom with 2" all the time, just ask for grout to prime and turn down your pump strokes!!

i refuse to use 2" line from 9" barrels.  had a very near miss/incident.  to much pressure IMO.  2.5" is as small as i go.  been kicked off rezy jobs for not having 2" line.  a half inch may not seem like much but i notice a huge difference and have not had the same issues with it.  i go low rpm.

IMO 2" line is for 4" barrels

im with you dipstick.  the only time i used 2.5 inch was for high flow mix for 1.5 inch wood subfloor topping.  slow pumping and long time jack hammering the hopper and S-tube.