Hi next week i ll be filling an old artesian well thats it s filled with water.I ll pump threw my 32m boom reducing to 3 inches before dropping 25 feet and then reaching 50 feet horizontal. All my 3 inches will be filled with water.How would you prime?I ll prime my boom first and do i have to care about the water?I taught priming like any other line job i do.With grout directly at my reducer and prime it very slow.It will be special mix for in water poor.Do i care about 25 feet drop?Is it better to use a 3 inch sponge before the grout?There will be a diver underwater and we will have to 8hours day of pumping.Thanks

See if you can get a yard of grout and hook it all up. Sounds like it will be a pain if you miss your prime 

make sure that diver knows to make sure he has no uncoverd skin 

Since it is just a well fill, use bentonite. You can mix it up in a mortar mixer, fill your hopper full then when concrete gets there, pump the bentonite into the boom and then chase it with concrete! It will stay viscous even in a water enviroment, and is a great primer! In the old days, we used it to push a rabbit through a long line (1500') and then primed back into a holding tank ,and re-used it!

supprised not one suggestion of covering the end with plastic,keeps water out on prime

just say'n

I would absolutely put a ball ahead of the grout.. I would be afraid for seperation. The ball will help a lot.. maybe the covering up with plastic will help also but the clambs might leak a bit though.

Many has the right idea use a grocery bag on the end hose its called poping a cherry you don't want water to wash things clean if you do it will plug big time.

Poping a cherry  Like that one.. I think you guys are right.. No good with all that water in the hoses..

if you do put a bag over the line and not allow water in it will create buoyancy so you will have to attach weights to the system or fasten it somehow. I'd just put a sponge ahead of the prime to push the water out ahead of the grout.

I think it will easier just to call a meter of grout with a sponge ahead.?thank you everyone,it worth a lot of money what i learned here.keep it hard!!!

I'm with dipstick, better put a ball or wad in front of the mud or bad things will happen.

I pumped under water with a 34 meter last year (flat out onto a over-water temporary walk-way, two 90s to get into the water, and 100ft off the 90s) with two divers. Obviously it was all secured and the hanging hoses were pinned and held with steel choker straps.. I pumped 1 Yard of grout, and used an underwater concrete mix .. didn't have any issues. didn't need a ball or anything, just pumped out. At some points I waited up to 1 hour per truck, and had no segregation issues or plugging on restart.