i have a 280yd pour at midnight tonight.it's a 4000 psi mix with 57 stone [ 2.5in ] 4in slump plus hrwr [plastersizer] the mix is not the problem it's the fiber [horse hair] as i call it.20 lbs per yard. and my question is have any of you ever pumped it through the 4.2 pipe? i have pumped it quite a bit with my 52m schwing 5in pipe [125mm] and gets rough sometimes.so just want to here about anyone else's experiance's with the smaller pipe.and a putz. lucky me..

shouldnt be a problem just did 280yd on friday 4000 psi no super p . 4" slump +/- 1" (so you know they brought a 3") oh and i for got had 300' of 4" and 1 1/2" steel in it aswell all that being said just go slow. she might bitch and moan but it will go.

Never had a problem.  It'll be fine.

You have to remember more hose or pipe is always the enemy. But in your case your lose pressure going through a shorter boom, quiet a bit shorter at that( 52m to a 40m). Big difference. Just like everyone is saying slow down and an occasional shot of water in the hopper wouldnt hurt. In your hopper of corse. If you wet up anything enough it will pump. Just talk to the contactor about your concerns and explain the possible problems that could arise and you wouldbe surprised at the results you could come up with.

thanks for the info .only takeing 30ft 4in hose might not even need it.slow it will go,only planning on 30cyd's an hour so about 9.5 hr's till wash down.should be a good pay day.

OK  I want to see 2.5in stone thru 4" hose @ 4in slump. Pictures please

57 stone is used in 90 percent of our mixes.it's a mix of different aggs from 3\8in up to 2.5in .i would love to take some pic's but unfortunantly feb 23rd my house was robbed and my brand new video camera along with everything else worth anything was stolen .but it is a good pump mix,4in slump on job before hrwr [super p,plastersizer] water reducer.should be about a 6.5 to 7in slump without the fiber. around 5.5 to 6 with: i hope;;;   

Oh I see.  Sorry your privacy was violated.  Awful feeling.  I took pictures once and the Amish guy said they believe it takes away part of their soul.  I am not sure it didn't have something to do with child labor law. Anyway I put it away.

 thanks for the input job went well only needed two hose's pumped good and took 9.25 hrs right at 30cyd's per hour. 

Telealbelt  i think you misunderstood the rock is not all 2.5" that is the maximum size the 5 and 7 in 57 stone refers to the holes in the screen at the mine