WE have a pipe line 5.5'' with 80 m height recently we have a problem in sucking the ball while cleaning the line i doubt in ruber seal but it is very diffcult to reach the pipe line because of the site is complicated.and also may be it is the concrete i thaught that is the slump is less and there is a proplem in the mix the setting time is to small even we are using superplactiziser .so we are using water in the pump to clean the pipes every time and it is working nice.later we found the site became like sea because of the water so we are not allowed now to use the water any more.we tried today the comppresed air and it was good but the problem it is very dangrous may be the ball will hit somone specialy we are working in main loby for a hotel so any one has ideas about the safty of using the air?

Be careful use a PSI gauge and a Ball Catch. Make sure no one is standing by the end of the line when blowing out.

There are many methods to clean the line safely. Using compressed air is dangerous but efficient. I used it on towers in Las Vegas. We shot the concrete into the mixer or a concrete bucket. I recomened the mixer. We still had ball catchers on the end therefor you get to keep the ball and it all stays contained in the safety of the contained mixer drum. I highly recomend wetting the mud up a little before blowing it through. It makes it easier to push out. Good luck and any more help hit me up

thanks a lot

we willo try to put the concrete inside the mixer and we will use the ball catch

I once hear of a time when the sponge was blown into the ready mix truck and it broke out of the mixer went into and out of the cab of the truck and they could not find the sponge. They could only find the holes the sponge made. Has anyone heard of this story before

no

but a few years ago i was on a 1200m pour when we finished, had to blow line as i had pump to wash out some one else blew line picked end up of pipe line with backactor of a jcb brand new machine and put ball and concrete ii side cab blew it to bits what did they say ho were just get another one

Sorry Todd but that I just can't believe.. Even though it can be very extreem but that??? through the drum wall and through 2 walls of the cab ?? Sounds like a joke. Or was it a MACK?? than of course its possible ;-) hahaha..

Good Luck with blowing the ball!! If you do it right it shouldn't be any problem. Take your Time for it. 

thanks todd i like your mighty sponge ball i wish i can get five from it :))))

I think it was Bob who told me that story, i will email him abou it.

Todd:

 Lets have a contest with concrete pum[ping.com sweatshirts etc, as prizes. Funniest blow out stories extreme blow outs etc.   Guys this would not be something to slam each other as much as learning from mistakes and possibly laughing our asses off at some of the stories.  I know over the last 25 yrs. I can come up with a couple.   

I can think of a few but its often not nice but more like spectacular and happy no one got badly hurt.

I was blowing a bal through a 4''  15m long hose one time all by my self (I thought...) conected the air hose and just slightly opened the air. I walked down to the hose to put the end on the right place and just when i wanted to walk back the hose struck me on my lower legs and just completely blew me up side down... 2 big purple lumbs on my legs that evening...

Thing was that one guy from the crew was behind me with the truck and thought he just give me a hand and open the air pressure valve fully opened!! 

And then there was this one time when I worked as a finnisher and this pumper that was driving for us didn't realize the ball was stuck in the reducer and was building up huge pressure. The hoseman was not that bright eighter aiming the end at one of our trainees that was just with us for the 2nd or 3rd day. When the ball finnaly loosened up it was huge!! the whole wall was grey. a spot about 3 meters in diameter and in the middle there was a clean area in the shape of a man.. The poor guy was totaly full of crete.. in his ears and everywhere. His skinn was totaly red. He went straight home and I have never seen him again....

Last extreem one I can remember I was together with a colleage. 120m line with 20m 2,5'' hose at the end. He was at the pump.. I was about 30m from the end tapping on the pipes with a walky talky. I told him that when I gave the signal he should stop the compressor and open the releas valve to let all the air escape.

When I gave the sign about 30m before the end.. (so 10m before the 2,5'' line started)  he swiched of the compressor and then he said... ehhhhhh I used a lock without a release valve....

We ran for our lives and just had to throw our selves on the ground with our hands on our head.. The hose and concrete was flying everywhere. Realy insane. 

But maybe there is someone that has one of these happenings on video? That would be ''cool''

I've never used a stationary pump, but when running small line and using air to clean I drop my bottom gate on hopper, put sponge in placement end of system, hook blowout cap up, start pump in reverse and slowly,slowly put a little air to it. Pump will do most of the work, air just helps it along. I like it better than traditional blowout...much safer! Anyone ever tried this with a bigger pump?

Thanks guys for help,I think than next time I will try to reduce the air pressure and I will keep the pipes connected to the pump so the air will help with the pump while sucking the ball speciAly that last time the pump sucked all of the concrete except .25 m3 we used the air for it and in this case may be it will be sAfer than keeping the end of pipe line open or if we used the ball catcher but is this way will be harmful to the pump?

Far as I know it will not hurt pump...couple things I've learned the hard way being a mostly self-taught operator...always close the lid, never, ever put air pressure on system without pump stroking in reverse, never stop pump without first turning off air and bleeding pressure. Every time the valve switches you lose the air build up and air is expelled through hopper. Even with lid closed it causes concrete to hit hopper lid. One time I did not bleed air pressure before stopping pump reverse, but fortunately used my habit of always reversing pump before popping any clamp. On first stroke of reverse you can imagine the force that hit the hopper lid.

I trust one is using the proper blowout cap in doing this.

http://www.concreteconstruction.net/Images/Cleaning%20Out%20High-Rise%20Pumplines_tcm45-346486.pdf

Use the air to get ball past the boom and into stand pipe while you are sucking back.Then bleed off the air and see if you can suck the stand pipe clean.

You could always use water Shady, it is much safer than air.

http://www.youtube.com/watch?v=Hz5Z0YULdrk

Nice video, good job

Was just thinking..Do you suck back the concrete first out of the pipes before you put the ball in? What if you just stop pumping... Just suck back about 30 cm and than put the ball in straight after the concrete... Shouldn't that work?

Whit steel line you can suck back. Did it once in a greenhouse whit 100 meter of 5" steel line gave a big mash behind the pump but it was better than blowing whit all that glass.

nice site jono   but now we are not allowed to use water any more because we dont have a system like yours

dipstick the pump is sucking around  80% of the concrete in the pipe line without water or air but alittle is staying so we have to use water or air.