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

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'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

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.