Ok. This happened to me several years ago. We use Blow-out caps with 2 ports on them. 1 for air, the other water. Both ports have their own shut-off valve. One of our 45 meters plugged while pumping at Southpoint casino in Vegas. Operator called in and I went out in the service truck. A-framed the boom to attempt to blow it out with our blow out cap. Unfortunately, too much time had passed and we were unsuccessful. I closed the shut-off valve and removed the air hose. I then opened both valves on the blow-out cap to release the air pressure trapped in the system. Minutes pass. I wiggled the valves to dislodge any mud that may have clogged the valves and prevented all of the pressure from escaping. I was sure that all the pressure was depleted. I was wrong. Popped the clamp off and the blow out cap blew off and hit me in the thigh. Nasty bruise for awhile after that one! I now have a healthy respect for systems under pressure! Never stand in front of system being taken apart unless you are positive that it is safe.

Probably 20+ years ago a good friend of mine from Atlanta had a horrific accident.David was an exremly tallented operator but forgot one day.As I recall he was on a placing boom job doing a blowdown.He unclamped the cap and it hit him in the head causing severe head damage.I heard about 2-3 weeks ago they had to place him in a nursing home,unable to care for his needs.

Anyone that doesn't think it can happen to them is badly mistaken,safety pays.

Ball valve pumps can have over 900 PSI ,I am extra cafeful when unpugging a line away curve the hose at the coupling in a horse shoe design and get on the inside of the curve care when the clamp is remove it will blow away from you and always use a shovel or a long hammer the get the clamp open.

David Bone.

The man could move concrete. I worked at BBCP in Denver back in 1983 for a couple of months with Dave before I took unit #2 (think about that number) to Dallas. The man is the pioneer of this industry for me. Rebel to the management( and mechanic), master of the pump, the operator the customer wants. My hat is off. thanks for reminding me of him Roy.

Matt

Hello Matt

I haven't talked to you since that 400 lb guy at the west menphis scales had me bent over the desk (grin).Yes,David was a rebel and I would have never thought that could happen,especially to him.I just can't explain how much air worries me,even to this day.To the old hands,it's your job to help educate.

Matt,I'v searched high and low for pic's of that Perinni job in DC (Regan build).If you have some please post'm up,that was a job from heck.

When I go into the office next week I'll see what I can do. Those pictures were before digital so I'll have to scan them.

Sorry to hear that about David, I worked with him in Atlanta.  Yes he was a rebel, amoung other things, but he could get the job done.  One day he finished a pour and got his sponge back after pumping his cutting ring out the end of the boom, no B.S.

Chris

Yes he was a rebel, amoung other things

Yep,that was David,a master.Don't know if you followed this thread.

http://www.concretepumping.com/index.php?mode=newboard&act=topic&tid=6148

We also had similar blowout caps at are yard in vegas. We built them. Both valves were for air though. One side would feed the air and the other was for bleeding off or draining the system.

can never understand the thinkin in blowing out a plugged line with air- if you cant move it with the pump creating up to 85bar or more how is 10 bar of air (or less) supposed to do it???  The caps may have two fittings with one to release ,but the danger lies when the air goes past the ball.

Many,

I knew about Tom also, he was a great guy.