Today's work mess !

[ahardb0dy]

We had three 24" reclaim valves to exercise (make sure valve is fully open than fully close it and reopen, the machine counts the turns for us) left over from last Friday's work, we do large potable (drinking) water valves 16" and larger usually up to 30" Tuesday thru Thursday and on Friday we do large reclaim valves.

 

We exercised all three and left the valve at the end of the line closed as our GIS map showed there was a blow off after the last valve, a blow off is where they install a 2" pipe coming out of a cap or plug in a valve or on the end of a section of pipe and than 90 it straight up with a 2' valve that sits in a meter box so the line can be flushed if needed,

 

but the blow off was not visible so I didn't really know if there even was one plus the street is fenced off and there is nothing on it ( no development yet).

 

After we finished the third valve we drove back to the first valve to make sure there was not any problems or leaks and we found this:

 

 

this was after going back and closing the other two valves as the first valve would not close fully and the water was still running, The water pressure lifted the valve box with the concrete still attached right out of the ground, it is upside down behind the sidewalk.

 

 

While ribboning off the area, water started to flow again and I didn't know where it was coming from until I realized it was being pushed up as the 2 sections of sidewalk fell into the hole, next picture is how it looked after that:

 

 

The best we can figure with out digging the pipe up is that the valve blew off the end of the pipe.

[Precise1]

Quite the mess, but I can see how it can happen. Valves can stick, as you well know as per the exercise, but they are supposed to stay in place, as well as caps.

What too many people forget about water and PSI is that water is relentless and can do a hydro hammer, but PSI adds up quick! 24" valve is technically 450 square inches, so...

 

B

[JamesRich]

Here is my work mess! Has been for the last couple of days and I have a few left!

When you put three 61,000 pound machines in a row on the slab of a 40 year old shop the floor will constantly sink! As the machine looses level it also looses accuracy. When you have to hit tolerances in the tenths of a thousands you have to keep re aligning the machine. If I let mazak do it by themselves I get the "close enough" excuse.

I have to stand their and help them do the mechanical part, while cracking a whip, then I do all the parameter alignments myself. The maintenance guy at our shop doesn't even know how to align these machines. I had to learn just so I could get my machine cutting the way I want!

Then as if this isn't enough pain in the ass the high tolerance job I have coming in 718 inconel will probably take the little sanity I have left! I need a new job!

James

[ahardb0dy]

I know, any valve or fitting that is at the end of a line is supposed to be restrained either by mechanical means or in the old days they would use a thrust block, concrete poured in the direction the fitting may move, that's the bad part about when new lines are installed if the inspector isn't paying attention you have no idea what is going into the ground until something like this happens and it gets dug up. My boss was off Friday so he doesn't know about this yet, if/when they fix it I will find out what happened.

 

Today's code specifies anytime a fitting is used the joints of pipe 3 back on both sides of the fitting need to be restrained and no more concrete thrust blocks.

 

Years ago at my previous job we pulled a thrust block out of the ground that took up half our flat bed, was like a giant boulder !!

 

I don't think all the 24" valves on this line are fully open, there are like 14 more valves we did not have to check, I think if the main was under full pressure and this 24" valve came totally off the pipe there would have been a much bigger hole, that is based on past experience.

[Precise1]

Ahh, I didn't know about thrust blocks, but it makes sense!

 

When you put three 61,000 pound machines in a row on the slab of a 40 year old shop the floor will constantly sink!

What? Machines that size are supposed to be put on their own floating pad, usually 1+ feet thick! They just plopped them on a regular cement floor? Idiots!

 

I worked in a shop with a fair sized Kitamura horizontal with tombstones. They straddled 2 different pads and 1 crack (because that is where it 'fit') yet couldn't figure out why they kept losing alignment...

 

B

[JamesRich]

Ahh, I didn't know about thrust blocks, but it makes sense!

 

What? Machines that size are supposed to be put on their own floating pad, usually 1+ feet thick! They just plopped them on a regular cement floor? Idiots!

 

I worked in a shop with a fair sized Kitamura horizontal with tombstones. They straddled 2 different pads and 1 crack (because that is where it 'fit') yet couldn't figure out why they kept losing alignment...

 

B

 

 

You guessed it, that is where they fit! You are right on the Idiots comment too! This shop used to be a manual shop with a drain along the middle of the floor. They filled the drain in and put the machines over it.

We had two huge mazak horizontals with tombstones too. They were on the other side of the shop but both on the same side of the filled in drain. One of them left last year but we still have one. They never have trouble with the alignment on them but they never do 5 axis work either.

James