Funny Engineering Pictures

[Dleg]

We've had a couple over in the Environmental forum. But I think this one is too funny keep to the enviros only.

What do you do when you install one run of pipe in two sections, starting from both ends, and then find out they don't meet up at the same elevation?

See here:

 

[Dleg]

This was an 8 inch air line from the blowers to the aeration tank at one our two sewage treatment plants. The utility kept having to replace the blowers because they would burn out every couple of months, and they even replaced the entire aerator assembly to try to correct the poor performance.

Finally, after nearly ten years, they started digging up the air line to see if there was a break or something.

Here's the inside: (remember, this was supposed to be an 8" pipe)

 

[Dleg]

Oh yeah, this was supposed to be an invitiation to post other funny engineering pictures.

 

[Fudgey]

 

[DVINNY]

Once again, Fudgey RULES

 

[EdinNO]

On the pipe, what did they do, blow toch and melt it down?

I don't see why they "crinkled" it up like that. Were they trying to heat it up to bend it and "persuade" it t meet up wit the other pipe and it collapsed like that? :dunno:

Ed

 

[MetroRAFB]

ED,

That appears to have been their intent, but anyone with a pulse should have known that wasn't going to work. I've had experience in the field with heating and bending PVC pipe, and there are limits to what you can do without constricting it too much. Some field monkey on THAT job should be shot.

:dddd:

 

[EdinNO]

He probably said, "Heck with it. Engineers always overdesign things anyway" or "By the time they find this, I'll be long gone".

Ed

 

[McEngr]

He probably said, "Heck with it. Engineers always overdesign things anyway. By the time they find this, I'll be long gone".
Ed

The wannabe engineers, aka draftsmen, at my office call it O.K. engineering. O.K. = overkill. Yup they're geniuses that need to show us the ropes .

 

[MetroRAFB]

The true beauty of that situation is that the engineer is in the clear unless he/she spec'd out that particular melted fitting.

 

[RIP - VTEnviro]

We specifically include things in the plans and specs just to cover our ass like that. We know damn well the contractor isn't going to follow half the safety protocols they should.

But, we call it out anyway, so we can always say later, "It was on the approved plan. Not my fault they ignored it."

 

[MetroRAFB]

Yeah, construction plans are covered with disclaimers for the engineers. Basically the contractor is responsible for doing it correctly, even when crappy engineers design something that doesn't even meet code. The disclaimers usually say that the contractor is responsible for installing stuff per the engineer's design AND applicable codes. So if he installs something wrong just because the engineer said to do it, he's still screwed.

 

[EdinNO]

We've had 'em that say code takes precidence over the engineering docs in case of a conflict.

Ed

 

[RIP - VTEnviro]

I think I've heard that too. Engineering docs are professional judgment, code is law.

 

[Dleg]

You guys are giving our contractors waaaaayyy too much credit here. I wasn't there when they did it, but I can say with 99.99 % (four log!) certainty that not one of the guys who did that once thought about the engineering or the consequences. It was probably just a "damn! Just melt it together so we can go home" kind of thing. :dunno:

 

[Mike1144]

I don't see scorch marks. And it looks like a regular collapse pattern. Could this have been caused by a hot fluid flowing through?

 

[Dleg]

Hmm... Interesting possibility. The pipe was used convey air from standard blower units to the aeration basins at a sewage treatment plant. I'm not sure the blowers heat the air enough for that to happen. And I'm not sure the pipe was long enough for expansion to have caused a collapse like that (around 100 feet) My thought on the lack of visible scorch marks was that the pipe had been buried for 10+ years, and the scorch marks degraded in the moist soil environment?

 

[EdinNO]

Its possible there would be no scorches, just melting. Maybe we have to do some tests? Anything in the budget for some forensic engineering?

Ed

 

[MetroRAFB]

It's very possible that you could heat the pipe enough for to collapse as shown without leaving any scorch marks. Scorching occurs when you place the heat source too close to the pipe surface. Conventional PVC heaters have rollers inside them, the pipe lays on those rollers and you're supposed to keep the pipe rolling while it's heating to prevent scorching. I'm not sure whether or not they make that style of heater for pipe that large but I imagine they do. The other method I have experience with for small PVC (3/4", 1") is to use a heat gun (glorified hair dryer). I doubt you'd be able to heat pipe that large with a heat gun but it might be possible.

 

[EdinNO]

metro,

You may have mentioned in the past, but what do you do work-wise? It sounds like you have some experience with PVC. Just curious

Ed