Sometimes You Just Shouldn’t Jump In Feet First #FailFriday

Apr 10, 2012 // by Rob Drysdale // Blog, Professional Development // No Comments

Pipeline im Bau (Photo credit: Wikipedia)

Thinking about it, this could also be titled “There’s No I in Team” or “Communication is Key”.

About 20 years ago I was a young(er) Engineer working away at a company learning all about how things worked. I was given the task to look after and inspect a pipeline project that was about 20 kilometers long. One of the tasks at the end of the project is to test the pipeline before it is put into service. The tests are done with water and the pipeline is pressurized almost to its full theoretical yield strength.

In the days leading up to the tests there wasn’t much for the inspector (me) to do so I helped out the contractor doing some menial tasks on the site. One of them was filling this long pipeline with water. We used a small water pump that pumped at a maximum of about 200 psig. Not much compared to the full yield pressure we were going to test at. As you can imagine when you are testing a pipeline at over 1,000 psig you have to use some pretty heavy duty fittings so we could pretty much do whatever we wanted with that little pump…including closing the valves with the pump running. Remember this as you read on…

The day of the test everyone got there, we set up the test assembly, the dead weights to measure the pressure and a high pressure piston pump. This piston pump can pump in excess of 3,000 psi, but it pumps relatively slowly compared to the pumps we used to fill the pipeline. But think about it, water is incompressible so if the pipe is already full of water it doesn’t take a lot more to get it to the test pressure. I forget the exact values, but it was probably about 400 to 500 gallons of water that we needed to pump in.

So we started pumping water and found it was taking extra time to get the pressure to rise the way it should. Sometimes you see this if there’s a bit of air in the line, but in this case the pump just seemed extra slow. I had been on tests before (and had them go wrong before) and I knew (or thought I did) what was happening. We stood at the top of the excavation looking down at the test head and wondered what was wrong. Without saying anything to anyone, I jumped in the excavation and put my ear next to the valve. It didn’t sound right to me. So guess what I did….I closed the valve. In my mind I thought there might be something in the valve and if I closed it and opened it again right away maybe it would help. It was a sound theory, right? Wrong.

Remember what I said about using heavy duty fittings? The valves were 2” ball valves rated at 3000 WOG or 3,000 psig. Remember what I said about the piston pump being able to pump in excess of 3,000 psig? Guess what happened when I closed that valve WITH THE PUMP RUNNING? Let’s just say I never got the valve open again. I took the top of the valve, the handle and the stem in the chest. Lucky for me I was bent over the valve far enough and it was late fall I was wearing enough winter gear it wasn’t too bad. I got a face full of water right away so I didn’t even realize I got hit by anything else. It wasn’t until later that I started feeling a dull ache that let me know.

I was working with a team. Had we actually talked about the issues and what we should be doing I never would have dead headed such a strong pump against a closed valve. We may have closed the valve and reopened it based on my theory, but we would have shut the pump off first.

Sometimes you just shouldn’t jump in feet first.