Software solutions 1

[kepharda]

My problem involves a fuel transfer pump. Each time my client first turns it on (1-2 times a week) to pump fuel from the holding tank to his truck loading rack, the pump creates a pressure surge which is breaking piping mounts. The pipe is visibly moving 6-12 inches depending on the location. Once it has been started, subsequent restarts cause no problems.

Luckily I did not design the pipeline, however, I am interested in what other engineers would suggest in the way of modeling software to root out the real problem. I am not looking for anything free, but really just ease of use and say less than 20K a seat.

The specs are 6"-8" pipeline, about 1,143 feet long. The pump is a Goulds Pump 3196 4x6, 1200 GPM. I walked the pipeline today and there are a couple of things that don't look right, but I would really like to model the thing and see what I can come up with.

thanks for your reply's in advance

-dave

 

[kepharda]

BigInch, that is exactly what I am assuming is happening, I believe small amounts of product (transmix) goes thru the relief back thru the centrifugal pump to the tank.

I am calculating the pipeline head as I write. I am just estimating there is approximately 2.5 times as much head as is required.

I was out on site looking at the pipe supports today trying to figure out how we can fix them and while we pressurized the line just the other day, today the Bi-metal pressure gauges all read zero PSI.

Although with the transients they (Press Gauges) have seen, I doubt they are too accurate anymore.

Even for US Government work

this message has been approved for citizen to elect kepharda 2008

 

[BigInch]

Do you have a check valve or something between the pump and pipeline?

[pump]-[check or valve]-[relief back across check or other valve]-[pipeline]

I don't understand how the relief valve is supposed to work. I don't see how you can relieve anything into the pump discharge when the pump is running. What is it doing? Just providing thermal relief when the pump is off?

Ya, 2.5 times the head and no telling how much torque you've got coming on at startup will knock the socks off that line.

"If everything seems under control, you're just not moving fast enough."
- Mario Andretti- When asked about transient hydraulics

http://virtualpipeline.spaces.msn.com

 

[kepharda]

Yes, the relief is just thermal when the pump is off, I looked at all their pumps and this is the standard way they install them.

And yes again there is a check valve between the pump and the pipeline.

this message has been approved for citizen to elect kepharda 2008

 

[BigInch]

Fine. As long as its not supposed to be anything but thermal relief when the pump is off, that's ok. So, product is either leaking through the check or relieving and returning to suction through the pump.



"If everything seems under control, you're just not moving fast enough."
- Mario Andretti- When asked about transient hydraulics

http://virtualpipeline.spaces.msn.com

 

[kepharda]

Finished calculating the required pipeline head.

Even with a conservative estimate I am only finding about 109 total head due to line losses and elevation change.

The pump installed is rated at 300 ft of head at 1200 GPM.



this message has been approved for citizen to elect kepharda 2008