Proper Method To Abandon Cooling Water Lines? 1

[mbogema]

I've got a cooling water system sprawling an entire plant. The lines were installed in 1990. Due to layout changes, we will not occupy an area in the plant. About 2,000 ft of 4" dia. supply and return piping will no longer be used. The plan is to abandon the pipe in place. I've got a way to isolate it from the system. My question is: Other than draining the lines, is there a proper way to abandon these lines for possible future use? Perhaps there is a chemical treatment available? Future use could be as soon as 6 months or as far off as 5 years........

 

[MJCronin]

My suggestion..

Do not drain the lines, but contact a reputable water chemical supply firm and add a "rust inhibitor" to the water filled system. You may have to install a temporary pump and connection points to ensure a uniform concentration in the system.

Vent the system as necessary, install pipe caps at the termination points and install a "keep full" valve(with a connection for a pressure gauge) at the high point. Keep a record set of drawings with all changes made to the system. Record the type and concentration of the inhibitor on the drawings. (You may not be around in five years to answer any questions....)

Understand that the corrosion process needs oxygen to keep going. Once the piping is capped and the fluid is stagnant, no further internal corrosion will occur.

None of these actions addresses any external pipe corrosion, which should have been addressed during the initial installation any is out of your control.......

Good Luck

MJC

 

[dcasto]

Another method would be to wash and drain the lines and then vacuum dry them. Cap them with a dry nitrogen purge system. Keep the records on the material of construction and welding so they can be used again.