Multi-effect evaporator test after retubing

[JManrique]

Hi everyone.

I'm working in a MED-TVC desalination plant turnaround. The evaporator has 4 effects, and 2nd, 3rd and 4th efects were retubed due to corrosion issues. The internal configuration of each evaporator effect implies that we can't fill up the tube bundle chamber to the top of if (shell side) because it's connected to a second chamber where the steam generated by evaporation passes through a demister and feeds the next tube bundle (tube side), all with the purpose of doing a watertightness test and check if the rubber devices on tube-tubesheet joints were correctly installed and no leaks are present.

This test was a proposal of the QAQC department, but neither this test nor other different one is indicated by the vendor in the O&M Manual. The problem is that this proposed test won't cover the 100% of tube bundle, so we won't be able to check for leaks in the whole joints.

So, the question is:

Is there any kind of procedure for testing if the maintenance done in the effects (retubing) is acceptable? How could we test the 100% of tube to tubesheet joints for leaks?

If you have any experience with seawater desalination retubing, I'd appreciate any suggestion and advice.

Thanks in advance!

 

[TugboatEng]

Leave the feed water connections open to atmosphere and draw the casing of the unit in to vacuum. Any leaks will result in a loss of vacuum.

 

[EdStainless]

and These leeks can then be found by using an ultrasonic listing device, or maybe by using a spray bottle of water. Where you think there is a leak wet it and if the water either plugs the leak or gets sucked in then you found a bad one.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, consulting work welcomed