EPRI TGUG workshop

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stator cooling water systems


Welcome to the first SvoBaTech newsletter. We will keep you updated with the latest news and some useful information on a topic related to Stator Cooling Water Systems.

In this edition we will talk about what to look for to spot plugging in the stator cooling water system before you lose output or even lose the machine.

EPRI workshop in Amelia Island, FL

Mat Svoboda will give a talk about “Monitoring Stator Cooling Water Systems” at the next EPRI TGUG meeting Amelia Island, Florida, Jan 19-23 (for more details, click here).

Visit us at booth #21 at the January EPRI TGUG on Amelia Island, FL and win an iPad or a VISA gift card.

The SvoBaTech team will be present and happy to answer your questions.

WIN an iPad or a $100 VISA gift card

Publication on SCWS chemistry

PowerPlant Chemistry magazine

Two papers about alkalization of Stator Cooling Water Systems have been published in the latest PPChem issue (for more details click here).

—> Did you know?

How do I recognize Stator Cooling Water System plugging?


Plugging in the stator can lead to power limitations, forced outages, damage or even major equipment failure. In order to avoid this, it is important to detect signs of plugging early so that you have enough time to take action.

» During operation

   Copper oxide plugging can be detected by individual Teflon hose temperatures:

Heating of the water in the stator depends on two factors: water flow and generator load. Plugging can be spotted by observing the trend of temperatures differentials across the stator.

Also an increasing spread amongst the bars indicates that some are plugging up.

Temperature graph

   Another indicator is the relation between flow and pressure drop across the coil:

Flow and pressure drop across the stator have to be put in correlation, as each depends on the other. This relation can provide hints on global flow restrictions in the coil (this also works for filters and strainers).

Individual bar plugging is not as readily visible with these parameters.

flow and delta p graph

» During an outage

   Copper oxide plugging can be detected by ultrasonic flow testing (“Doppler flow”):

With ultrasonic flow testing, flow in every individual Teflon hose can be measured. This is comparable to the individual temperature measurements during

Typically, flow rates should be within ±5-10% of the average. For details, consult your operating manuals.


   Visual inspections give the clearest picture:

Inspecting the water boxes (where most of the plugging occurs) with a borescope is an excellent method to spot oxide deposits and plugging. Visual inspections often show problems before the other parameters react. However, for the inside of the bars, only indirect methods such as the above mentioned must be used.

Water box borescope before and after chemical cleaning

—> Next newsletter topic: “Getting rid of plugging”

Find more details about the stator cooling water system on our homepage
or send us any other questions per

Visit us at booth #21 at the EPRI TGUG January 19-23, 2015 .

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© 2015, SvoBaTech, Inc.

SvoBaTech Newsletter No 1, Jan 12, 2015

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