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What should be ED and UF parameters for a low turn over ED bath

February 1, 2009

Dear Sir,

I am looking after a customer's ED bath with parameters NV 18.9%, Ash 17.7%, pH 5.8, Conductivity 1706, Solvent BC 1.17% and Acid MEQ (milliequivalents) 30.8. Applied voltage is 240 volts and thickness on bodies is 18-20 um. Our ED bath production is low, i.e., average 50,000 sq meter/month. We have different body sizes ranging from 70 to 110 sq meter/skid (parameters, voltage etc, same for all).

Our UF Rinse Bath and UF Permeate parameters are conductivity 1530 and 1535, pH 5.55 and 5.52 respectively.

We are facing problem of roughness/outgassing on bodies especially on doors and front panels, rest of the body is ok. The PT condition is also questionable, but since I am an ED services officer to the customer, so I want to make sure that the problem is not due to ED.

Else, related parameters are as follows:

Coating Time: 4 min
Ramp up time: 55 sec
UF Flux: 3000 L/hr (Flow of Permeate to UF Rinse Bath only not to ED Bath)
ED Bath Size: 165000 L
UF Bath Size: 125000 L (Only one UF Rinse bath, then DI Water Rinse)

To the best of my knowledge, I have been taking care of this bath as my baby, but may be if I am lacking something, kindly let me know. Most importantly what I want to know is that are the ED, UF and Permeate parameters ok? If you need any more related information, please feel free to ask.

Regards,

Safwan Iqbal
ED Services Officer - Karachi, Pakistan

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Q. I want to Know in detail about the Ash Content & MEQ parameter

Hari V
ED Emplyoyee - Chennai
January 7, 2010