The high grade condensateis involved in the contamination is made up mainly from the steam exhaust of 500 # steam turbines ( 7 in total). This is why we wonder how likely is for the lub oil employed in these turbine to be the source of the contamination. Unfortunately when this event ocurred...
Thanks for your kind feedback hacksaw, springrise & EdStainless.
We used a corrosion inhibitor based on 5 to 10 % NaOH among other components. When we noticed the pH reduction, we increased the dosing of this chemical to overcome the situation.
Question; under what mechanism could organics...
Thanks mk3223 for your feedback...Yes indeed it's been hard to find out the source of the HC/oily contamination. We are not quite sure if the reduction of boilers ph and the presence of oily material are separate issues or not, since this pH reduction took place whilst we experienced this...
Greetings,
We experienced an oily contamination (*) in the high grade condensate used for four 550 psig pressure boilers. During two days the ph of the boilers' blowdown were detected by portable analyzers getting reduced from an average of 10 to about 6.5 - 8.0. Any ideas what might have...
Thanks again for the feedback. I will answer soon, but just to clarify a couple of things: The drawing shows the same line in two different positions. The line was increased in size, as I said, from roughly 68 feet to 76 feet, after we got indications that the line might could be restricting...
Yes, it looks that there is some issues with the drain line. Would it has to do with the orientation and/or relative position with the stilling well-thermowell pipe (SW-TWP)set? Should it be a defined angle relative to the SW-TWP set?
Please find attached some drain line details.
Thanks...
Thanks for all feedback so far, they are really helpful.
Providing some more clarifications:
A) Yes, indeed is an external FR
B) A summary of tests and their results follows:
a. With drain line (DL) 68 ‘ long, tank hydrotest (THT) passed, but after draining completely, 10 tension springs (TS)...
Sorry, I meant to send this other file as well....https://files.engineering.com/getfile.aspx?folder=a0b51132-bbbf-4865-984a-40d00fec0e4b&file=Floating_Roof_Orientation.png
Apologies for late response. I had internet connections issues. I appreciate all of your valuable insights and comments.
Answering some of the questions:
a) Yes, the pontoons, stilling well (SW) and thermowell pipe (TWP) are new.
b) Verticality of SW and TWP was checked and are ok.
c) Drain...
A 72' diameter tank x 48 feet height, single deck floating roof tank has been overhauled (overall roof, support legs,and roof drain line replaced,along with some parcial repair made to the bottom plate by patching some small portions). After conducting hydrotests, we observed that the roof...
What is considered to be Pitting Corrosion and what are the main causes/factors that determine it in CS heat exchanger tubes? In turn, what are the answers to these questions for the case of Uniform or General Corrosion?
Thanks!
Thanks Dhurjapati, capla79 & mrfailure for your feedback.
Responding to some of your comments, we did have thought of sulfidation taking place, but as mentioned, temperature at outside tube wall is lower than 450 F, at which this phenomena occurs. We are sustainably around 420 - 430 F. Using...
There is a 4 tube pass/1 shell pass heat exchanger experiencing failure (leaks) at some especific middle tubes of the 1st pass (6 tubes out of 125 total in the 1st pass). Localized corrosion seems to be taking place on the tubes outside, toward the floating head. Process conditions / are...
thread1203-186657
I have seen throughout this forum many threads dealing with PSV chattering. One of the causes for this phenomena being valve over sizing. Accordingly, to avoid it Required capacity should be greater than 25 % the Rated capacity. Does anyone know and can provide a reference to...
