@TheHandModel
It was the same containment shell, the bottom picture was when pressure test (operating pressure) was done on the containment shell. The crack formed shortly after.
I suspect that the dust come from condensed nitric acid that leaked through the containment shell during normal...
Continuing my old thread https://www.eng-tips.com/viewthread.cfm?qid=490736
Does anyone ever experience this issue? We've recently extended our inspection from 3 months to 6 months and see that the scratch mark on the containment shell was more appearing than 3 monthly inspections.
@BlaineMS...
Hi BMW,
Would you like to share the pictures please? I am curious with your failure events.
We have confirmed that:
1. NPSHr is below the NPSHa
2. Suction pressure is 350 - 400 kPag
3. Vibration level are normal throughout the time, (0.1 - 2 mm/s)
4. Alignment always performed during pump...
Hi MJCronin,
We got the replacement from Flowserve USA via our local distributor. We never repair the broken containment shell. Our current approach is as soon as we find any leaking, however small, we replace the containment shell immediately. - a costly approach but necessary to avoid plant...
Hi all,
We got high vibration on 1.66X shaft speed of a vertical cantilever pump (at 2250 cpm). The RMS of Motor NDE bearing is 13 mm/s (being the highest). The motor is variable speed with rated of 1475 rpm. During the measurement the speed was 1349 rpm. Any thoughts on why this is happening...
@TiCl4
Hi there. We are absolutely agree with your statement. Yesterday I have sent the containment shell to external lab for failure analysis. Whether the containment shell was damaged because of chemical attack or because of friction with impeller due to thrust balancing. I will update it...
@Pierre
Hi Pierre, so far we do not have any big issue on the downstream control valve (LV12005 as in P&ID below)
@Compositepro & MJCronin
So far during our discussion with Flowserve they did not mention about the need of magnetic strainer upstream of the pump.
FYI, we just have performed a...
@LittleInch
Yeah, the axial movement corresponds to the suction pressure of the pump, in this case - the Cooler Condenser 1 pressure. We put a pressure gauge in the suction of the pump and so far it does not fluctuate too much. It stays on 430 kPag. However, when the pump running, we often see...
@LittleInch
Hi LittleInch,
Thank you for your response. Does it mean that "thrust balanced" system is the culprit of this failure? Based on the video, it seems that the containment shell does not move when the thrust balance was activated.
If the internal rotor scratched the containment...
@TugboatEng
Hi, attached below are the bill of materials of the pump
I have also attached below the working principle of the magnetic drive pump (YouTube video):
Link
I agree with you, there's a leak inside the outer magnet and the blue-paint lining has completely eroded. The liquid being...
Hi Pierre,
The process is continuous. Two pumps with one as standby pump. Attached below is the process flow diagram of the system.
Pump tag number are 12P007A/B. The pump has duty to pump nitric acid condensate from 12E007 to 12C003 column. They are equipped with kickback line for minimum...
Hi Pierre,
We already checked with the vendor various times. By design this pump is capable to pump nitric acid 40%. We also have reported the failure of March 2021 and their response was due to a manufacturing defect. However, a manufacturing defect should not be the root cause because the...
Here are the summary of the failures. The yellow-coloured texts are the failures that happen when the pumps were still C3 type, while the green-coloured are failures of C4 pumps.
Hi everyone,
We have experienced weak acid pump failure (again). This pump type is magnetic drive pump (Innomag C4 3x1.5x10) The fluid pumped is nitric acid 40% with temperature of 55 degC and differential head of 1700 kPag. This is the assembly of the pump:
The start up went well however we...