Greetings!
A 40" LP acid gas line (normally no flow) with 130 degC temperature is LP steam traced. Steam 4.1 barg (140 degC) is used to keep the pipe wall at 130 degC. Internal corrosion occurred die to water condensation.
Two questions:
1. During no flow condition, should the steam tracing...
I am carrying out API 579 brittle fracture assessment for CS knockout drum (KOD):
MAWP = 14.5 barg
MDMT = -16 degC
New low oper. temp = -27 deg C @ 10 barg.
Thus, CET = -27 degC.
As per assessment calculated MAT = -30 degC < CET [OK]
Basis for MAT reduction is PWHT done post-fab...
In our plant we had number of cases where spring hanger locking nuts have moved into "locked position" due to piping vibration - nuts tend to slide down. That resulted in spring hanger casing damages and temporarily increased piping loads. To minimize such occurrences I'm thinking we could...
We are revamping an LNG train and some plate and frame amine exchangers need to have some 10% extra plates added to handle additional heat duty.
Question has been asked whether this constitutes alteration and requires R stamp. We are in Middle East and there is no change to the size of the...
I feel it is safe to report that this was a case of acoustic vibration caused by vortex shedding.
Basket was damaged by vibration, upon its removal vibration and noise disappeared.
strainer opened, basket damaged, but installed properly
op parameters and all else is as before the problem started
except that the mesh was removed in the meantime
vortex shedding?
Gents,
Thanks on your responses. The flow induced vibration is creating noise of about 120 dBA, source seems to be the strainer spool. We will shortly open the strainer and look inside.
I already asked this question in thread384-356365 (apologies for cross-posting), however, no-one replied re strainer design criteria with respect to acoustic phenomena. I'm kinda hoping I'm going to have more luck here. :)
Yes, we are worried about pipe shell mode vibrations - we will employ stress measurements to calculate fatigue life. Just wanted to understand whether measured values are clearly high (requiring shutdown) or not.
We have opened the strainer, removed the basket and reinstated the piping. The high noise accompanied by low amplitude vibration is gone.
However, we have now detected another strainer basket where noise level is somewhat increased:
105 dBA, 3.36 RMS mm/s velocity, 826 Hz
Is there any...
We are experiencing a vibration / noise in a stretch of 38" piping downstream from compressor to the first heat exchanger. In this stretch of piping there is a conical strainer with fine mesh. Recently we have removed the fine mesh from the strainer perforated plate (basket). There was no noise...
Our 4" utility line has a bad leak.
Fluid: water
Pressure: 5 barg
Temperature: ambient (above 0 deg)
Pipe lenght: 800 m
Depth: 1 m, covered with 30 cm of concrete
The leak is quite bad indicating construction issue, and not corrosion. I am trying to understand capabilities of various...
It will work out, I am sure. If everything was straightforward oil companies wouldn't need engineers but just secretaries and technicians. ;-)
Cheers,
Sean
