LiitleInch,
Same contractor was involved in the fabrication of the original vessel. Old vessel was designed by a design firm with whom we doesn't have any contact with now. Contractor only has that drawing available. Also what's the problem in replicating the old design if everything else...
GD2, This new vessel is just a replicate of the old vessel, nothing's changed, contractor made this vessel same as the previous one. Also I don't have any data for the old vessel.
Edstainless, i already mentioned that a maintenance activity was done on the PRV while this machine was running. The PRS is in another plant, from there they have this one line that goes to this vessel in different plant. We're thinking the maintenance person might've opened the bypass for more...
Guys, I've attached the drawing file for the vessel, we dismantled the shell and found that the top side shell also got bulged inward but not more than the bottom one. PRS is set for 2.5 bar. You're saying it's too thin, but the old one worked for almost 7 years and the new one lasted for 6...
Update on my problem.
We did a little investigation and found out that a maintenance activity was done on the steam PRS at the same time as the vessel got damaged. Fitter wouldn't admit it, but he might've opened the bypass valve while working on the PRV and pressure might've gone up. Thanks for...
LittleInch, Shell dimensions are 1200 mm ID x 3000 mm Height x 5 mm thick SS 304 material with circumferential weld at middle. Top jacket height is 1180 mm, bottom jacket height is 1280 mm. Jacket is 8 mm thick MS plate. Top jacket starts at 260 mm from top. Length between two jackets is 200 mm...
Little Inche, jacket isn't spiral, it's just a CS cylindrical shell outside the SS shell, but to allow the steam to pass in a spiral manner throughout the periphery of the shell there are this flat strips of metal stitch welded in a spiral manner around the shell.
jt1234,how do you calculate the allowable external pressure for a vessel that has spiral baffles as this. What length do you take as unsupported length? I calculated without considering the spiral baffles and it got me around 1 bar. But the vessel worked well more than 3 months before suddenly...
Edstainless, two times the bulge happened at the bottom jacket where the condensate drains, also i forgot to mention there is a blower that sucks the volatile gases out through the inside of shell. The bottom cone portion is open to atmosphere and i don't think it got clogged...
EdStainless, condensate is passed from bottom of the jacket through two 1" condensate lines to a 2" line to ball float trap. According to the operator, it run smoothly for hours before it got...
We have a jacket heated agitated thin film dryer in our plant . 6 months ago it bulged on the inside. We fabricated a new vessel and after running for 6 months, it again got damaged by bulging on the inside on 6 locations like a flower. What might be the reason for this? This vessel is empty on...
NotecA, Thanks for your response.
I didn't measure vibration on motor casing, that 3 mm/s vibration is at pump side bearing housing, after replacing the old motor with new one.
I measured in all three directions, but horizontal one was higher at pump feet.
We tightened the hold down bolts and...
IR stuff, we never did any repair on motor/motor bearing, we found that the bearing balls were damaged in pump side bearing housing, so we replaced the entire bearing housing, seal and installed a new motor after finding the old motor also vibrating more.
Little Inch, we fixed the issue by tightening the alignment bolts horizontally. Now the vibration at motor feet reduced to about 2.5 mm/s. But what i don't understand is what is causing the vibration here? Like if i have a new motor shouldn't it be vibrating less whether it is fixed in place or not?
Where i work, there are two pumps(one standby)(30 kw,2955 rpm) that circulates thermic fluid. Our fitters observed heavy noise and vibration from one of them. After checking they found that the bearing balls were damaged. They did a trial check on empty motor and found it was also...
Sorry if this question is basic. I'm reading Pressure vessel design manual by dennis moss and in "chapter 6: related equipment" he used LMTD to calculate the heat load/heat required, but shouldn't actual temperature difference be used which gives the actual heat energy to be given to the process...
@mk3223 I don't have the P&ID for that only general arrangement drawing. Is it possible that the vessel is first designed for internal pressure of 1 barg and later they considered the vaccume condition and for a vessel of this size(2910mm dia and 5000mm height) it gave them more thickness than...
