Agreed, 1.5 times (max) the set pressure to achive pop test as recommended by API RP 576 us way to high and imagine the case with high pressure valve. I still wonder how this value has been given in API.
At the same time it is also true that 1.1 times the set pressure is also too low, normally...
Thanks Duwe6, Thanks for the answer, In most cases ( or in typical Ammonia plant environment) the design pressure of the system is the set pressure of pressure relief valve. If we go as per API576 and pop test the PSV at 1.5 times the CDSP and consider the PSV acceptable, this also implies that...
Hi all,
We have problems with the performance of relief valves on site, the valves when taken to test bench in " as received" conition for pop test , they generally do not lift on the cold diff set pressure (within the tolerance) which then reduces the next run campaign of the relief valves. AS...
We know that 304L is the best choice for nitric acid environment due to oxidation issue involved with Mo, when you buy SS304L from the market, it comes with some percentace ( close to 0.03%) of Mo in the form of impuritiy. The questions I have
1. what is the max permissible Mo that can be...
ASME section VIII specifies acceptance criterion for cold differential test pressure of relief valve which is +/- 2.5%. Can this be applied to an API valve? or API has their own set of specifications on this?
ASME section VIII specifies acceptance criterion for cold differential test pressure of relief valve which is +/- 2.5%. Can this be applied to an API valve? or API has their own set of specifications on this.
We have an exchanger in Nitric acid plant, the channel of this exvhanger is parially made in Ti Gr 2 while rest of it is made with Ti Gr 12. We have been experience corrosion in the HAZ of G 12 Titanium and would like to understand the difference between these grades in terms of corrosion...
Hi,
Recently I came across a very old WPS for welding alloy steel (ASTM A 335P22 to A 335P22). The WPS recommended use of argon back purge? Is that common to have back purge and what is the advantage of having it while welding. I am aware of back purge in stainless steel and risk of oxide...
Please refere to ASTM A 333, there are grades available within this mnaterial based on carbon content, you will find material properties for each one of them regard s
Hi,
We have a Den Exit fan installed in super phosphate plant, the impeller is made in SANICRO 28 and has a limited life due to very aggresive corrosive medium. It contains 1% Fluosilicic acid, and approx 0.2% hydrofluoric acid. Air temperature would be in the range of 40 - 55C. Can anyone...
Dear all, we had an incident of rotor seizure of syn gas compressor in ammonia plant. The compressor tripped on high vibration and came to halt very quickly, internal inspection inspection revealed that impellers and labys were all good on but inboard primay gas seal was damaged and found in...
We are replacing primary reformer tubes and its outlet pipe which is made in inconnel 800 HT is welded to existing 800 HT pigtail. I would like to know is it required to solution annealed the weld after repair and why. The existing inconel 800 HT pigtail is in service for more than 7 years and...
Hi
I understand the requirement of pressure test / hydro test on inservice equipment are derated. Can any one help, which stardards define these guidelines ?
cheers
