It requires minimum size of fillet welding size ( e.g. 3/8”) for typical full penetration nozzle to shell welding connection per ASME code. However , it seems no maximum limitation for the fillet size. Based on my experience , the thickness of vessel wall typically is limiting of size of it ...
Hello:
I need some instruction on how to calculate the reactive force for a pressure relief valve flowing non compressive liquid . The formula provided in API 521 seems to only apply for compressive fluid. Thank for your response.
As per the 3.8 Article 2.1 in ASME PCC-2, it requires to maintain a minimum distance of 6 in between the nozzle attachment weld and the nearest edge of the insert plate butt weld. I am wondering what is basis to select the 6” spacing, not 8 in or 4 in. It seems not to include this requirement...
Hello:
I need to clarify one thing with some experienced engineer which is not clear for me for long time. The impact of external piping load on vessel and its support from global point of view. Normal engineer practice is to conduct local stress analysis due to the impact of external nozzle...
Hello, Everyone:
It seems for me that most oil gas clients does not allow to use repad in nozzle design for pressure vessel experiencing high operating pressure & temperature or severe corrosion . Not sure what is the reason behind? Is it becasue of concern of repad to shell joint welding quality ?
Hello, gr2vessels:
Yes, We are planning to do local hydrotest on the new nozzle only after fabrication because the size of vessel and some restraints on site , it is almost impossible to do hydrotest on the whole vessel.
Thanks
Abraham
Hello:
I have been working on a large vertical vessel alteration project. The client wants to add a new 12" nozzle on existing vessel. We had a discussion about site hydrotest requirement few days ago. We will have to weld a cap internally to cover up the new nozzle and then proceed hydrotest ...
Hello:
It seems for me that it does not include 5 Gr-1/2 mo ( P5B- Gr 1 ) group material into Table UHA-32. Does it mean that 5 Gr- 1/2 mo group material not consider as high alloy materail , so the requirement as per UHA does not apply for it. Please clarify .
Thanks
Abraham Hong
I have been using ASME section III nuclear flange calculation for flange joint checking for one process piping design( design code ASME B31.#). Now someone is questioning whether or not ASME III nuclear flange calculation is accetpable for oil and gas applications . The piping sysem is not a...
We have a case with Shell Improve group where a 2” 40 sch weldolet, already welded to the 24” main pipe, has to be welded to a Sch 160 welding in thermowell . So there is misalignment on the butt welding between welding in thermowell and weldolet . My question is how to dertermin if the weld...
Hello:
We have a very hot vessel (96”) diameter pipe (800 deg F) supported by two saddles. Is there a way to determine the heat dissipation or how long the supporting steel has to be to avoid over heating Teflon sliding plate installed underneath floating saddle?
I did a research on this...
Hello, fegebush:
Thank for your response. It is fairly large diameter tank with rafters . The spacing between rafter is about 1899mm.It is also a cross brace installed in the middle of rafter. The flat plate design criteria basically is a concentrate load at various location on 1899 mm W x...
Hello:
I am running into a situation that we have to install some of operating platform support on the roof plate of one existing API 650 tank. So it is becoming a design case to apply a concentrate load at various location on flat plate. I could not find any design guideline in API 650 code...
I am currently designing a tailing lug for a pressure vessel repairing project. The client wants to replace the top portion of a vertical tower ( partial of shell and top head). The shell thickness is ½” but with 4” refractory internally installed . The removed portion will be lifted up...
Hello
I encountered a question from client which never think about before . There is a 24 in manway on a pressure vessel with fairly high design pressure. One of mechanical engineer ask me whether or not I checked the local stress for this mayway due to axial force induced by internal pressure...
Hello:
For a tank terminal project we have been working on, expansive soil were observed and some soil shrinkage & expansion will be anticipated based on Geotechnical Engineer report . I need some suggestion how to consider the expansive soil in the stress design using CAESAR II.And any good...
I need some help to clarify what is thermal treatment defined as per UHA-51 ( c ). Some SS material exempt as per UHA-51 ( d ) is not acceptable any more when thermal treatments is performed . I am wondering if PWHT or hot formed head is considered as thermal treatment.
UHA-51(d) Exemptions...
For BET type heat exchanger, the tube side floating head assembly including head , girth flange normally contacts with shell side process fluid , in another word, will experience external pressure same as internal pressure on shell side . I am working on the replacement job of BET type shell...
Hello:
Having a question about nozzle reinforcement design. It is a 4" NPS coil installed inside one pressure vessel . The coil nozzle penetration through the vessel. The vessel and internal coil are designed in accordance with ASME VIII DIv 1. Coil internal design pressure is 200% higher than...
