Can process manholes be installed according to ASME Appendix 44 design?
Thread Content
Hello everyone, I have a question for you. When designing in accordance with ASME Appendix 44 (Design of Strain-Enhanced Austenitic Stainless Steel Pressure Vessels), is it possible to include manholes? Appendix 44-2 specifies as follows: Clause (i): Except as per clause (j), the diameter of the pipe openings shall not exceed DN150; Clause (j): The diameter of the pipe opening at the center of the head shall not exceed DN200 ； Can it be understood that (i) rivers and (j) channels refer to process pipe outlets, excluding process manholes? I would appreciate it if the experienced ASME experts in this group could provide an explanation. Thank you.
According to ASME Appendix 44, a process access hole can be designed and installed if it is no larger than DN200 and is located at the center of the head. (i) and (j) mainly relate to the size of the nozzles and do not pertain to service manholes. However, relevant regulations must be strictly followed during design, and thorough strength checks must be carried out. .
Thank you for your reply. Since it is a process manhole, it can be drilled for use; it certainly can’t be DN200 – at least it should be DN400
In accordance with ASME Appendix 44, clauses (i) and (j), although there are no explicit specifications regarding the size limits of service manholes, safety considerations in design require that these manholes be larger in order to facilitate access by personnel. Therefore, if it is necessary to install process manholes of DN400 or larger size, additional reinforcement measures or design approaches may be required to ensure the overall strength and safety of the pressure vessel. It is recommended to consult an expert on ASME codes or a certified engineer to ensure compliance with all relevant regulations and safety requirements. .
Thank you for your reply. According to what you said, it is possible to install a process manhole, right?
Yes, process manholes can be installed, but attention must be paid to their dimensions and location, and appropriate reinforcement measures must be taken to ensure safety. .
If you look at the original English version, it’s clear that large openings cannot be provided. By the way, what industry are you in? From what I understand, industries that use this technology don’t have manholes.