KoTaZA,
You keep giving more clues, so I am inclined to respond a bit further.
I am not trying to belabor this point but let me try to approach it differently. "explicitly stated in the SANS 347 that all things falling under SEP are not covered by the regulation and only requires 'best practices' to be used" I do not feel this statement excludes anything SEP from regulation, but it is telling you that you cannot use SANS 347 when evaluating the design. It also tells you, that usage, designated as SEP, does indeed need to be engineered. Now what the administrative body enforcing SANS 347 and what your company considers SEP to mean seems to be where you are running into your current frustrations.
I also appreciate your petro-chem background and understand it must be frustrating going from what is typically a highly regulated industry to one where "just make sure it doesn't blow up" is your only guidance. I have been in your shoes involving upstream oil and gas processing. An example would be where you are given a Chinese pump, a Swedish separator and a Canadian reactor and a pile of pipe and fittings, all fabricated per their own country's codes and regs and your management says, create a design to hook them up and make them work. You made the statement 90% of the design requires it and only 10% falls under SEP and it now sounds like you are working under the opposite ratio but to me, this is where your job can be challenging, educational and in my opinion one of the main reason our profession exists in the first place but can be very frustrating at the same time.
In reading the progression of these posts, it appears you started where most of us would start when given a design task. The question starts with something akin to "Who is the overall authority regarding mining and processing in SA and what standards/codes do they point to as design guidance?" followed by "What are my companies standards and guidelines?" Correct me if I am mistaken but I feel what you are communicating is that both the SA regulators and your company are pointing to SANS 347 and telling you that as long as that standard is meet, there are no additional guidance or standards that need to be meet and the question being posed to this forum is "What standards are typically used in the SA mining industry for designs that fall outside of SANS 347 or are designated SEP by SANS 347" I think what LittleInch was alluding to and what I will say out right is, I don't think you are going to find any. Outside of the actual extraction from the ground, the rest is just engineering and standard engineering practices driven by specific industry best practices. I have not been directly involved with extraction and I am not a mining engineer, but I have been involved with ore processing and refinement, which it sounds like the area in which you are seeking guidance. I cannot speak to where exactly to point you because I do not know which specific industry you are in aside from mining. Without further application specific information, I will point you to some areas that might assist you.
Your company's underwriter and the standards the underwriter may have dictated to your company.
SA standards such as fire, life-safety, environmental and electrical codes. These may not directly point to information you are seeking but many time reference other codes and guidance in their application.
Guidelines and best practices from recognized industry trade groups for the specific usage and application you are working with.
Standards and specifications that were used in the fabrication of your company's existing equipment. As an example, if all your equipment was fabricates using UE standards, then it may not make much sense to apply US standard for interconnections.
Interact with local fabricators, suppliers and contractors that work with your industry to see what standards they are used to seeing and working with.
You may have to accept that part of your job will be working with equipment that will likely be fabricated under multiple different standards and trying to figure out the best standards to use so it can all work together, which could involve you having to apply multiple different standards. Best not may be the easiest for engineering but may need to be the quickest, the most economical, maintainability, interchangeability, etc. with your end result being a safe and functional design.
Lastly, I will say that there is a part of engineering that some engineers hate, which is effective communication and education of management. An example would go something like this. Your management knows that buying a pressure vessel fabricated and certified under SANS 347 is a 40% cost adder to buying and vessel from another country. When you mention that your design needs be done in accordance with a specific standard, what they are hearing is that you want to drive the cost up by 40%. Standards may cause a design to cost more money, may add complexity to the design, may make sourcing and fabrication more difficult but when properly applied may do the opposite as well. This is where some back of a napkin calculations and interactions with local fabricator, supply houses and contractors can aid you in your request to be able to apply and possible adopt standards and guidelines for your company moving forward.
