I have a weak question
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I would like to ask all colleagues in the maritime industry: must the \"Instrument Specification\" document in the final construction drawing version issued by the design institute be modified according to the owner’s ordering requirements? For one of our company’s projects, control valves and orifice plate flow meters were purchased in accordance with the \"Instrument Specification Sheet\" provided by the design institute. However, the instruments actually ordered had slight differences from the data specified in the sheet, although the design institute approved of these differences. After our company sent the ordering specifications back to the design institute, the final blueprint produced by the institute was still based on the data sheet from before the order was placed. Does this meet the requirements of the construction drawings?
The final instrument specification sheet should match the actual specifications to facilitate future maintenance.
It’s okay if there’s inconsistency; different calculation software can produce varying results, and of course the manufacturer trusts their own results.
In situations like the one you mentioned, here we need the client’s signature for approval; the design requirements cannot be changed arbitrarily. I think it’s mainly because the designers are too lazy to make the changes.
It’s best to include a change note on the blueprint. However, for instruments such as control valves and orifice plates, it’s not a big deal if no change description is provided. The things designed aren’t very accurate; they’re even unusable. In some cases, it is necessary to modify them or select new models for procurement based on the actual circumstances.
The control valves and throttling devices are to be based on the manufacturer’s final calculations; the design institute may choose to keep them as they are or make changes, but I think it’s better to persuade the design institute to make the changes for the sake of easier maintenance in the future. Because the design documents are well preserved, things like calculation sheets become unavailable after unpacking inspections and construction; it’s impossible to go through all the handover documents in detail. If the design institute insists on not making changes, then it is necessary to pay attention to collecting and preserving the manufacturer’s calculation documents.
It is better to change it to a unified format for easier maintenance later on.
Design institutes focus on generic design, rather than serving specific valve manufacturers or throttle element producers. If you can persuade the design institute to make changes, that’s great; it’s also fine if they don’t make any changes.
Hello, I am a designer. First, to answer your question: it is acceptable to not make any modifications, as this meets the construction requirements; there is no problem with that. Secondly, generally speaking, design institutes will not modify a design just because someone specifies a particular model of product (except when the client insists on it before submitting the drawings), as they would be held responsible if there are issues with the blueprints. At least the designers are aware of the parameters specified in the original specifications. As for any deviations from the requirements ordered by your company, the fact that the design institute accepts those deviations does not mean it takes responsibility for them. In short, everything that a design institute draws up in plans needs to be treated with caution. It’s not hard to understand if you put yourself in their shoes
Thank you all for your answers. However, there is another issue: aren’t the as-built drawings required to match the actual situation exactly? In the as-built drawings, do these things need to be modified?
If it’s a mature process, the design institute often relies on standard templates when working, so they don’t go into as much detail; it’s normal for changes to occur. In your case, it’s obvious that the design institute either doesn’t want to make the changes or has forgotten to do so. It’s not a big issue – just inform the client and ensure that the maintenance staff are aware of it