Regulations on pipeline design errors and ISO diagrams
Thread Content
Are there any standards that specify the maximum allowable error in pipeline design? On the piping layout diagram, the pipe connections of the two devices differ by 100 mm from the actual values. This results in the pipe needing to be extended by 100mm – is this considered a technical error? The construction error for civil engineering work seems to be around 100-200 mm as well? Regarding the ISO diagram, it can be used as a basis for material cutting during construction; however, the final section of the ISO diagram that connects to the equipment must be measured on-site. Which specification states this?
In the situation you described, if the dimensions indicated on the drawings differ by 100 mm, it is a design error. Otherwise, it is an installation error (if it falls within the error range specified by the standards) or a mistake in installation. Regarding the second question, you may refer to the provisions of 7.2.2 in the \"GB 50235-2010 Code for Construction of Industrial Metal Piping Projects\". For your reference, 7.2.2 The selection of free sections and enclosed sections should be reasonable; enclosed sections should be fabricated according to the actual installation length measured on site.
I really haven’t seen any regulations on this matter. If the deviation of the equipment nozzles on the drawing is 100 mm, it is not necessarily someone’s fault; it could be a problem with the manufacturer, as the drawing does not match the actual product ； It might be a mistake made during the design input stage. When constructing with ISO diagrams, don’t tell me that everything is completely pre-fabricated and only needs to be installed on site – there will definitely be some deviations. Even if the design is perfect, there are still errors of 100-200 mm as you mentioned in civil engineering work. Special pipes (such as lined pipes and vacuum pipes) require special attention to this issue in their design and manufacture.
As a further addition, when prefabricating ordinary metal pipes, it is necessary to reserve 2 to 3 locations for on-site welding, opting for straight sections of pipe. I’ve never seen the standard, and I don’t know how I know it. . For pipes made of other materials, such as PVC and fiberglass-reinforced plastic, some interfaces are also left unfinished for on-site installation.
For a cylindrical device, the height of the horizontal pipes connected to it differed significantly from the designed value, which was quite puzzling. The owner, supervisor, contractors, and designers all carried out on-site measurements, putting in a lot of effort, until it was finally discovered that the deviation was due to the difference between the outer diameter of the cylindrical device and that specified in the drawings.