Must on-site construction be in line with the design specifications?

Construction must of course be in accordance with the construction drawings; if changes are required, the design firm must first provide revised drawings or change instructions/notifications.

It depends on whose side you’re on. If you’re the construction party, you need to build according to the plans; if you’re the project owner, you can make changes as long as it’s not a fundamental issue, but a design change is required for that.

Try to stay consistent; otherwise, you’ll bear the responsibility if something goes wrong

How can DCS and SIS instruments be changed arbitrarily? This requires process validation, after all, DCS and SIS instruments perform different functions.

The problem now is that the original drawings sent by the design institute showed that both the SIS valves and DCS valves were to have hard-sealing designs; we placed orders to purchase them accordingly. However, in the final version, the valves that did not require fire resistance features were changed to have soft-sealing designs, in an attempt to save us money. . . I think the hard-seal version has higher specifications than the soft-seal one, so that’s why it’s being used; however, the design office refuses to provide it, even after the blueprints have been prepared.

The problem now is that the original drawings sent by the design institute showed that both the SIS valves and DCS valves were to have hard-sealing designs; we placed orders to purchase them accordingly. However, in the final version, the valves that did not require fire resistance features were changed to have soft-sealing designs, in an attempt to save us money. . . I think the hard-seal version has higher specifications than the soft-seal one, so that’s why it’s being used; however, the design office refuses to provide it, even after the blueprints have been prepared.

This post was last edited by hfrs on 2018-9-4 at 10:26. Hard seals should be used in all cases; how heavy can the valve internals be? It won’t cost more than 10,000 yuan even if it’s a ton – there’s no need for that.

It must be consistent so that there is a record to rely on; at critical moments, this serves as a legal basis. Any design can be changed, but a change procedure must be followed. Different companies have different processes, I guess. However, changes cannot be made until the approval process is completed; there must still be a basis available before any changes can be implemented.

Is it the final version modified by the design institute itself? If that’s the case, the owner can refuse to acknowledge it, because unilateral changes are definitely not allowed.

This situation occurs frequently. I wonder whether the design institute informed the owner about the change to the valve seals, and whether the design specifications were revised after the hard-seal version was ordered. If it was the owner who failed to notice the changes made by the design institute, then indeed the institute may not need to alter the blueprints； If the design conditions are changed without any modification instructions, the responsibility lies with the design institute ； However, it seems that arguing won’t solve such problems. If the management of the owner side approves the hard-seal solution and it does not cause other issues related to sealing performance, it is possible not to ask the design institute to modify the blueprints; instead, an approach involving design liaison notes to endorse the owner’s approach can also be used. If the owner has sufficient technical capabilities, it is also possible to use a work order to send it to the design representative, who can then sign off to approve it. Of course, a design institute will also work, but the owner shall bear all responsibilities. So you need to consider what approach is the most reliable and safest to take!