A flocculant grade change should be visible to both purchasing and operations. A substitute may arrive under a similar name, a revised product code or a proposal to improve performance. Treat the change as a technical decision with a commercial consequence, not simply an administrative update to the supplier catalogue.
Ask exactly what has changed
Request the previous and proposed references and the reason for the change. Ask whether the difference concerns the grade, physical form, specification or only a documented naming revision. Obtain the supplier's explanation in writing. Do not assume that a new code represents identical material or that every code change necessarily means a different formulation.
Connect the proposed reference to current technical and safety information. Identify whether preparation, storage, metering or compatibility instructions differ. If the supplier cannot establish the relationship clearly, keep the material outside routine release until the question is resolved.
Review the complete chemical programme
Record upstream coagulants, the addition sequence and the operating conditions used for the existing qualification. The coagulant and PAM sequence guide explains why a polymer result cannot be separated from the surrounding treatment arrangement. A candidate evaluated under a different sequence needs an explicit review before substitution.
Discuss the proposed change with Xinqi Polymer using the actual clarifier duty. The anionic product range can identify relevant families, but matching an ionic description is not enough to establish interchangeability at the existing dose and preparation settings.
Define the necessary requalification
Choose the level of review from the actual change and the plant's risk, with the responsible technical staff. A documented naming correction may need a different review from a different physical form or treatment response. Keep the rationale in the purchasing record rather than applying an unexplained rule to every case.
For a performance change, use representative comparison data and a controlled production trial where required. Define the return-to-baseline route and avoid blending unidentified products during the evaluation. Record overflow, sediment handling and preparation behaviour alongside commercial-product consumption.
Close the change in both systems
Confirm how remaining stock of the former grade will be used or held. Record its location and avoid relabelling it as the new material. Clear stock separation helps operators interpret the transition period and prevents the purchasing history from losing the connection to earlier batches.
Update the approved product list, purchase reference and operator instructions only after acceptance. Keep the former reference in the history so old trial records remain understandable. Specify that future substitutions require the agreed notification process. This prevents a well-qualified original purchase from drifting into unreviewed supply while allowing justified improvements to be introduced through a clear, practical route.