Measure the fill stage
Use cycle logs to distinguish actual liquid entry time from time spent waiting for permission or depressurization. Check whether the slow fill affects both vessels or only one. Record source-tank level and product temperature; a low head or colder liquid can explain a change without any hardware fault.
Review the inlet route
Look for an undersized connection, a partially closed valve, a fouled strainer, unexpected bends or product accumulation. Verify that the route and valve position match the approved arrangement. Also review how displaced gas leaves during filling; an unsuitable vent path can affect performance. Inspection and cleaning must follow the plant isolation procedure.
Check measurement and assumptions
A coated or misconfigured level device may report a delayed or incorrect endpoint. Compare the indicated state with a safe, approved verification method. Confirm that the product remains within the viscosity and solids range used for selection. Do not respond to a slow-fill problem merely by increasing discharge pressure.
Escalate with useful evidence
Send the supplier cycle trends, alarms, product data, source levels and the current route drawing. State what changed and when the problem began. If vacuum assistance or a pipe modification is proposed, review its complete mechanical and control implications. Correct the identified bottleneck and verify several cycles under the same conditions before judging the result.
General engineering guidance. Numerical examples are illustrative; project specifications and acceptance criteria are agreed for the actual duty.