Shaker Screen Bids: Audit API Labels, Part Identity and Fit

A screen quotation can be commercially complete yet technically ambiguous. The price, quantity and shipping term may be clear while the offer never identifies the assembled panel that will arrive. The most effective first review is therefore an identity-and-evidence audit, not a contest between mesh numbers.

Use this guide when comparing replacement offers for shale shaker screens. It addresses the purchasing record; it is not an instruction to modify, install or operate a shaker.

Start with the claim the bidder is making

Ask whether the offer is an exact replacement, an identified alternative or an unspecified panel described only by a mesh label. These are different commercial propositions. Preserve the installed shaker identity and the old panel marking as buyer inputs, then ask each bidder to complete the same fields.

This table is a proposed review workflow, not a claim that an unidentified alternative fails a particular test. A missing field means the proposal needs clarification; it does not justify inventing a favourable value.

Do not turn mesh into an API designation

Page 5 of the GN screen brochure distinguishes a single-layer mesh description from the cut-point classification of the assembled multilayer screen. Use that distinction when a supplier writes “equivalent mesh” without identifying the panel.

Keep the supplier's original wording in the comparison sheet. Record separately what the panel is called, what classification is declared and what supporting record actually covers. A manufacturer's claim that testing follows a standard is not the same as an independently verified certificate, and an API screen designation is not an API manufacturing licence.

Do not repair an ambiguous quotation by translating mesh count into an API number from an unrelated chart. Ask for the assembly identity instead. This avoids a false equivalence that can survive into the purchase order even after the technical team has changed its intended screen selection.

Keep classification, conductance and fit separate

The GN brochure's page 8 gives concrete G75F part-number examples. Their usefulness is that a reviewer can keep the classification, conductance and area on the same row as the part number. The historical table is not a current stock list and does not approve every similarly named screen.

A proposed alternative may match a separation designation yet differ in its hydraulic description or frame interface. Conversely, a matching frame does not establish an identical separation result. Require the bidder to state which aspects are claimed equivalent and which differ. Do not let a photograph of a similar panel replace that comparison.

Keep complete-machine screen area out of this panel worksheet. It describes a different equipment boundary and cannot establish the non-blank area, conductance or identity of a replacement screen. Refer complete-equipment questions to the linear-motion shaker reference.

Turn deviations into an intelligible order basis

A useful deviation register identifies the requested item, the proposed item, the stated difference, the evidence available and the person responsible for resolution. Use qualitative dispositions such as accepted for further evaluation, clarification pending or exact replacement required. These are purchasing decisions, not invented performance scores.

If supporting drawings or assembly test records are not available at enquiry, obtain a clear description of what will be provided during technical clarification. Avoid making every order-controlled document a prerequisite for an initial budget quotation. Equally, do not describe an unsupported alternative as fully interchangeable.

Before closing the technical comparison, check that the selected part identity remains the same across the quotation, proposed packing list and any agreed inspection scope. Keep uncertainty visible rather than burying it in a general compliance statement.

Submit the installed-machine and panel identification, requested designation, acceptable-alternative policy, quantity and destination in a screen RFQ. Attach the completed comparison sheet when available so the response can resolve actual deviations instead of repeating an ambiguous mesh description.