What to check before ordering replacement PHE plates and gaskets for a turnaround

Autumn turnaround calendars are filling again. Refinery and utility outages in Brazil and Europe, plus plate-and-gasket tenders like NHPC's recent GeM buy for a GEA/Kelvion-make unit, all point to the same bottleneck: spare packs ordered too late, or ordered with incomplete data. This checklist is for planners and buyers who need plates and gaskets on the pad before the exchanger is opened — not two weeks after.

Compabloc is an Alfa Laval trademark. Where welded blocs appear below, say Compabloc-style / alternative. For gasketed frames, treat OEM model strings as compatibility targets, not affiliation.

Start from the nameplate and the last open-up report

Photograph the nameplate and one representative plate (both sides) before anyone strips the pack. Capture:

1. OEM model / type string and serial.
2. Plate material and thickness (often on the plate stamp, not only the nameplate).
3. Approximate plate count and which positions are start, channel, and end plates if your OEM uses that scheme.
4. Gasket compound and fixing (clip-on / slit-in / glued) from the last BOM or storeroom label.
5. Design pressure / temperature and the fluids on each side.

If the last open-up report mentions warpage, chloride staining, or repeated gasket blow-outs at one pass, put that in the RFQ notes. Vendors quote differently for a clean swap versus a known corrosion case.

RFQ fields that actually change price and lead time

A usable spares RFQ is boring and complete:

• Plate model (as stamped), material, thickness, and quantity by plate code if known.
• Gasket compound, fixing style, and whether gaskets ship fitted or loose.
• Trade term and destination (port or plant).
• Need for material certificates, dimensional inspection, and photos of first-article plates.
• Target delivery date tied to the turnaround gate, plus a late-delivery consequence you can live with.
• Whether the existing frame stays (almost always yes for gasketed PHE spares).

Do not ask a second source to "match the OEM part number" as the only acceptance criterion. Ask for dimensional interchangeability in the existing frame, stated materials, and inspection evidence. ShineHeat's pre-selection notes for buyers live here: pre-selection.

Lead-time realism for autumn outages

Plate pressing and gasket moulding are capacity-constrained when half the industry turns over at once. Build buffer:

• Trial packs (10–20 plates) validate fit before a full 200–400 plate set ships.
• Dual-source critical compounds (EPDM vs NBR vs FKM) only when chemistry allows — never mix compounds in one pack without engineering sign-off.
• Confirm slit-in gaskets are fitted before shipment if your craft time on site is short.

Public tenders that specify OEM-make models (for example a GEA/Kelvion-make plate count on GeM) are a reminder that buyers already think in model strings. Answer in model-compatible language, with a clear non-OEM / compatible disclaimer.

Turnaround-week failure modes to pre-empt

• Wrong thickness (0.4 vs 0.5 vs 0.6 mm) that "almost" hangs in the frame.
• Gasket fixing mismatch (glued ordered when the plant only stocks slit-in tools).
• Missing end / transition plates in a mixed A/B count.
• Certificates arriving after customs clearance holds the crate.

Put first-article photos and a packing list template in the PO. For welded Compabloc-style blocs the spare logic differs (cover seals and cassette work, not elastomer plate gaskets) — keep those RFQs on a separate form so storerooms do not issue the wrong kit.

Bottom line

Order against physics, nameplate data, and the outage gate. Treat OEM model codes as compatibility anchors. Leave fantasy cross-reference spreadsheets out of the critical path.

Photo pack to attach to every RFQ

Vendors waste a day asking for pictures you already have on a phone. Bundle:

• Nameplate, straight-on and readable.
• Full frame from the operator side and the opposite side.
• One loose plate (both faces) with a ruler in frame.
• Close-up of gasket groove or clip if the pack is open.
• Any existing arrangement drawing or last purchase-order line items.

Label files with plant tag and date. That pack plus the checklist above is usually enough for a compatible-plate quote without a site visit.

When the OEM model string is incomplete

Some nameplates only show a frame family. Then count plates and note start, channel, and end codes stamped on the plates. Measure port diameter and centre distances if craft can do it safely. Ask the incumbent OEM for a GA under NDA if you still buy frames from them, even when plates will come from a second source.

Incomplete data creates provisional quotes that change after first-article inspection. Budget one revision cycle in the turnaround plan instead of pretending the first number is final.

Compatible vs OEM — wording that keeps legal calm

State in the PO: compatible / replacement plates and gaskets for model [X], non-OEM, not affiliated with the original manufacturer. Buyers already use OEM model strings in public tenders; clarity beats vague equivalent language that nobody can inspect against.