Gasket Size Chart by Flange DN & PN

Reverse lookup: flange DN × PN → gasket

The DN axis is the ten sizes in our range (DN15–DN300); the PN axis is the two grades in our range (PN10 / PN16, PN16 by default). Both grades are shown side by side: across DN15–DN200 our PN10 and PN16 gaskets are the same size and the same unit weight grade by grade (one value shown when equal), and only DN300 is split. Sizes outside our range are listed under "outside our range" below and are not extrapolated here.

Non-metallic flat gasket GB/T 9126.1 (PN series): inner × outer × thickness

Non-asbestos fibre sheet, NBR and PTFE share the same geometry (IBC type, the PN-series dimensions equivalent to EN 1514-1); 2.0 mm is the standard supplied thickness and 0.8–3.0 mm can be specified. The last column gives the product code of the catalogue line for that DN (row-level provenance) and links to the sizes available under that standard.

Spiral wound gasket GB/T 4622.1 (PN series): winding inner × outer × thickness

4.5 mm winding and 3.0 mm rings are the standard supplied thicknesses; the outer ring OD column gives the PN10 / PN16 values side by side — identical across DN15–DN200 in our range, split only at DN300. 304 + graphite is the standard combination; 316L and PTFE fillers are quoted per order. The last column gives the product code of the catalogue line for that DN (row-level provenance) and links to the sizes available.

PN vs Class: nominal comparison and a no-interchange warning

PN (GB/T 1048) is the metric nominal-pressure designation, expressed in bar; Class (ASME B16.5) is the US pound-class designation and is dimensionless. The two columns below are a plain unit conversion of each designation's own basis value, plus the pairings seen in practice — this is not a conversion table and must not be used to interchange parts.

Non-metallic flat gaskets = ring area × thickness × material density (the library records weight_src=calc, so the formula is the stored value); spiral wound gaskets use the component method (winding at 3.3 g/cm³, inner ring at 7.93 g/cm³, outer ring at 7.85 g/cm³). The material densities 1.6 / 1.2 / 2.2 g/cm³ are the per-material values recorded in the library.

Cells hold the bulk weight (kg/1000 pcs); the grams per piece and the kg/1000 pcs figure are the same number. PN10 and PN16 differ only at DN300 (non-asbestos fibre 30.3 → 30.3 kg/1000 pcs). Theoretical estimates, for quoting and freight budgeting; settlement follows actual measurement.

Data basis and sources

Every dimension on this page is the specification value of a gasket SKU in our product catalogue (the same source as the non-metallic flat gasket and spiral wound gasket pages in the pipe flanges and gaskets category): non-metallic flat gaskets to GB/T 9126.1 (PN series, IBC type, the PN-series dimensions equivalent to EN 1514-1), spiral wound gaskets to GB/T 4622.1 (PN series, dimensions from the published EN 1514-2 d1–d4 values). The per-row dimension and density URLs are archived in the catalogue spec_json; unit weights are the same parameter and the same value as the catalogue (ring area × thickness × density for flat gaskets; the component method for spiral wound).

Boundary: this page reverse-looks-up our actual catalogue range — it is not a standard's front dimension table. It covers only the ten DN15–DN300 sizes in our range at PN10/PN16 and gives no extrapolated values outside that range, nor any Class-series table values. Unit weights are theoretical estimates (excluding packing and plating) and serve as a reference for quoting and freight; selection and acceptance follow the system marked on the flange and the drawing.