Engineering Tools · Flange Quick Reference
DN20 Flange Weight & Dimension Quick Reference
Weld neck WNF (GB/T 9115) and plate slip-on PLF (GB/T 9119) on one page: full dimension columns for DN20 D/K/bolt holes/thickness/sealing face, unit weight in kg or lb for carbon steel/304/316L, PN10/PN16 toggle on page (default PN16), nominal size and source fully disclosed.
DN20·PN16 (carbon steel) weld neck WNF ≈ 1.09 kg/pc, plate slip-on PLF ≈ 0.93 kg/pc; OD 105 mm, bolt circle 75 mm, 4×Φ14 mm (with M12 stud bolts), PN10/PN16 both on page.
Other Sizes
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DN20 Flange Dimension Parameters (PN16, unit mm)
Letters correspond to GB/T 9124.1/GB/T 9115 series dimension codes: D OD, K bolt circle diameter, L bolt hole diameter, n number of holes, C flange thickness, d4 raised face (RF) OD, f raised face height, H weld neck length, N1 neck OD; plate slip-on PLF has no raised face/neck columns.
Weld Neck WNF (GB/T 9115)
| OD D | 105 |
| Bolt Circle K | 75 |
| Bolt Holes n×L | 4×14 |
| Stud Size | M12 |
| Flange Thickness C | 18 |
| Raised Face OD d4 | 58 |
| Raised Face Height f | 2 |
| Weld Neck Length H | 40 |
| Neck OD N1 | 40 |
Plate Slip-On PLF (GB/T 9119)
| OD D | 105 |
| Bolt Circle K | 75 |
| Bolt Holes n×L | 4×14 |
| Stud Size | M12 |
| Flange Thickness C | 16 |
Pipe OD 26.9 / Bore 22.3 mm
Unit Weight (DN20 · PN16, kg/pc)
| Type | Carbon Steel | 304 Stainless Steel | 316L Stainless Steel |
|---|---|---|---|
| Weld Neck WNF (GB/T 9115) | 1.09 | 1.1 | 1.11 |
| Plate Slip-On PLF (GB/T 9119) | 0.93 | 0.94 | 0.95 |
Cell shows unit weight (kg/pc): WNF/PLF × carbon steel/304/316L. PN10/PN16 column values differ where applicable, calculated cell by cell; theoretical estimate, settlement subject to actual measurement.
References
- GB/T 9115-2010 Pipe Flanges – Weld Neck Steel Flanges series (National Public Service Platform for Standards Information)
- GB/T 9119-2010 Pipe Flanges – Plate Flat Steel Flanges (National Public Service Platform for Standards Information)
- EN 1092-1 PN series flange dimension/weight published tables (hsflange / marcelforged / tesco dual-source, row-by-row archived in catalog spec)
- Dimensions and weights cross-checked against 60 flange SKU spec_json in product catalog (same source as product pages)
Material Density Conversion
Table values are for carbon steel (7.85 g/cm³); other materials converted by density ratio: weight × factor.
| Material | Density (g/cm³) | Conversion Factor |
|---|---|---|
| Carbon Steel | 7.85 | ×1.000 |
| 304 Stainless Steel | 7.93 | ×1.010 |
| 316L Stainless Steel | 7.98 | ×1.017 |
Data Basis and Source Disclosure
Dimensions and unit weights are taken directly from product catalog flange SKU spec values (same source as WNF/PLF product pages under /products/pipe-flanges-and-gaskets/): dimension columns follow GB/T 9115 (weld neck) / GB/T 9119 (plate slip-on) PN series nominal sizes, whose dimensions/weights are from EN 1092-1 published tables (dual-source cross-checked from hsflange/marcelforged/tesco, row-by-row URLs archived in catalog spec); carbon steel 7.85 g/cm³ table values are catalog values, 304/316L converted by density ratio 7.93/7.98 ÷ 7.85 (estimate). Weld neck flange small-size shared rating rules follow EN 1092-1 (PN10/PN16 DN≤40 use PN40 dimension class, PN10 DN50–150 use PN16 dimension class, PN10 dedicated series from DN200), and this table matches each class.
Boundary: This table is a theoretical unit weight estimate (excluding gaskets/bolts/nuts and coating allowance), for quotation, freight and lifting budget reference; actual table values and unit weights for the same DN×PN vary with manufacturing standard version, sealing face type (RF/FF etc.) and material tolerance, trade settlement subject to actual measurement.
Corresponding standard page
Open the GB/T 9115 PN16 standard product page: sizes, materials and finishes, and ordering questions.
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FAQ
How much does a DN20 PN16 weld neck flange (WNF) weigh approximately?
Per catalog table values (carbon steel 7.85 g/cm³): DN20 PN16 weld neck WNF approx. 1.09 kg/pc, plate slip-on PLF approx. 0.93 kg/pc; 304/316L approx. ×1.010 / ×1.017. Same page can toggle PN10 for comparison (weld neck small sizes share dimensions between two ratings, weight basically same).
What is the weight difference between PN10 and PN16 flanges?
PN16 flanges have greater thickness/bolt circle and are usually heavier: for DN20, PN10 weld neck approx. 1.09 kg, PN16 approx. 1.09 kg (WNF); PN10 plate slip-on approx. 0.94 kg, PN16 approx. 0.93 kg (PLF). Weld neck flanges small sizes (DN≤150) share dimensions between two ratings so same weight; from DN200 PN10 uses dedicated dimension series.
How many bolt holes and what size for DN20 flange? What studs to use?
For PN16 class: weld neck WNF 4×Φ14 mm (bolt circle K=75 mm), plate slip-on PLF 4×Φ14 mm, both with M12 stud bolts + hex nuts (hole diameter ≈ stud diameter + 2~3 mm). See cross-reference table at page bottom for matching stud/nut dimensions and weights.
How to choose between weld neck flange (WNF) and plate slip-on flange (PLF)?
Weld neck flange has tapered hub and butt-welded connection, better load bearing and fatigue resistance, suitable for medium/high pressure, temperature fluctuation, frequent assembly piping (e.g., PN16, DN200+ process piping); plate slip-on flange is directly fillet welded on pipe end, saves material and labor, lower cost, suitable for low-pressure ambient water/gas etc. For same DN×PN, WNF is usually heavier than PLF.
What nominal size basis are these flange weights calculated on?
Table values directly use product catalog flange SKU spec values (EN 1092-1 published tables, carbon steel 7.85 g/cm³, dual-source cross-checked, row-by-row URLs archived); 304/316L converted by density ratio, all excluding gaskets/fasteners and coating. Theoretical estimate for quotation reference only, trade settlement subject to actual measurement.
What are D, K, C, d4, f in the flange dimension table?
D=flange OD, K=bolt circle diameter, C=flange thickness, d4=raised face (RF) sealing face OD, f=raised face height; bolt holes denoted as n×L (n=number of holes, L=hole diameter). See dimension parameter table at page top for DN20 specific values, toggle PN10/PN16 to compare differences (weld neck flange small sizes share dimensions between two ratings).
Related References
Weld Neck Flange (WNF) Product Category
GB/T 9115 PN10/PN16 weld neck flange catalog: DN15–DN300 × carbon steel/304/316L, with inquiry and drawing customization.
Plate Slip-On Flange (PLF) Product Category
GB/T 9119 PN10/PN16 plate slip-on flange catalog: DN15–DN300 × carbon steel/304/316L, economical choice for low-pressure piping.
M12 Stud Bolt / Threaded Rod Weight Quick Reference
Matching flange fasteners: same-size stud bolt/threaded rod weight per meter and unit weight by length class, same nominal size as flange table.
M12 Hex Nut Weight Quick Reference
Matching flange fasteners: same-size hex nut unit weight and kg per thousand pieces (GB/T 6170 nominal size).
Industrial Pipe Flanges (L3 Scenario Page)
Industrial pipe flange selection and purchasing essentials: type, pressure rating and sealing face coordination.
Disclaimer: This table is engineering estimate data for selection, quotation and freight estimation reference only, not a design basis or acceptance standard.