Flange & Fitting Index
Tri-Clamp ferrule dimensions (ASME BPE / DIN 32676), flange selection and terminology, Jacob ducting, DN⇄inch and pipe vs tube.
Tri-Clamp ferrule dimensions (ASME BPE / DIN 32676), flange selection and terminology, Jacob ducting, DN⇄inch and pipe vs tube.
The inch series below is ASME BPE, published in Europe as DIN 32676 Series C. The metric series is DIN 32676 Series A or B and is not interchangeable with the inch series. ISO 2852 was withdrawn on 31 July 2018 and should no longer be specified; it was metric only and never contained these inch dimensions.
Hygienic quick-connect for food / dairy / pharma. A gasket sits between two ferrules, held by a clamp. Clamps are selected by the ferrule (flange) OD, not the tube sizethe flange is roughly ½″ larger than the tube, which is the most common sizing mix-up.
| Nominal (tube) | Tube OD | Ferrule / clamp OD |
|---|---|---|
| ½″ & ¾″ | 12.7 / 19.05 mm | 25.4 mm † |
| 1″ & 1½″ | 25.4 / 38.1 mm | 50.5 mm |
| 2″ | 50.8 mm | 64.0 mm |
| 2½″ | 63.5 mm | 77.5 mm |
| 3″ | 76.2 mm | 91.0 mm |
| 4″ | 101.6 mm | 119.0 mm |
| 6″ | 152.4 mm | 167 mm |
| 8″ | 203.2 mm | 217.7 mm |
1″ & 1½″ share a 50.5 mm flange. Gasket material (EPDM / silicone / FKM / PTFE) is chosen for the product & temperature.
Bolted flanges rated by pressure Class; flange OD, bolt circle & bolt count are fixed by size + class. B16.5 covers ½″–24″; B16.47 (Series A/B) covers 26″ and larger.
| Face | Use |
|---|---|
| Flat Face (FF) | Cast-iron / low pressure; full-face gasket. |
| Raised Face (RF) | Most common; ring or full-face gasket on a raised seat. |
| Ring-Type Joint (RTJ) | High pressure / temperature; metal ring gasket in a groove. |
Specify size + class + face + flange type (and bore/schedule for weld-neck).
Push-together pipework joined by a pull-ring or clamp band with a lip seal: common on pneumatic conveying, extraction & dust collection. Sized by nominal outside diameter, quoted as DN (mm). Sizes below are the standard family; pick the nominal you need and GQI confirms the exact figure against the duty.
| Band | Nominal size (DN) | Typical use |
|---|---|---|
| Small | DN60 – DN150 | Branch lines, extraction take-offs, small transfer duty. Pull-ring or clamp band; quick teardown for cleaning. |
| Medium | DN160 – DN400 | The common conveying and extraction range. Clamp band with a lip seal. |
| Large | DN450 – DN1600 | Extraction and dust-collection mains, silo venting. Heavier gauge and support design become part of the specification. |
| Specify alongside the size | Options | Why it matters |
|---|---|---|
| Connection type | Pull-ring · clamp band | Pull-ring suits frequent teardown; clamp band suits larger diameters and higher loading. |
| Pull-ring / band material | Galvanized · stainless | Galvanized for dry, non-product-contact duty; stainless for washdown, food and corrosive atmospheres. |
| Seal material | NBR · silicone · food-grade · metal-detectable | NBR is the general-purpose default. Silicone widens the temperature range. Food-grade is a compliance requirement in food and pharma duty; metal-detectable lets a fragment be caught downstream rather than reaching the product. |
| Conductive / earthed execution | Required in a dust-hazard area | Ungrounded ducting can accumulate static. See the Combustible Dust & ATEX reference. |
Nominal sizes are given as a family rather than exact bores: enough to select from, not a substitute for the manufacturer's dimension sheet. Confirm gauge (wall), seal material and connection type with GQI for the duty and any ATEX requirement.
| DN | Inch | DN | Inch | DN | Inch |
|---|---|---|---|---|---|
| DN15 | ½″ | DN50 | 2″ | DN150 | 6″ |
| DN20 | ¾″ | DN65 | 2½″ | DN200 | 8″ |
| DN25 | 1″ | DN80 | 3″ | DN250 | 10″ |
| DN32 | 1¼″ | DN100 | 4″ | DN300 | 12″ |
| DN40 | 1½″ | DN125 | 5″ | DN350 | 14″ |
DN ⇄ NPS is a naming convention, not an exact metric size; actual bore depends on schedule/wall.
| Pipe | Tube | |
|---|---|---|
| Sized by | Nominal Pipe Size (NPS) + schedule: a nominal name, not the true OD (below ~14″). | Actual outside diameter (OD) + wall (or gauge). |
| Wall | Schedule (Sch 5/10/40/80…) sets wall thickness. | Specified wall / gauge; tighter tolerances. |
| Typical use | Process piping, structural, higher pressure. | Sanitary lines, instrumentation, heat exchange, precise fit. |
| Connections | Threaded, butt-weld, ASME flanges. | Tri-Clamp, compression, OD butt-weld. |
† The 1/2 in and 3/4 in ferrule OD is published as 25.4 mm (1.000 in) by DIN 32676 Series C, which this table reproduces exactly at every other size. One source gives 24.99 mm. GQI publishes 25.4 mm at about 80% confidence; ASME BPE Table DT-3 was not read directly. The difference is immaterial on an elastomer-gasketed clamped joint.
Reference only. Confirm exact dimensions against the governing standard (ASME B16.5 / B16.47, ASME BPE, DIN 32676, manufacturer data) and the gasket/seal for your duty.
Sized on DIN 11850 tube. Not interchangeable with the inch series above or with Series B.
| Size | Tube OD (mm) | Ferrule / clamp OD (mm) |
|---|---|---|
| DN8 | 10 | 25.0 * |
| DN10 | 13 | 34.0 |
| DN15 | 19 | 34.0 |
| DN20 | 23 | 34.0 |
| DN25 | 29 | 50.5 |
| DN32 | 35 | 50.5 |
| DN40 | 41 | 50.5 |
| DN50 | 53 | 64.0 |
| DN65 | 70 | 91.0 |
| DN80 | 85 | 106.0 |
| DN100 | 104 | 119.0 |
| DN125 | 129 | 155.0 |
| DN150 | 154 | 183.0 |
| DN200 | 204 | 233.5 |
* value carried by a single source. Confirm against DIN 32676 or manufacturer data before ordering.
Sized on ISO 2037 / EN 10357 tube. Not interchangeable with the inch series above or with Series A.
| Size | Tube OD (mm) | Ferrule / clamp OD (mm) |
|---|---|---|
| DN8 | 13.5 | 25.0 * |
| DN10 | 17.2 | 25.0 * |
| DN15 | 21.3 | – |
| DN20 | 26.9 | 50.5 |
| DN25 | 33.7 | 50.5 |
| DN32 | 42.4 | 64.0 |
| DN40 | 48.3 | 64.0 |
| DN50 | 60.3 | 77.5 |
| DN65 | 76.1 | 91.0 |
| DN80 | 88.9 | 106.0 |
| DN100 | 114.3 | 130.0 |
| DN125 | 139.7 | 155.0 |
| DN150 | 168.3 | 183.0 |
| DN200 | 219.1 | 233.5 |
* value carried by a single source. Confirm against DIN 32676 or manufacturer data before ordering.
DN in the pipe table is a nominal pipe name. DN in a sanitary clamp is a tube size under DIN 32676. They are different systems that share a prefix, and reading one across into the other orders a part that does not mate.
| Metric size | Read across from the pipe table | DIN 32676 Series A | DIN 32676 Series B | Result |
|---|---|---|---|---|
| DN25 | 50.5 | 50.5 | 50.5 | none at this size |
| DN40 | 50.5 | 50.5 | 64.0 | Series B wrong by 13.5 mm |
| DN50 | 64.0 | 64.0 | 77.5 | Series B wrong by 13.5 mm |
| DN65 | 77.5 | 91.0 | 91.0 | wrong under BOTH series by 13.5 mm |
| DN80 | 91.0 | 106.0 | 106.0 | wrong under BOTH series by 15 mm |
| DN100 | 119.0 | 119.0 | 130.0 | Series B wrong by 11 mm |
Tri-Clamp ferrule dimensions to ASME BPE and DIN 32676, flange selection and terminology, modular ducting, DN-to-inch equivalents, and the pipe-versus-tube distinction. Values are nominal standard dimensions. Before ordering, verify the mating part's actual standard and gasket, since visually similar fittings from different standards do not always interchange.