Flange & Fitting Index
Standard sizes & descriptions for the connections used in dry-bulk handling. Tri-Clamp (ISO 2852), ASME flanges, Jacob ducting, DN⇄inch and pipe vs tube.
Standard sizes & descriptions for the connections used in dry-bulk handling. Tri-Clamp (ISO 2852), ASME flanges, Jacob ducting, DN⇄inch and pipe vs tube.
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 | 25.0 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. |
Reference only. Confirm exact dimensions against the governing standard (ASME B16.5 / B16.47, ISO 2852, ASME BPE, manufacturer data) and the gasket/seal for your duty.