Technical knowledge for piping materials

All knowledge pages in English

Technical reference pages in English – dimension tables and standards guides, maintained by our team:

• Flange standards explained: EN 1092-1, DN, PN, types & sealing faces – the flange hub: DN vs PN, old DIN numbers mapped to today's EN 1092-1 type numbers, and the sealing face forms A–H with roughness values.
• Flange dimensions PN 6 to PN 40 to EN 1092-1 – bolt circles, bolt holes, raised faces, pipe ODs and bolt sizes for DN 10 to DN 800, one table per pressure rating.
• Welding neck flange type 11: dimensions to EN 1092-1 – plate thickness, height, hub diameter and wall thickness by DN and PN, DN 10 to DN 800, with a dimensioned drawing and ordering example.
• Blind flange type 05: dimensions to EN 1092-1 – plate thickness and weights by DN and PN, DN 10 to DN 800, with a dimensioned drawing and ordering example.
• Plate flange type 01: dimensions to EN 1092-1 – bore B1, plate thickness and weights by DN and PN, DN 10 to DN 800, with a dimensioned drawing and ordering example.
• Threaded flange type 13: dimensions to EN 1092-1 – thread Rp to ISO 7-1, plate thickness, height and hub diameter by DN and PN, DN 10 to DN 150, with a dimensioned drawing and ordering example.
• Loose flanges type 02 and 04: dimensions to EN 1092-1 – the two-piece loose flange systems with plain collar 32 and welding neck collar 34, bore, collar thickness and weights per part, with dimensioned pairing drawings.
• ASME B16.5 flange dimensions: Class 150 to Class 2500 – bolt circle W, outside diameter O, raised-face diameter R, hole pattern Z × I, pipe OD and stud size, one table per pressure class, nominal sizes 1/2" to 24".
• Flange types international: ASME styles and their EN 1092-1 equivalents – weld neck, slip-on, threaded, socket weld, lap joint and blind mapped to EN types 11, 01, 13, 02/04 and 05, with facing codes and a DIN ↔ ASTM material cross-reference.
• EN 1092-1 vs ASME B16.5: flange standards compared – DN vs NPS, PN vs Class, dimensional comparison PN 16 vs Class 150 and why an adapter is needed between the two standards worlds.
• Flange connections and installation: the system of flange, gasket and bolt – sealing principle via bolt preload, installation sequence with cross-pattern tightening in stages, typical failure modes and inspection.
• Flat gaskets explained: types, materials, selection, installation – the gasket hub: how surface pressure seals a joint, the soft/semi-metallic/metallic gasket families, dimension standards EN 1514-1, DIN 2690 and ASME B16.20/21, and selection and installation criteria.
• Graphite gaskets explained: construction, service limits, resistance – laminate construction with a stainless steel insert, oxidation limit instead of melting point, chemical resistance and typical properties.
• Spiral-wound, camprofile and RTJ gaskets explained – construction and colour-code marking of spiral-wound gaskets to ASME B16.20, camprofile and metal-jacketed gaskets, ring-joint gaskets R/RX/BX to API 6A.
• Gasket installation and bolting: how the joint stays sealed – the proven 7-step installation sequence, bolt preload and lubrication (never the gasket), cross-pattern tightening in stages, and typical failure patterns with root causes.
• Flat gaskets to EN 1514-1: dimension table form IBC – inside/outside diameter d1/d2 by pressure rating, form IBC, DN 10 to DN 500, PN 2.5 to PN 40, verified against the manufacturer's dimension table.
• Flat gaskets to DIN 2690 (withdrawn): dimension table for existing plant – complete dimension table DN 4 to DN 1400, PN 6 to PN 40, verified against the manufacturer's table, for identification and maintenance of existing plant.
• Malleable iron fittings to EN 10242 – standards, whiteheart malleable cast iron, threads R/Rp to EN 10226-1, sealing, finishes and GF type numbers.
• Inspection documents to EN 10204 – certificate types 2.1, 2.2, 3.1 and 3.2, the old "3.1B", plausibility checks and forgery warning signs.
• About this knowledge: how our content is created and maintained – where the figures come from, how we check them against the standards, and why every page shows when its content last changed.
• Steel tees – dimension finder – EN 10253-2: centre-to-end dimensions F and G, pressure factor type A/B, limit deviations and roundness per welding end, with dimensioned drawings.
• Stainless steel tees – dimension finder – EN 10253-4: centre-to-end dimensions F and G, pressure factor type A/B, limit deviations and roundness per welding end, with dimensioned drawings.
• Steel reducers – dimension finder – EN 10253-2: overall length L, pressure factor to Annex C, limit deviations per welding end, concentric and eccentric, with dimensioned drawings.
• Stainless steel reducers – dimension finder – EN 10253-4: overall length L, pressure factor to Annex C, limit deviations per welding end, concentric and eccentric, with dimensioned drawings.
• Steel caps – dimension finder – EN 10253-2: outside diameter, wall thickness, overall height K, pressure factor and limit deviations, with dimensioned drawing for every size.
• Stainless steel caps and dished ends – dimension finder – EN 10253-4: caps and dished ends, overall height K, pressure factor and limit deviations, with dimensioned drawing for every size.
• Steel elbows – dimension finder – EN 10253-2: dimensioned drawing, dimension tables and limit deviations for every size, designs 2D/3D/5D, type A/B.
• Stainless steel elbows – dimension finder – EN 10253-4: dimensioned drawing, dimension tables and limit deviations for every size, designs 2D/3D/5D, type A/B.
• Steel pipes explained: EN 10216/10217, seamless or welded, test categories TC1/TC2 – how a pipe is designated (EN 10220), seamless or welded, the standard families EN 10216/10217 with the old DIN numbers, test categories TR/TC, materials from P235GH to P91, boiler tubes, threaded pipes to EN 10255, pipe vs tube and the EN/NPS dimension systems – with our stock programme.
• Materials compared: DIN, EN designations and ASTM by product form – material numbers and EN steel names with the old DIN designations, the ASTM chain per product form (pipe, fitting, forging/flange, cast steel), cast materials to EN 1561/1563, stainless steels EN ↔ AISI ↔ UNS, brass and bronze – orientation, not equivalence.
• Standards in piping: DIN, EN, ISO – and what became of the old DIN numbers – the three levels DIN, CEN/EN and ISO, what the prefixes mean, and the look-up table old DIN number → current EN standard for pipes, fittings, flanges, gaskets, threads, valves and inspection documents – with the national DIN standards that remain in force.
• Tolerances and limit deviations: why they exist and how to read them – nominal size, limit deviation, limit sizes and tolerance told apart, how a limit gets into a standard (the three-part rule for the outside diameter), the thirteen ways a standard sets a limit, why "no limit" means three different things, and what all this means at goods inward.
• Tees explained: EN 10253-2/-4 and DIN 2615, equal and reducing, selection – what a butt-welding tee is, equal and reducing designs, from DIN 2615 to EN 10253, the six words that get mixed up (drawn, necked, welded, type, equal, X), centre-to-end dimensions F and G, tolerances and EN versus ASME B16.9.
• Reducers explained: concentric or eccentric, FOT/FOB and standards – concentric and eccentric reducers, flat side on top (FOT) or on bottom (FOB), why the transition is conical, from DIN 2616 to EN 10253-2/-4 – and what part 1 and part 2 of DIN 2616 really contained –, tolerances and EN versus ASME B16.9.
• Elbow basics: designs 2D/3D/5D, angles, type A/B and manufacture – the material-independent part of elbow knowledge – the four parts of EN 10253, pressure factor X and the difference type A / type B, bend radii 2D/3D/5D with selection criteria (space, pressure loss, erosion, pigging, stresses), 45° versus 90°, seamless (S) versus welded (W), EN versus ASME B16.9. Deliberately without dimensions.
• Closing a pipe end: cap, dished end, blind flange, plug or spectacle blind – six closures side by side – permanent or reopenable, blocking during operation, size range, height, pressure, material and cost – plus the words that get mixed up on the market and what the standard deliberately leaves open.
• Dished ends and caps: torispherical heads to DIN 28011 and caps to DIN 2617 – geometry of crown, knuckle and straight flange, the torispherical heads we carry with dimensions and weights, the semi-ellipsoidal head to DIN 28013, the cap to DIN 2617 / EN 10253 as a welded pipe closure, why a fire bowl is not a dished end and what an enquiry needs.
• Test methods explained: destructive, non-destructive – and how much is tested – destructive tests on specimens versus non-destructive testing on the component, the six NDT methods VT, PT, MT, UT, RT and ET compared, dye penetrant in practice, selection rules of thumb, leak testing and why the extent of testing is set by the standard and the order.
• Stainless steel threaded fittings: threads, standards and why lengths vary – the thread is standardised and interchangeable across manufacturers, the fitting body only partly (ISO 4144, not EN 10241), the manufacturing methods behind differing lengths and weights, V2A and V4A as trade names, “light/medium/heavy” as loose terms, ASME B16.11 and NPT, and eight common mix-ups.
• Copper tubes to EN 1057: tempers, dimensions and applications – what EN 1057 regulates, the three tempers R220 / R250 / R290 in coils and straight lengths, reading the marking, the dimension table from 6 × 1 to 108 × 2.5 mm with inside diameter, weight, water content and availability, the coated and pre-insulated system variants and how copper tube is joined.
• Boiler tubes – dimension finder – Seamless hot finished steel tubes for elevated temperatures to EN 10216-2: Zickwolff dimension overview with outside diameter, wall thickness, weight per metre and the limit deviations for every dimension – with dimension finder.
• Seamless stainless steel tubes – dimension finder – Seamless tubes of stainless steels to EN 10216-5, cold and hot finished: Zickwolff dimension overview with outside diameter, wall thickness, weight per metre and the limit deviations for every dimension – with dimension finder.
• Welded steel tubes – dimension finder – Welded steel tubes for pressure purposes at room temperature to EN 10217-1: Zickwolff dimension overview with outside diameter, wall thickness, weight per metre and the limit deviations for every dimension – with dimension finder.
• Welded stainless steel tubes – dimension finder – Welded tubes of stainless steels to EN 10217-7: Zickwolff dimension overview with outside diameter, wall thickness, weight per metre and the limit deviations for every dimension – with dimension finder.
• Precision steel tubes – dimension finder – Seamless cold drawn precision steel tubes for hydraulic and pneumatic pressure lines to EN 10305-4: Zickwolff dimension overview with outside diameter, wall thickness, weight per metre and limit deviations – with dimension finder.
• Standards in comparison – what changed between editions – Per component: which dimensional statements changed between editions of EN 10253, EN 10216, EN 10217, EN 10305-4 and EN 10088-1 – with the source and the editions we cover.
• Rules of thumb from practice – checked – Class 150 is not 150 psi and DN 50 is not 50 mm – common rules of thumb checked against standards and practice.

More English pages are being added – the full knowledge base is available in German (121 pages).

Otto Zickwolff GmbH, Saarbrücken – long-established German piping material wholesaler. All information without guarantee; the current standard texts and manufacturers’ technical documentation always prevail.