Piping know-how
Piping glossary English–German: for German drawings, documents and sites
Working on a German site or with German isometrics, piping classes and bills of materials? This glossary gives the German equivalents of around 230 technical terms and drawing abbreviations used in piping and plant construction – as they are actually meant on site: elbow (Rohrbogen), spectacle blind (Brillensteckscheibe), socket weld (Muffenschweißverbindung), BOP and WP. Where the literal translation is misleading, a note is added.
Terms that are often mistranslated
Some English terms are routinely rendered wrongly in German, or mean something specific on a piping site. In practice, these mix-ups cost the most time:
globe valve
is a globe valve (German: Absperrventil / Durchgangsventil), not a ball valve (German: Kugelhahn).
plug valve
is a plug valve (German: Kükenhahn).
socket weld (SW)
is a socket-welded joint (German: Muffenschweißverbindung, ASME B16.11), not a branch/nozzle weld (German: Stutzennaht).
schedule (Sch)
in a piping context always means the wall thickness series to ASME B36.10, never a timetable (German: Wanddickenreihe, not Zeitplan).
jacking bolts
are bolts used to push a flanged joint apart (German: Abdrückschrauben).
invert
on isometrics refers to the inside bottom of the pipe, i.e. the elevation of the internal bottom edge (German: Rohrsohle).
filler (metal)
in welding is the consumable added to the weld (German: Zusatzwerkstoff). Only “filler plate” is a packing plate (German: Futterblech).
XS / XXS
do not consistently correspond to Schedule 80 and 160 – XS matches Sch 80 only up to NPS 8.
226 terms
| English | German | Note |
|---|---|---|
| actual cost | Istkosten | |
| adjusting screw | Stellschraube | |
| air exhaust | Luftauslass | |
| anti-corrosive | korrosionsgeschützt | |
| approximate (approx.) | ca. | |
| ball valve | Kugelhahn | |
| battery limitBL | Anlagengrenze (Battery Limit) | Interface between plant units / trades |
| bend | Rohrbiegung, gebogener Rohrbogen | elbow = fitting, bend = formed from the pipe itself |
| bevel, bevelledBE | Fase, angefast (Schweißfase) | |
| bleeder | Entleerungsventil, Ablassventil | |
| blind flange | Blindflansch | |
| boiler | Kessel, Dampferzeuger | |
| bolt | Schraube, Bolzen | |
| bore | Bohrung | |
| boss | Nabe, Ansatz | |
| both ends bevelledBBE | beidseitig angefast | |
| both ends plainPBE | beidseitig glatt | plain end = square-cut end, no bevel or thread |
| both ends threadedTBE | beidseitig mit Gewinde | |
| bottom of pipeBOP | Rohrunterkante (UK Rohr) | |
| branch | Abzweig | |
| brass | Messing | |
| bubble cap | Glocke (Glockenboden) | Column internals |
| butt weldBW | Stumpfnaht | |
| by-pass | Bypass, Umgehungsleitung | |
| carbon steelCS | C-Stahl, unlegierter Stahl | |
| cast iron | Gusseisen | |
| centre lineCL | Mittellinie | |
| centre to centreC/C | Mitte–Mitte | |
| chain operated | mit Kettenradantrieb | |
| check valve | Rückschlagarmatur, Rückschlagklappe | |
| cold spring / cold strain | Kaltvorspannung, kalt vorgespannt | |
| column | Kolonne | |
| compressed air | Druckluft | |
| compressed asbestos fibreCAF | Asbest-Pressplatte (historisch) | Only in old plants; today replaced by asbestos-free fibre gaskets |
| concentric | konzentrisch | |
| condensate | Kondensat | |
| control | Regelung, Regler | |
| cooler | Kühler | |
| cooling rate | Abkühlgeschwindigkeit | Heat treatment: e.g. °C/h |
| copper tube | Kupferrohr | |
| corrosivity | Korrosivität | |
| countersunk | versenkt, Senkkopf- | |
| coupling | Muffe (Vollmuffe/Halbmuffe) | |
| crude oil | Rohöl | |
| delivery line | Förderleitung | |
| dial gauge | Messuhr | |
| discharge | Austritt, Druckseite (Pumpe), Ablass | discharge line on pumps = pressure line; discharge cock = drain cock |
| dotted line | gestrichelte Linie | |
| double extra strongXXS | doppelt extra stark (XXS) | Not generally equal to Sch 160 |
| drain | Entleerung, entleeren | |
| drawingDWG | Zeichnung | |
| eccentric | exzentrisch | |
| elbow | Rohrbogen (Formstück) | LR = 1.5 D, SR = 1 D |
| elevationEL | Höhenkote, Höhe; Ansicht | On drawings, ‘EL +12.500’ = elevation (height level) |
| exhaust steam | Abdampf | |
| extra heavy | extra schwer (XS) | |
| extra strongXS | extra stark (XS) | Corresponds to Sch 80 only up to NPS 8 |
| face to faceF/F | Baulänge (Armatur) | |
| faced and drilled | plangedreht und gebohrt | |
| female thread | Innengewinde | |
| field test | Baustellenprüfung | |
| field weldFW | Baustellennaht | |
| filler metal | Schweißzusatz(werkstoff) | filler plate = packing plate (German: Futterblech) |
| fire water | Löschwasser | fire water point = fire water connection |
| first coat / primer | Grundanstrich, Grundbeschichtung | |
| flange | Flansch | |
| flat faceFF | glatte Dichtfläche (ohne Dichtleiste) | EN 1092-1 form A |
| flexible hose | Schlauch, Metallschlauch | |
| flow meter | Durchflussmesser | |
| flow sheet / P&ID | Fließbild, R&I-Schema | |
| foolproof | narrensicher, fehlbedienungssicher | |
| foot valve | Fußventil | |
| forged steel | Schmiedestahl | |
| foundation | Fundament | |
| frostproof | frostsicher | |
| gasket | Dichtung | |
| gate valve | Absperrschieber | |
| gauge | Messgerät, Manometer; Lehre | |
| gauge glass | Schauglas, Standglas | |
| gland | Stopfbuchse | |
| globe valve | Absperrventil, Durchgangsventil | Not to be confused with a ball valve (German: Kugelhahn) |
| grade | Güte, Werkstoffsorte | e.g. ASTM A106 Grade B |
| ground level / grade | Geländeoberkante (GOK) | |
| heat exchanger | Wärmetauscher, Wärmeübertrager | |
| heat treatment | Wärmebehandlung | |
| heater | Erhitzer, Ofen | |
| heating coil | Heizschlange | |
| hexagon (hex) | Sechskant | |
| hose connection | Schlauchanschluss | |
| inlet | Eintritt, Einlass | |
| inside diameterID | Innendurchmesser | |
| installation | Montage; Anlage | |
| insulation, insulated | Isolierung/Dämmung, isoliert | |
| invert (elevation) | Rohrsohle (Höhe Innenunterkante) | On isometrics: elevation of the inside bottom of the pipe |
| iron pipe sizeIPS | Nennweite nach US-Rohrmaßsystem | |
| item no. | Pos.-Nr. | |
| jacking bolts / jack screws | Abdrückschrauben | On flanges, used to push the joint apart |
| joint | Verbindung; Flanschverbindung | |
| lap joint flange | Losflansch mit Bördel | |
| lap weld | Überlappnaht | |
| large end bevelled / plain / threaded | großes Ende angefast / glatt / mit Gewinde | |
| level | Ebene, Höhe; Füllstand | |
| line | Leitung | |
| line pipe | Leitungsrohr | |
| lining | Auskleidung | |
| long radiusLR | langer Radius (Bogen 1,5 D) | |
| low pressureLP | Niederdruck | |
| machined | maschinell bearbeitet | |
| main line / header | Hauptleitung, Sammler | |
| malleable iron | Temperguss | |
| manufacturing control | Fertigungsüberwachung | |
| master valve | Hauptabsperrventil | |
| match line | Anschlusslinie (Zeichnungsübergang) | |
| minutes of meetingMoM | Besprechungsprotokoll | |
| mitre / lobster back bend | Segmentbogen | |
| movable support | Loslager, bewegliche Unterstützung | |
| needle valve | Nadelventil | |
| nipple | Nippel | swaged nipple = reducing nipple |
| not to scaleNTS | nicht maßstäblich | |
| nozzle | Stutzen | |
| nut | Mutter | |
| one end bevelled / plain / threaded | einseitig angefast / glatt / mit Gewinde | |
| orifice flange | Messblendenflansch | |
| outlet | Austritt, Auslass | |
| outside diameterOD | Außendurchmesser | |
| outside screw and yokeOS&Y | außenliegendes Spindelgewinde mit Joch | Gate valve design |
| overhead | Gemeinkosten; über Kopf | In installation work usually ‘overhead’ as a welding position |
| pet cock | Probierhahn, Entlüftungshähnchen | |
| piece mark | Teilekennzeichnung, Positionsmarke | |
| pinhole | Pore, Nadelstichpore; kleine Bohrung | In welds/leaks = pore |
| pipe rack / pipe track | Rohrbrücke | |
| pipe support | Rohrhalterung, Rohrunterstützung | |
| pipe wrench | Rohrzange | |
| pipeline | Rohrleitung, Fernleitung | |
| pitch circle diameterPCD | Lochkreisdurchmesser | |
| plug valve | Kükenhahn | |
| post weld heat treatmentPWHT | Wärmebehandlung nach dem Schweißen | |
| pound per square inch (psi) | psi (1 psi ≈ 0,0689 bar) | |
| power plant | Kraftwerk | |
| preheat | Vorwärmen | |
| quality controlQC | Qualitätskontrolle | |
| raised faceRF | Dichtleiste | EN 1092-1 form B1/B2 |
| random length | Herstelllänge (unbestimmte Länge) | |
| raw material | Ausgangswerkstoff, Rohstoff | |
| reboiler | Umlaufverdampfer (Reboiler) | |
| reducer | Reduzierstück | concentric/eccentric reducer (German: konzentrisch/exzentrisch) |
| reinforcing pad | Verstärkungsblech (Sattelblech) | |
| relief valve | Überdruckventil, Sicherheitsventil | |
| remote control | Fernbedienung, Fernsteuerung | |
| return bend | 180°-Bogen (U-Bogen) | |
| ring type jointRTJ | Ringjoint-Dichtfläche (RTJ) | |
| rising stem | steigende Spindel | |
| rupture disc | Berstscheibe | |
| safety valve | Sicherheitsventil | |
| sample outlet | Probenahmestutzen | |
| sampling cock | Probenahmehahn | |
| scheduleSch | Schedule (Wanddickenreihe) | In a piping context always the wall thickness series to ASME B36.10 |
| screwed | geschraubt, mit Gewinde | |
| seal weld(ed) | Dichtnaht, dichtgeschweißt | |
| seamlessSMLS | nahtlos | |
| seat | Sitz | |
| section | Schnitt; Abschnitt | |
| shut-off valve | Absperrarmatur | |
| shutdown / plant going down | Anlagenabstellung, Stillstand | |
| side view / side elevation | Seitenansicht | |
| sight glass | Schauglas | |
| slip-on flangeSO | Überschiebflansch | |
| slope | Gefälle | |
| small end bevelled / plain / threaded | kleines Ende angefast / glatt / mit Gewinde | |
| smooth finish (flange face) | feingedrehte Dichtfläche | |
| socket weldSW | Muffenschweißverbindung | SW fittings to ASME B16.11 |
| spade / blind | Steckscheibe | Pressure testing, isolation during work |
| spectacle blind | Brillensteckscheibe | |
| stack | Kamin, Schornstein | |
| staff | Personal | |
| stainless steelSS | nichtrostender Stahl, Edelstahl | |
| stand-by | Reserve | |
| standard wire gaugeSWG | Drahtlehre (Draht-/Blechdicke) | |
| steam out | ausdampfen | Cleaning plant components with steam |
| steam traced | dampfbegleitbeheizt | |
| steam trap | Kondensatableiter | |
| straddle (bolt holes) | Schraubenlöcher beidseitig der Mittellinie | Bolt pattern: no hole on the centre line |
| strainer | Schmutzfänger, Sieb | |
| strength | Festigkeit | |
| stress | Spannung | |
| stress relief / stress relieving | Spannungsarmglühen | Post-weld heat treatment |
| stud bolt | Bolzen (Gewindebolzen) | On flanges, fitted with nuts on both ends |
| support | Halterung, Unterstützung | |
| swaged | eingezogen, reduziert | |
| swing pipe | Gelenkrohr | |
| tangent lineTL | Tangentenlinie (Übergang Mantel–Boden) | |
| tank farm | Tanklager | |
| tap, tapping | Anbohrung; Gewindebohrer | hot tap = tapping under operating pressure |
| taper | Konus, Verjüngung | |
| tensile strength | Zugfestigkeit | |
| test | Prüfung | pressure test = German Druckprobe; hydrotest = hydrostatic (water) pressure test |
| thermowell | Thermometerschutzrohr | |
| thickness | Dicke | |
| thread, threaded | Gewinde, mit Gewinde | |
| to be checked and adjusted in field (field fit) | auf der Baustelle prüfen und anpassen (Baustellenanpassung) | Drawing note |
| to fit, pipe fitter | vorrichten, Vorrichter/Rohrschlosser | |
| to flush | spülen | |
| to reject | zurückweisen; (Prüfung) nicht zulässig | |
| top of pipeTOP | Rohroberkante (OK Rohr) | |
| top of steelTOS | Oberkante Stahlbau | |
| top view / plan | Draufsicht | |
| trap | Abscheider; Kondensatableiter | |
| trench | Graben | |
| underground | erdverlegt | |
| union | Rohrverschraubung | |
| unit | Anlage, Anlagenteil; Einheit | |
| valve seat | Ventilsitz | |
| valve stem | Ventilspindel | |
| vapour pressure | Dampfdruck | |
| vent | Entlüftung | |
| wall thicknessWT | Wanddicke | |
| washer | Unterlegscheibe | |
| wedge | Keil | |
| weld | Schweißnaht, schweißen | |
| weld cap | Kappe (Formstück); Decklage (Naht) | Depending on context: fitting or final weld layer (capping pass) |
| welding elbow | Einschweißbogen | |
| welding neck flangeWN | Vorschweißflansch | |
| wire rope | Drahtseil | |
| working pointWP | Bezugspunkt, Schnittpunkt | Isometric: intersection point of pipe centre lines |
| workpiece | Werkstück | |
| wrench | Schraubenschlüssel | torque wrench = German Drehmomentschlüssel |
Compiled by HSOS from practical experience on international sites, without guarantee. Project-specific terms from the client’s piping class and specification take precedence.
Typical notes on English isometrics
All dimensions and elevations to be checked and adjusted in field.
All dimensions and elevations are to be checked and adjusted on site (field fit).
All screwed connections to be seal welded except plugs.
All threaded connections are to be seal welded, except plugs.
FW = field weld
Field weld – made only during installation on site, not during prefabrication.
NTS = not to scale
Not to scale – take dimensions only from the dimension figures, do not measure off the drawing.
Old DIN designations on as-built drawings? See the overview of piping standards old and new →
Frequently asked questions
What do BOP, TOP and EL mean on an isometric?
BOP (bottom of pipe) is the underside of the pipe, TOP (top of pipe) the top of the pipe, EL (elevation) the height relative to the plant datum. Pipe racks and supports are usually dimensioned to BOP because that is where the line rests. In German: Rohrunterkante, Rohroberkante, Höhenkote.
What is the difference between elbow and bend?
An elbow is a butt-welding fitting (German: Rohrbogen, to ASME B16.9 or EN 10253); a bend is formed from straight pipe (German: gebogener Rohrbogen). LR (long radius) means a bend radius of 1.5 × D, SR (short radius) 1 × D.
What is a “spectacle blind”?
A spectacle blind (German: Brillensteckscheibe) is an open ring spacer and a solid blind joined by a web. It stays permanently between the flanges and is swung round to isolate the line. A single blind plate is called a spade or blind (German: Steckscheibe).
International experience, documented in your language
HSOS works in refineries, chemical parks and power plants across Europe – to English specifications as well as DIN EN, with documentation in the language your project needs.