RF- und RTJ-Flansche für Hochdruckanwendungen
Direkte Antwort
RF flanges seal by compressing a gasket against two raised faces. RTJ flanges seal by deforming a metallic ring gasket inside matched grooves. RTJ is commonly selected for severe high-pressure or high-temperature services when the line class and mating equipment require it, but it is not automatically better for every application. Facing, Dichtung, class and mating geometry must match exactly.
Wichtige Erkenntnisse
- RF and RTJ describe different sealing systems, not cosmetic face options.
- An RTJ joint requires two compatible grooves and the specified metal ring.
- High pressure alone does not decide the facing; the line class and service do.
How RF and RTJ sealing differ
| Besonderheit | Erhöhtes Gesicht (RF) | Ring-Type Joint (RTJ) |
|---|---|---|
| Sealing element | Compressed gasket on raised surfaces | Metal ring gasket seated in matched grooves |
| Contact pattern | Broader gasket contact area | Concentrated metal-to-metal ring contact |
| Common use | Wide range of process and utility duties | Severe pressure/temperature duties defined by line class |
| Critical inspection area | Face flatness, finish and damage | Groove profile, beenden, corrosion and mechanical damage |
Both designs can provide reliable service when correctly specified, bearbeitet, assembled and maintained. Neither facing compensates for inadequate bolting, misalignment or uncontrolled external loads.
When RTJ is commonly specified
RTJ connections are often found in higher-pressure refinery, Petrochemie, offshore and oil-and-gas systems. The metal ring and groove arrangement can suit demanding joint requirements, but selection must follow the project line class and the available facing provisions for the selected standard and class.
Installation quality is critical. The ring material and profile must be correct, grooves must be clean and undamaged, and the flanges must be aligned. A reused or incorrect ring can compromise the seal even when the flange material and class are correct.
Compatibility and conversion traps
An RF flange should not be bolted to an RTJ flange as a normal field solution. The facing geometry and sealing concept differ. Converting a joint requires engineering approval, compatible replacement components and verification of dimensions, rating, Dichtung, bolting and connected equipment.
Buyers should state the exact facing and any groove designation required by the project. “RTJ flange” by itself may still omit the standard, NPS, Klasse, Material, Flanschtyp, groove or ring reference, bore and finish.
Inspection and ordering checklist
- ASME standard, NPS, class and flange type
- RF or RTJ facing and required finish
- RTJ groove and ring-gasket designation where applicable
- ASTM material specification and exact grade
- Mating-flange or equipment-nozzle details
- Face or groove dimensional inspection
- Protection against corrosion and handling damage
- Bolting, Dichtung, MTC, PMI- und NDE-Anforderungen
Keep machined faces protected through shipping and storage. Damage in an RTJ groove or across an RF sealing path can be more consequential than rust on a non-sealing exterior surface.
Häufig gestellte Fragen
Is RTJ always better than RF at high pressure?
NEIN. RTJ is common in severe service, but the approved standard, Klasse, line class, gasket strategy and mating equipment determine the correct facing.
Can an RF flange mate with an RTJ flange?
They are not a normal compatible pair. Any conversion requires engineered replacement or an approved joint solution.
Can an RTJ ring gasket be reused?
Metal rings are generally treated as single-use sealing elements unless the governing procedure explicitly permits otherwise.
Primäre Standards, auf die verwiesen wird
- ASME B16.5-2025 – Rohrflansche und Flanschverbindungen, NPS 1/2 Durch NPS 24
- ASME B16.47-2025 – Stahlflansche mit großem Durchmesser, NPS 26 Durch NPS 60
Die Standards wurden anhand der Herausgeberseiten überprüft 3 August 2026. Kaufen und wenden Sie immer die vom Projekt angegebene Edition an.
Fordern Sie ein Angebot für einen Flansch aus legiertem Stahl an
Senden Sie die Materialqualität, Standard, NPS, Druckklasse, Flanschtyp, gegenüber, Rohrplan, Mengen- und Prüfanforderungen. Unser Team wird die technische Beschreibung vor dem Angebot prüfen.
