Kammprofile Gasket with Loose Outer Ring

Kaxite KXT-1120 is built on a concentrically serrated solid metal core with a turned groove on the outer circumference that receives a separate locating ring. The ring is not machined into the core — it fits loosely in the groove, so it can move radially as the flange or core expands and contracts under thermal cycling. A soft sealing layer — graphite or PTFE — is bonded to both facing surfaces. The serrated geometry concentrates seating stress on the sealing faces, while the floating ring performs the centering function without introducing additional stress into the solid core.

The data below covers the standard KXT-1120 configuration. Non-standard core alloys, facings, thicknesses and diameters are quoted to drawing; include the flange standard and class in the enquiry for accurate pricing and lead time.

• ModelKXT-1120
• Gasket TypeKammprofile (camprofile) with loose / floating outer centering ring
• Core Material (standard)SS 316L / SS 304
• Core Material (options)Monel 400, Nickel 200, Inconel 600, Inconel 625, Incoloy 825, Hastelloy B-2, Hastelloy C-276, Titanium
• Facing MaterialFlexible graphite (standard) / PTFE (option)
• Core Thickness2 mm / 3 mm / 4 mm
• Standard Gasket Thickness3.5 mm / 4.0 mm / 4.5 mm / 5.0 mm
• Standard Size RangeDN 15–600 per ASME B16.5 Class 150–2500; custom to 2000 mm on drawing
• Flange StandardASME B16.5 / ASME B16.20 / EN12560-6
• Flange FacingRaised face (RF) and flat face (FF)
• Recommended Surface Finish3.2–6.3 μm Ra
• Ring ReplacementLoose ring can be replaced independently of the core
• Core ReusabilityYes — after cleaning, inspection and re-facing

The choice between an integral outer ring and a loose outer ring is a thermal-mechanical decision, not a stylistic preference. On the integral design, the centering ring is machined as part of the core — alignment is fixed, installation is single-piece, and there is no separate part to stock. That is the correct choice for the majority of ASME B16.5 standard flanges. The loose ring becomes the better specification when radial thermal movement or large flange diameter makes a rigid integral ring a liability: the independent ring can float in its groove as the flange and core expand at different rates, and it can be dismounted where access requires it. It also allows ring material to differ from core material, which matters when the centering function does not need the same alloy as the sealing core.

Two independent selections define the KXT-1120 envelope: the core alloy sets the temperature ceiling and mechanical strength, the facing material sets chemical compatibility and seating behaviour. The standard pairing — SS 316L core with flexible graphite facing — covers the broadest range of steam, hydrocarbon and high-temperature service. PTFE facing is specified where graphite is not chemically acceptable, at a lower temperature ceiling.

Cross-section: serrated core, turned groove and loose floating centering ring, with facing on both sealing surfaces.

The loose-ring Kammprofile gasket is specified where flange diameter, thermal movement or maintenance access makes the floating ring an operational advantage. The dominant application is large-diameter flanges on heat exchangers and pressure vessels — shell and channel connections where the flange OD exceeds the range at which an integral ring behaves rigidly, and where differential thermal expansion between the flange and the gasket core would otherwise load the ring. On high-pressure piping with frequent thermal cycling, the independent ring accommodates the radial movement of each cycle without inducing stress in the core or the sealing faces.

Additional service areas include vessel manways and handholes where the ring can be dismounted for access, valve bonnet and cap joints on large valves, pump and compressor casing splits on equipment that sees temperature cycling during start-up and shutdown, and pipeline flanges where the ring material may differ from the core material for cost or corrosion reasons. In refinery and petrochemical units, graphite-faced KXT-1120 gaskets are common on hydrocarbon, hydrogen and steam services; PTFE-faced variants appear on chemical and pharmaceutical duty where graphite contamination is unacceptable. For lower-pressure utility and water-line flanges, the spiral wound gasket range is typically more cost-appropriate; KXT-1120 is positioned for the high-integrity end of the flange sealing spectrum where thermal movement is a design consideration.

The serrated core concentrates stress at the groove crests, so a reliable seal develops at bolt loads significantly lower than those demanded by solid metal gaskets, while the same design tolerates high bolt loads without crushing. This matters on large-diameter flanges where bolt load is limited and on lighter-weight flanges where flange rotation is a concern. The floating ring does not carry sealing load — it performs only the centering function, and its position in the turned groove is maintained by the flange bolt circle rather than by bolt load.

A practical advantage of the loose-ring design is independent replacement: the ring can be replaced without replacing the core if it becomes damaged or if a different ring material is required. The metal core itself is reusable after service — disassembled, cleaned and inspected (including profile tracing where specified), with new facing material bonded before reinstallation. On expensive alloy cores — Monel, Inconel, Hastelloy or titanium — this can materially reduce lifecycle cost compared with single-use constructions. Reusability does not apply where the core shows mechanical damage, corrosion pitting or groove wear; the decision to reuse rests with the inspecting engineer against the applicable procedure.

Flange surface finish matters. Kammprofile gaskets with sealing layers are typically recommended for a surface finish of 3.2–6.3 μm Ra, with flange faces flat and free from deep radial scratches or dents. The turned groove on the core should be free from burrs or deformation that could prevent the loose ring from seating evenly. For guidance on gasket selection across different flange types and service conditions, the broader industrial gasket range provides a comparative starting point.

KXT-1120 is manufactured at Kaxite’s Ningbo facility and supplied factory-direct for OEM, MRO and project procurement. Core alloy, ring alloy and facing material are selected against the duty conditions, and the ring is sized to the flange standard and class. Where the ring material differs from the core material — for example, an SS 304 ring on an Inconel 625 core — the two are matched to the thermal expansion and corrosion requirements of the application. For buyers consolidating a gasket package, KXT-1120 can be combined with compression sheet and braided packing lines in a single shipment.

If the application falls outside the Kammprofile envelope entirely — for example, very low bolt load with a highly irregular flange surface — a non-asbestos sheet gasket may be the more practical specification.