Kaxite Type F flange insulation kits are the standard raised-face isolation solution for RF flanged joints. The gasket covers only the raised face area inside the bolt circle — the minimum insulation geometry that still provides complete electrical isolation and full seal performance across the joint. Each kit is supplied as a complete pre-packed set: insulating gasket, insulating sleeves and insulating washers, matched to the flange bolt pattern and labelled with flange size and pressure rating. Materials include reinforced phenolic (standard), Minlon (high toughness) and Mylar (thin section). Kits are available for ASME B16.5, ASME B16.47, API 6A and DIN/EN flanges, Class 150 through Class 2500. Standard sizes ship in 7–15 days, custom sizes in 15–30 days.
Type F flange insulation kits are the standard raised-face insulation solution for RF flanged joints. Unlike the full-face Type E design, the Type F gasket covers only the raised face area inside the bolt circle — the minimum insulation geometry that still provides complete electrical isolation and seal performance across the joint.
This is the kit specified where the flange face is standard raised face (ASME B16.5, B16.47 and equivalents), the raised face is the primary sealing surface, and material efficiency matters at production volumes. Each kit is a complete isolation set — gasket, sleeves and washers — pre-packed and labelled with the flange size and pressure rating.
The Type F kit is one of four standard flange insulation configurations — D, E, F and specialty types — used across the pipeline industry. The choice between them is driven by the flange face geometry, not by preference: RTJ flanges require a Type D kit, full-face protection calls for a Type E kit, and the standard raised-face joint uses the Type F kit.
Type F applies where the flange is a standard raised-face design and the raised face inside the bolt circle is the only sealing surface. This is the majority of industrial raised-face joints, which makes the Type F kit the most frequently supplied kit in the range.
On most pipelines, the isolation strategy uses different kit types at different joints. Buried joints with a risk of bridging across the flange edge typically use Type E (full face + tape wrap). Surface raised-face joints where only the seal area needs isolation use Type F — the lower-cost option that still provides complete dielectric isolation through the bolting. The two kits are complementary, not interchangeable.
Each kit ships pre-packed as a complete isolation set — no missing parts, no second order on site. The three core components are matched to the flange bolt pattern and pressure class.
Each kit is labelled on the outside of the pack with the flange size and pressure rating so it can be matched to the joint on site without counting or measuring.
The default material across the full Type F range. High compressive strength, high dielectric strength, proven performance across standard industrial flanged joint temperature and pressure ranges.
Specified where higher toughness and impact resistance are needed — offshore, heavy industrial piping, and any joint subject to vibration and thermal cycling.
Thin-section isolation washer material for tight-profile kit configurations. High dielectric strength in very thin sections, allowing the isolation layer to be integrated without added bolt load.
The four flange insulation kit types are not interchangeable. Use the table below to match your flange to the correct kit type.
| Kit Type | Flange Face | Gasket Coverage | Typical Service |
|---|---|---|---|
| Type F | Raised face (RF) | Raised face only — inside the bolt circle | Standard RF flanged joints; material-efficient isolation at production volumes |
| Type E | Raised face / flat face | Full face — same OD as flange, precision bolt holes | Full-face protection; outdoor and buried lines where shorting risk is high |
| Type D | RTJ (ring joint) | Inside the ring groove | High-pressure oil & gas, API 6A wellheads, refinery RTJ piping |
| Type B / C | Raised face | Application-specific variants | Legacy flange specifications and special bolt patterns |
Not sure which type fits your flange? Send the flange drawing, standard (ASME B16.5, B16.47, API 6A, DIN/EN) and pressure class and we will confirm the correct kit and material.
Send the five details below and Kaxite will confirm the correct kit type, material and lead time. Standard sizes ship from stock or on short lead time — typically 7–15 days. Custom sizes are produced to order in 15–30 days.
The Type F gasket covers only the raised face area inside the bolt circle — the minimum geometry that provides full electrical isolation and seal performance on a standard raised-face joint. The Type E gasket has the same outside diameter as the flange itself, giving full-face protection and self-centring on the flange inside diameter. Type F is the cost-efficient choice for standard RF joints; Type E is specified where the full flange face must be protected or where the joint is exposed to outdoor conditions where foreign material could bridge the isolation gap.
No. RTJ (ring joint) flanges require a Type D kit, where the gasket is profiled to sit inside the ring groove. The Type F gasket geometry does not match the RTJ ring groove and will not provide a proper seal or the required insulation geometry on that flange type.
Yes. Type F kits are produced for ASME B16.5, ASME B16.47, API 6A and DIN/EN flange standards across Class 150 through Class 2500 and equivalent API pressure classes. Send the standard, size and pressure class and we will confirm availability.
For offshore and heavy industrial service where vibration and impact loads are present, Minlon is the recommended material — higher toughness and impact resistance than phenolic while retaining the required dielectric properties. For standard onshore industrial piping, reinforced phenolic is the default.
Every kit is supplied pre-packed as a complete set — one gasket, the correct number of sleeves and washers for the flange bolt pattern, and any additional isolation components required. The pack is labelled on the outside with the flange size and rating.
Yes. Custom bolt patterns, non-standard raised face diameters and legacy flange specifications are produced to order. Send the dimensioned flange drawing and we will quote accordingly.
Yes. In addition to complete kits, Kaxite supplies insulation washers and insulation sleeves as individual components for maintenance and replacement. See the phenolic sleeve and phenolic insulating washer product pages.
Standard sizes ship from stock or on short lead time — typically 7–15 days depending on quantity. Custom or non-standard sizes are produced to order in 15–30 days. Send the specification for a confirmed delivery schedule.
Send the flange standard, size, pressure class and quantity. Kaxite will confirm the correct kit type, material and lead time. If the flange is RTJ we will recommend the Type D kit; if the application requires full-face protection we will recommend the Type E kit.
