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Klingersil C4400 Compressed Fiber
QS Gasket: Klingersil C4400 Compressed Fiber
Name: Klingersil C4400 Compressed Fiber
Standard: ASME B16.5
Material: Klingersil C4400
Max Temperature: 400℃
Size: 8 Inch
Pressure: 150LB
Complete Set: with G10 Sleeve and Washers and ZPS
Compound: with Aramid Fiber Reinforced with a Nitrile Binder
Standard: ASME B16.5
Material: Klingersil C4400
Max Temperature: 400℃
Size: 8 Inch
Pressure: 150LB
Complete Set: with G10 Sleeve and Washers and ZPS
Compound: with Aramid Fiber Reinforced with a Nitrile Binder
Quantity
Klingersil C4400 Compressed Fiber gasket, 8"×150LB, ASME B16.5 full set (includes G10 insulating sleeve, washer and ZPS).
Aramid fibre + NBR calendered at high temperature, withstands 400°C without burn-off, needs only 30 MPa specific sealing pressure, compensates flange defects instantly; oil-resistant, fuel-resistant, anti-cold-flow, dielectric strength >50 kV/mm, no corrosion after 1,000 h salt spray. First choice for electro-static isolation of flanges in power plants, chemical plants, LNG and marine service; install once, zero maintenance.
Aramid fibre + NBR calendered at high temperature, withstands 400°C without burn-off, needs only 30 MPa specific sealing pressure, compensates flange defects instantly; oil-resistant, fuel-resistant, anti-cold-flow, dielectric strength >50 kV/mm, no corrosion after 1,000 h salt spray. First choice for electro-static isolation of flanges in power plants, chemical plants, LNG and marine service; install once, zero maintenance.
When choosing gasket dimensions (ID, OD, thickness) the following points must be considered:
For non-metallic insulating gaskets dimensioning is not “measure the pipe bore and place the order”; it is a chain of calculations that superimpose service conditions, standards, tolerances and assembly behaviour.
For non-metallic insulating gaskets dimensioning is not “measure the pipe bore and place the order”; it is a chain of calculations that superimpose service conditions, standards, tolerances and assembly behaviour.
The core idea is simple: after compression the “effective sealing band” of the gasket must lie exactly in the peaks and valleys of the flange face roughness, without being crushed, blown out, or losing resilience because it is too thin.
The three dimensions are explained below, using Klingersil C4400 Compressed Fiber as the example to show how it performs in critical duties.
I. Inside diameter ID – “only bigger is allowed, never smaller”
1. Fluid erosion: ID must be ≥ flange bore + 2 mm to stop high-velocity fluid forming eddies at the step that cut the gasket lip.
Example: on a DN100 (φ114.3 mm) steam line an ID of 110 mm produces a “lacy edge” on the bore after 30 min, and leakage jumps to failure level.
1. Fluid erosion: ID must be ≥ flange bore + 2 mm to stop high-velocity fluid forming eddies at the step that cut the gasket lip.
Example: on a DN100 (φ114.3 mm) steam line an ID of 110 mm produces a “lacy edge” on the bore after 30 min, and leakage jumps to failure level.
2. Thermal growth + misalignment: for temperatures >200°C or FRP/lined pipe use flange bore + 3-5 mm to give room for expansion and offset.
3. Insulation requirement: if a flange isolation kit is used the ID must also clear the 1.5 mm wall thickness of the insulating sleeve to avoid point loading where sleeve and gasket meet.
> ✅ Klingersil C4400 Compressed Fiber has excellent erosion resistance; its high-density structure withstands edge cutting by high-speed steam or hydrocarbons.
II. Outside diameter OD – “cover the face but do not show”
1. Bolt-circle rule: OD ≤ bolt-circle dia – bolt-hole dia – 3 mm; otherwise the bolt head shears the outer edge while tightening and the ring “peels off”.
1. Bolt-circle rule: OD ≤ bolt-circle dia – bolt-hole dia – 3 mm; otherwise the bolt head shears the outer edge while tightening and the ring “peels off”.
2. Flange-face width: ASME B16.5 “raised-face OD” + 2-4 mm is enough to cover the sealing band; larger wastes material and increases blow-out moment.
3. Negative tolerance: non-metallic gaskets are usually supplied 0/-1 mm on OD to avoid interference with the neck chamfer of weld-neck flanges.
Example: 150LB 6"RF flange, raised-face OD 171 mm; choose OD 175 mm. If 185 mm is used blindly, the outer edge blows out at 0.8 MPa during hydro-test.
Example: 150LB 6"RF flange, raised-face OD 171 mm; choose OD 175 mm. If 185 mm is used blindly, the outer edge blows out at 0.8 MPa during hydro-test.
> ✅ When using Klingersil C4400 Compressed Fiber keep OD within raised-face OD +3 mm to balance sealing and blow-out resistance.
III. Thickness t – “too thin = no recovery, too thick = never tight”
1. Compression curve: aramid-fibre sheet (e.g. Klingersil C4400 Compressed Fiber) works best at 0.8-1.5 mm; below 0.5 mm recovery is <0.02 mm, too small to compensate for thermal relaxation; above 2.5 mm inter-layer slip creates “S”-shaped leak paths.
1. Compression curve: aramid-fibre sheet (e.g. Klingersil C4400 Compressed Fiber) works best at 0.8-1.5 mm; below 0.5 mm recovery is <0.02 mm, too small to compensate for thermal relaxation; above 2.5 mm inter-layer slip creates “S”-shaped leak paths.
2. Flange stiffness: a 150LB flange deflects ≈0.1 mm under 190 MPa bolt stress; gasket thickness must be ≥0.8 mm to bridge this deflection plus surface roughness (Ra 3.2 µm).
3. Dielectric strength: if the gasket must insulate to 2 kV DC a 1 mm mica-composite layer is needed; every 0.2 mm removed drops breakdown voltage by 400 V.
Example: on an LNG carrier at –104°C a 0.8 mm Klingersil C4400 Compressed Fiber leaked after cold shrink; changing to 1.2 mm gave 0.05 mm extra recovery and passed 500 thermal cycles.
IV. Four-step quick selection (recommended material: Klingersil C4400 Compressed Fiber)
① Look up flange standard → obtain raised-face OD d1, bolt-circle d2, hole dia d3.
② Calculate min ID = max (pipe bore + 2 mm, sleeve OD + 1 mm).
③ Calculate max OD = min (d1 + 4 mm, d2 – d3 – 3 mm).
④ Choose thickness from compression/recovery curve:
-<150°C, Class150 → Klingersil C4400 Compressed Fiber 0.8 mm
- 150-300°C, Class300 → Klingersil C4400 Compressed Fiber 1.2 mm
- >300°C, Class600 → Klingersil C4400 Compressed Fiber 1.5 mm + inner ring to prevent blow-out.
① Look up flange standard → obtain raised-face OD d1, bolt-circle d2, hole dia d3.
② Calculate min ID = max (pipe bore + 2 mm, sleeve OD + 1 mm).
③ Calculate max OD = min (d1 + 4 mm, d2 – d3 – 3 mm).
④ Choose thickness from compression/recovery curve:
-<150°C, Class150 → Klingersil C4400 Compressed Fiber 0.8 mm
- 150-300°C, Class300 → Klingersil C4400 Compressed Fiber 1.2 mm
- >300°C, Class600 → Klingersil C4400 Compressed Fiber 1.5 mm + inner ring to prevent blow-out.
> Conclusion: Klingersil C4400 Compressed Fiber is a high-performance compressed-fibre gasket material that combines sealing, resilience and electrical insulation; accurate control of ID, OD and thickness gives a large increase in long-term flange reliability.
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