A gasket is the cheapest part in a node and at the same time the one that most often stops equipment: the seal is compressed through, oil or pressure leaks, and the line stands until the penny component is replaced. Rubber gaskets swell in oil, harden in frost, and are compressed through by abrasive in a few shifts. Polyurethane gaskets from TIMOL factory hold higher pressure, are unaffected by petroleum products, and have wear resistance approximately 2-5 times higher than rubber. This article covers where these gaskets work, why they outperform rubber, PTFE, and silicone, and how to order a seal to your drawing.
What Polyurethane Gaskets Seal
A polyurethane gasket seals the interface between parts and compensates for surface irregularities, preventing the passage of liquid, gas, or dust. Under bolt load it elastically deforms, fills micro-irregularities on the flanges, and creates tight contact around the full joint perimeter.
These gaskets are installed in pipeline flange joints, pump and gearbox covers, hydraulic and pneumatic nodes, and split mechanism housings. A separate large class is gaskets and seals in shock absorbers and moving nodes, where the gasket not only sits in position but works under pressure and cyclic loading.
Polyurethane is especially appropriate where the gasket is subjected not only to bolt load but also to friction, vibration, or contact with abrasive particles. The smooth dense surface resists compression by hard inclusions, and elasticity returns the gasket to shape after load removal. The range of sealing products is in the catalogue.
Why Polyurethane Is Replacing Rubber, PTFE, and Silicone
Polyurethane combines strength, wear resistance, and oil resistance, which is how it beats traditional gasket materials. DIN 53516 abrasion of polyurethane is 38-39 mm³; for SBR rubber 100-200 mm³; for silicone rubber 150-350 mm³; for PTFE 200-500 mm³. Under friction and abrasive conditions, a polyurethane gasket wears several times more slowly than any of these materials.
Against rubber, polyurethane wins on strength and pressure. Tensile strength of polyurethane is 39-87 MPa versus 8-20 MPa for SBR and 10-25 MPa for NBR. Tear resistance of polyurethane is 40-120 kN/m, while in most rubbers it is several times lower. Under high pressure, a polyurethane gasket therefore does not split at the edge and does not extrude into the gap as easily as a rubber one.
PTFE and silicone have their own strengths, which should be acknowledged honestly. PTFE is chemically inert and withstands from -200 to +260 °C; silicone works from -60 to +230 °C. But both have very low wear resistance and a tendency to creep under load: PTFE cold-flows under sustained pressure; silicone has tensile strength of only 5-12 MPa. Where the primary requirements are chemical inertness or extreme temperature, they are the right choice. Where the gasket carries mechanical load, friction, and pressure, polyurethane is more reliable in service.
| Material | Abrasion DIN 53516, mm³ | Operating t, °C | Tensile strength, MPa | Tear resistance, kN/m | Oil resistance |
|---|---|---|---|---|---|
| Polyurethane TIMOL | 38-39 | -60…+100 | 39-87 | 40-120 | excellent |
| NBR rubber | 80-150 | -30…+100 | 10-25 | 10-50 | good |
| SBR rubber | 100-200 | -40…+80 | 8-20 | 8-35 | poor |
| Silicone rubber | 150-350 | -60…+230 | 5-12 | 5-30 | moderate |
| PTFE | 200-500 | -200…+260 | 15-35 | n/a | excellent |
The table shows the distribution of roles: silicone and PTFE win on temperature range but are several times inferior to polyurethane on wear, tensile strength, and tear resistance — so in mechanically loaded seals polyurethane remains the working choice.
Engineer’s tip: for high pressure, choose harder polyurethane and specify minimum installation clearance in the joint. The main enemy of a gasket under pressure is extrusion — when material is pushed into the gap between parts and gradually fails. Harder gasket material and tight seat geometry eliminate this effect. For uneven or rough-machined flanges, conversely, use softer material that fills the irregularities and gives sealing without overtorquing.
Service Conditions and Application Limits
For a gasket to deliver its full calculated service life, it is important not to exceed the material’s operating conditions. Sustained operation above +100 °C accelerates polyurethane fatigue, so for hot nodes the formulation is agreed separately or a different material selected. Sustained contact with aromatic solvents, ketones, and concentrated acids is also undesirable and requires compatibility checking.
Within the rated range, a polyurethane gasket behaves predictably: it holds oil, water, dilute acids and alkalis, petroleum products, salt solutions, and is resistant to ozone and UV in outdoor operation. This compares favourably with SBR rubber and natural rubber, which degrade quickly in sunlight and oil.
Correct installation is as important as the material. Mating surfaces are cleaned of old sealant, rust, and burrs; bolt torque is applied uniformly around the perimeter; and the clamping force is controlled so that the gasket seals but is not fully extruded. Casting technology and surface preparation are described in the reference information section.
Application Industries
Polyurethane gaskets are in demand in industries where seals work under pressure, vibration, or in contact with oil and abrasive. The factory’s total product range covers 12 industrial sectors, and gaskets are needed in almost every one.
Hydraulics and pneumatics use polyurethane seals for their ability to hold pressure without extrusion. Pump and compressor equipment values oil and wear resistance at disconnect interfaces. Agricultural and food machinery chooses polyurethane for moisture and detergent resistance and the fact that the gasket does not corrode. Mining and metallurgy use polyurethane gaskets where abrasive particles are present in the medium, which compress rubber through.
In all these cases polyurethane solves a common problem: extending the replacement interval of an inexpensive but critical part and eliminating the leaks that stop lines. Often the economic effect comes not from the gasket cost itself but from reducing unplanned shutdowns: a single hydraulic leak under load can cost more than a year’s supply of seals. More on material selection for specific applications is in the services section.
How to Order Polyurethane Gaskets to Size
To place an order, supply a drawing or sample gasket with dimensions and describe the operating conditions: pressure, working medium, temperature, and load character. Based on this data the technologist selects the hardness, polymer formulation, and seal geometry.
TIMOL factory manufactures gaskets of any shape by the free-casting process: ring, flange, profiled, with bolt holes and embedded elements. Both individual gaskets for repairing a specific node and production batches for equipment can be produced.
For consultation, calculation to your pressure, and ordering, contact TIMOL factory. Engineers will help select the material and manufacture the seal to your joint geometry.