Non-rounded Spiral Wound Gaskets

At Kriloha Ltd., we recognize that not every pressure boundary is a perfect circle. In many industrial heritage systems and specialized modern vessels, access points like manways and handholes are designed in oval or rectangular shapes to facilitate easier entry or to fit specific mechanical constraints. Sealing these “non-rounded” openings requires a level of manufacturing sophistication that goes far beyond standard circular winding. The Kriloha Non-rounded Spiral Wound Gasket is engineered specifically to provide a high-integrity seal for these challenging geometries.

The primary engineering hurdle with non-rounded gaskets is maintaining consistent density. In a circular gasket, the winding tension is constant; however, in an oval or rectangular gasket, the “pull” on the metallic strip changes as the winding head moves around a sharp radius versus a flat side. Kriloha addresses this with our proprietary Variable Tension Winding (VTW) system. This technology automatically adjusts the winding force in real-time, ensuring that the gasket doesn’t have “soft spots” at the corners or “hard spots” on the flats. This uniformity is what makes a Kriloha gasket fundamentally more reliable than generic alternatives, which often suffer from uneven compression and premature failure.

Furthermore, non-rounded gaskets are often subject to “internal buckling” because the pressure forces act differently on an elongated shape. To combat this, Kriloha reinforces the inner plies of our non-rounded gaskets with additional metallic layers, providing a structural skeleton that resists the inward pull of vacuum or the outward push of high-pressure steam. Whether you are sealing a vintage steam boiler or a cutting-edge chemical autoclave, our gaskets utilize high-purity flexible graphite to conform to the often-pitted surfaces of older flange faces.

As a premier supplier of rubber seals and gaskets, Kriloha Ltd. maintains an extensive library of templates for all major OEM boiler and vessel brands. This allows us to provide rapid-response manufacturing for non-standard shapes, minimizing downtime during emergency repairs or scheduled turnarounds. When you specify a Kriloha Non-rounded SWG, you are choosing a product that combines old-world craftsmanship with 21st-century CNC precision, ensuring that your inspection ports and manways remain leak-free under the most demanding conditions.

Primary Use Cases

Boiler Manway Covers: The industry standard for sealing oval-shaped access doors in steam boilers and tanks.
Handholes and Inspection Ports: Reliable sealing for small, non-circular openings in pressure vessels.
Autoclaves and Sterilizers: Ensuring a vacuum-tight and pressure-tight seal in medical and industrial processing equipment.
Engine Exhaust Manifolds: Custom-shaped gaskets for non-standard rectangular or oblong exhaust ports.
Gas Turbine Access Doors: High-temperature sealing for irregular-shaped turbine housing apertures.

FAQs

Why is it harder to manufacture an oval gasket than a round one?

In an oval shape, the winding speed and tension must change constantly as the machine goes around the “corners” compared to the “flats.” Without precise CNC control, the gasket will have inconsistent density, leading to leaks.

What measurements does Kriloha need for a custom non-rounded gasket?

We typically need the Long ID, Short ID, the width of the sealing face (flange width), and the required thickness. A physical template or a CAD drawing is always preferred for complex shapes.

Are these gaskets “Fire-Safe”?

Yes. Because they are constructed from metallic strips and inorganic fillers like graphite, they are inherently fire-safe and can withstand extreme temperatures that would destroy a standard rubber seal.

Can I use a standard round gasket and “squeeze” it into an oval shape?

Absolutely not. Forcing a round spiral wound gasket into an oval shape will cause the windings to separate and the filler to fall out, leading to immediate failure upon pressurization.

Do non-rounded gaskets require an inner or outer ring?

Most manway gaskets are “sealing elements only” because they fit into a machined groove or are held by a cover plate. However, Kriloha can manufacture them with custom rings if your specific hardware requires a compression stop.