Spiral Wound Gaskets

SPIRAL WOUND

GASKETS

Spiral wound gaskets consist of a metal strip with a “V” profile wound in a spiral form and filled with soft material.

The soft material provides the spiral wound gasket with sealing properties and the metal strip provides the stiffness properties.

The combination of these two types of materials makes spiral wound gaskets ideal for sealing fluids at high temperatures (up to 1000°C) and under high pressure conditions (up to 250°C).

“Mechanical durability, high flexibility and exceptional recovery in heavy operation conditions”

With inner ring, outer centering ring or both.
TA LUFT Fugitive Emissions Prevention Certificate (environmentally friendly)
Standard sizes acc/to ASME, EN or to customers specifications.
SS304L, SS316L, SS321.
Successfully used in a wide range of applications: piping, heat exchangers or pressure vessels on steam, petrochemical, nuclear and marine plants.
Extraordinary ability to adapt with recovery and flexibility under frequent fluctuations of pressure and temperatures.

Materials

In general, the metal strip of the spirals is manufactured in the classic 18/8 type stainless steels (AISI-316L, AISI-304, AISI-321), special stainless steels (AISI-309 or similar) and other materials such as Monel-400, Titanium, etcetera.

The soft filling (material that specifically performs the sealing function) can be supplied in Graphite, PTFE, ceramic material or other asbestos-free materials.

Profiles

materiales colores juntas espirometalicas

The most common nominal thicknesses for spirals are 3.2 mm and 4.5 mm.
For diameters up to 1200 mm, 4.5 mm thickness is recommended; for diameters up to 1800 mm, 5.5 mm thickness and for sizes up to 4000 mm, 6.5 mm or 7 mm thickness is recommended.
for sizes up to 4000 mm it is advisable to use 6.5 mm or 7 mm thickness.

Profiles and values

Profile	Section	Material/ Coating	K_O	K₁	R_Z *
Profile	Section	Material/ Coating	[N/mm]	[mm]	(µm)
SpV1		Steel Cr-Steel CrNi-Steel Monel Titanium	50 b_D	1,3 bD	12,5 a 25
SpV2			55 b_D	1,4 bD
SpV2J			55 b_D	1,4 bD
SpZ1J		CrNi steel Asbestos free PTFE o Graphite	40 bD	1,2 bD	25 a 50
SpZ2J		CrNi steel Asbestos free PTFE o Graphite	40 bD	1,2 bD	25 a 50

*Recommended surface finish for the surface of the flange

We also manufacture spiral wound gaskets for fittings and equipment. It is also possible to manufacture oval shapes (for manholes) and there is also the possibility to manufacture special spiral wound gaskets with metal-plastic ribs for heat exchangers.

Spiral wound seals with an inner retaining ring are also available (profiles SpV1J, SpV2J). The inner ring makes the seal safer by protecting the spiral from the possible turbulent action of the fluid and from pressure and/or temperature oscillations, additionally preventing the lateral sliding effect that could occur.

In SpZ (zone) profile spiral wound seals, the filling is usually made of graphite and the middle zone of PTFE or special compressible graphite. In this type of seals, lower closing deformation forces are required, as the surface pressure is mainly concentrated in the middle zone.

The minimum surface pressure is 30 N/mm2, instead of the 45-50 N/mm2 that would be required for a normal gasket. The combined filler (the zone) also protects the gasket better against high pressures or varying load conditions, and its configuration allows it to withstand higher stresses than a normal gasket.

With spiral wound seals, values of 10-8 mbar/ s-1 m-1 (measured with a Helium leak detector) can be achieved, considering a central PTFE zone of DN-150.

Spiral wound gaskets profile SpFS in “fire-safe” version are equipped with PTFE-filled tapes on the inside and graphite-filled tapes on the outside. They are suitable for applications where the product must not come into contact with graphite and where the operating temperature is below 280°C.

For temperatures above 280°C with the requirement of “fire-safe“, SpV spiral wound gaskets with graphite tape on the outside or SpZ gaskets with graphite zone can be used.

Surface pressure

Profile	Material	Surface pressure (N/mm2)
		T = 20ºC		T = 300ºC
		smin	smáx	smin	smáx
SpV1 SpV2	1.4541/Graphite	50	150	60	120
SpV1J, SpV2J SpZ1, SpZ2	1.4541/Graphite 1.4541/Graphite: PTFE	50 30	300 150	60 45	220 120
SpZ1J, SpZ2J	1.4541/Graphite: PTFE	30	300	45	220
SpV1 , SpV1J SpZ1 , SpZ1J	1.4541/Graphite 1.4541/Graphite+ PTFE	70 70	View note View note	70 70	View note View note

Note: Spiral wound metals marked with (*) are assumed to be confined in a tongue and groove pocket; the seal is based on metal-to-metal contact, which is why the upper limit of the smáx is not limited by the gasket material but by the strength of the flange.

Everything You Need to Know About Spiral Wound Gaskets

Spiral wound gaskets are essential components in industrial applications, particularly where tight sealing and resistance to high temperatures and pressures are critical. In this article, we’ll explore what they are, how they work, their advantages, and their most common applications.

What Are Spiral Wound Gaskets?

Spiral wound gaskets are mechanical seals made from a combination of metallic and non-metallic materials. These gaskets are designed to withstand extreme conditions, offering exceptional performance in high-pressure and high-temperature systems.

The typical structure of a spiral wound gasket includes:

Spiral metal core: Usually made of stainless steel, Monel, or other corrosion-resistant metals.
Non-metallic filler: This material can be graphite, PTFE, KEMICULITE® (mica), or other compounds, depending on the application. Its purpose is to ensure a tight seal.
Outer ring (optional): Helps maintain alignment and increases the gasket’s rigidity. It can be manufactured from Monel, carbon steel, or other metals.
Inner ring (optional): Assists in maintaining alignment and adds rigidity. It can be made of any metallic material or a soft material, such as GORE®, to act as a barrier protecting the flange and the gasket from corrosive fluids.

How Do Spiral Wound Gaskets Work?

The spiral design allows the gasket to compress uniformly, distributing pressure across its surface. The non-metallic filler acts as a flexible sealing material, while the metallic core provides strength and mechanical stability.

When subjected to pressure, the gasket deforms slightly to fill surface irregularities, ensuring a leak-proof seal.

Advantages of Spiral Wound Gaskets

High resistance to extreme temperatures: Depending on the materials used, they can withstand temperatures ranging from -200°C to over 1000°C.
Stability under high pressure: Ideal for systems with pressures exceeding 300 bar.
Durability and reliability: Thanks to their robust design, they are less prone to failure under demanding conditions.
Versatility: They can be manufactured in various sizes and shapes to suit different applications, including highly corrosive fluids used in alkylation processes.

Common Applications

Spiral wound gaskets are widely used in:

Petrochemical industries: For sealing flanges in pipelines and reactors.
Power plants: In steam generators and heat transfer systems.
Refineries: In equipment such as heat exchangers and distillation columns.
Marine industry: In propulsion systems and fuel handling applications.

Selecting and Maintaining Spiral Wound Gaskets

When selecting a spiral wound gasket, consider the following:

The system’s temperature and pressure range.
The chemical compatibility of the material with the fluid or gas.
The dimensions of the flanges and the equipment specifications.

Regular maintenance is crucial for maximizing the lifespan of these gaskets. Inspect and replace worn or damaged gaskets to prevent leaks and system failures.

Conclusion

Spiral wound gaskets are indispensable in many industries due to their ability to handle extreme conditions with reliability and efficiency. If you’re seeking solutions for demanding systems, these gaskets offer the perfect balance between strength and flexibility.

Kempchen-Comdiflex manufactures spiral wound gaskets in Spain, tailored to any dimensions, designs, and compositions to meet your specific needs.

WE ARE MANUFACTURERS

ANY DESIGN WITH A LARGE QUANTITY OF MATERIALS

Technical Catalogue