Description of Large-Diameter Seal

Large-diameter seals are specialized components used to create a barrier between different mediums in machinery and equipment, particularly where there are significant gaps or large openings that need sealing. They are designed to contain fluids, gases, or contaminants within a system while also preventing the ingress of unwanted substances. Large-diameter seals come in various shapes, sizes, and materials to accommodate diverse industrial applications.

Large-diameter seals are defined by their size, typically characterized by their outer diameter (OD), inner diameter (ID), and thickness. The specific size requirements depend on the application and the dimensions of the machinery or equipment being sealed. While there is no fixed threshold for what constitutes a "large" diameter seal, they are generally considered to have dimensions larger than standard seals, which typically outer diameters range from 500 mm up to 3000 mm. In some cases also more than 3000 mm outer diameter for special industrial applications.

So, while split seals and one-piece seals differ in their design and construction, they can still be manufactured using similar methods, with the distinction lying in the additional step required for creating the split in split seals.

CV Technik Large Diameter Seal Offerings

Various Elastomer Compounds
Cotton Fabric impregnated elastomers
Metal to rubber bonded items
Polyurethane & Polyamide products

SEAL DIAMETER UP TO 3000 MM - IN ONE PIECE

SEAL DIAMETER > 3000 MM - IN SPLIT FORM

INJECTION MOLDED SEAL DIAMETER UP TO 1500 MM

Types of Large-Diameter Seal

One-Piece Seal: One-piece seals are typically manufactured using methods such as injection molding, compression molding, extrusion, or machining, depending on the material and complexity of the seal design. For example, elastomeric seals like O-rings or lip seals are often produced through injection molding or extrusion, while metallic seals may be machined from solid stock material.

Split Seal: Split seals are usually manufactured using methods such as molding or machining, with an additional step to create the split or separation in the seal. For instance, a split seal may be produced by molding or machining the seal as a single piece, and then cutting or dividing it into two or more pieces along a specific axis or pattern.

The suitability of manufacturing methods for large-diameter seals often depends on the production volume. Here's a breakdown:

High Volume Production:
- Injection Molding: This method is highly suitable for the high-volume production of large-diameter seals. It offers fast cycle times, high repeatability, and low labor costs per unit. Injection molding allows for the production of large quantities of seals with consistent quality.
- Extrusion: For large-diameter seals with uniform cross-sections, extrusion is a cost-effective option for high-volume production. It offers continuous processing and can produce long lengths of seals that can be cut to size as needed.
Medium to Low Volume Production:
- Compression Molding: Compression molding is suitable for medium to low-volume production of large-diameter seals. It offers flexibility in design and material selection, making it ideal for producing seals with complex shapes or varying hardness.
- Transfer Molding: Similar to compression molding, transfer molding is suitable for medium to low-volume production. It provides greater control over material flow and can produce seals with intricate designs and varying material properties.
- Machining: Machining is suitable for producing large-diameter seals in medium to low volumes, especially when precision is paramount or when working with hard materials such as metals or engineering plastics.
Custom or Prototyping:
- Machining: Machining is often used for custom or prototype seals, regardless of volume, due to its versatility and ability to produce seals with complex designs or from various materials.
- Bonded Seals: Bonded seals may be suitable for custom or low-volume production, especially when specific combinations of materials or properties are required.
Hybrid Approaches:
- Combination of Methods: In some cases, a combination of manufacturing methods may be used to optimize production efficiency and meet specific requirements. For example, a manufacturer may use injection molding for high-volume production of standard seals but switch to machining for custom or low-volume orders.

Overall, the choice of manufacturing method for large-diameter seals depends on factors such as production volume, design complexity, material requirements, lead time, and cost considerations. Manufacturers often evaluate these factors to determine the most suitable method for their specific needs.

This video from the Freudenberg Group demonstrates the safe and effective installation of large diameter radial shaft seals. It provides clear steps for handling these seals, along with instructions on preparatory tasks, lead-in chamfers, and housing design. Suitable for various applications such as wind turbines, ship propulsion, steel and paper mills, steel water constructions, and power transmission.