Identifying the type and size of a mechanical seal is crucial for proper maintenance and replacement.
This article will discuss the steps to identify a mechanical seal correctly.
Gather Information About the Existing Seal
Gather information includes locating any part numbers, model numbers, or other identifying information on the seal itself.
It’s also important to note the make and model of the pump that the seal is used in. This information can help narrow down the specific type of seal needed.
If you don’t have any information about existing mechanical seal, you can still identify some of the components by following these steps.
Indentifying Mechanical Seal
Step 1. Types of Spring
- Single Spring: These are used in single mechanical seals and are characterized by their single spring.
- Multi-Spring: These seals use multiple small springs to provide a uniform load across the seal face.
- Wave Spring: Made from flat wire with a wavy profile, wave springs offer high force in a compact space. They are often used when axial space is limited.
- Bellows Spring (Metal or Elastomer): Some mechanical seals use a bellows setup either in metal or elastomer form instead of conventional springs. This design inherently adjusts to pressure variations and wear, providing a uniform load across the seal face without the use of discrete springs.
- Belleville washers: Also known as conical or disc springs, Belleville washers have a conical shape. They provide high loads in a small space and are stackable to achieve desired force characteristics.
- Elastomeric springs: Made from rubber or other elastomeric materials, these springs provide a closing force and accommodate misalignment or vibration. They are commonly used in lower-pressure and less-demanding applications.
Step 2. Types of Seal Face
| Material | Color | Texture | Other Visual Characteristics |
|---|---|---|---|
| Carbon Graphite | Black to dark gray | Matte, slightly rough | Opaque, porous appearance |
| Silicon Carbide | Black, dark gray, or green | Granular, slightly rough | Opaque, may have iridescence |
| Tungsten Carbide | Gray to silver-gray | Smooth, polished | Metallic luster, opaque |
| Ceramic (Alumina) | White, off-white, or ivory | Smooth, glossy, or matte | Opaque, may be translucent |
| Silicon Nitride | Gray, black, or brown | Smooth, matte, or slightly rough | Opaque |
| Stainless Steel | Silver, gray or metallic | Smooth, polished, or brushed | Shiny, metallic luster |
| Bronze | Reddish-brown, golden | Smooth, polished | Metallic luster, may patina |
| Stellite | Silver-gray to blue-gray | Smooth, polished | Metallic luster, opaque |
Step 3. Types of Elastomer
- Nitrile (NBR): Typically black, this elastomer has a smooth, matte surface.
- Fluorocarbon (FKM): Commonly found in black or brown, fluorocarbon elastomers like Viton have a smooth, glossy surface.
- Ethylene Propylene (EPDM): Usually black, though also available in white or gray, EPDM has a slightly rough, matte surface.
- Perfluoroelastomer (FFKM): These elastomers, such as Kalrez or Chemraz, are often black or gray with a smooth, matte surface.
- Silicone: Typically translucent or white, silicone elastomers have a smooth, glossy surface.
- Neoprene: Neoprene is black and features a smooth, matte surface.
Step 4. Types of Metallurgy
Seals are commonly crafted from brass or bronze, along with 304 or 316 Stainless Steel. Monel serves in seawater environments, while Hastelloy excels in high-temperature applications.
Measuring Mechanical Seal
Outer Diameter and Inner Diameter of Stationary Face
Thickness（Height） of Stationary Face
Outer Diameter and Inner Diameter of Rotating Face
Height
In conclusion
Identifying a mechanical seal is a straightforward process that requires careful observation and measurement.
By following the steps outlined in this article, you can accurately determine the type and size of the seal needed for your application.
For more information on mechanical seals and their maintenance, visit our website or contact our expert team today.
