Pipe elbows, crucial components in piping systems, are measured primarily by their nominal pipe size (NPS) and their radius. Let's explore these measurements in detail.
Nominal Pipe Size (NPS)
The NPS isn't a direct measurement of the inside diameter but a standard designation for pipe sizes. It's commonly used to identify elbow dimensions and is often the same as the outside diameter of the pipe. This standardization simplifies ordering and installation. You'll typically see NPS denoted as numbers (e.g., 1", 2", 6").
Radius and Center to Center Measurement
The radius of an elbow refers to the radius of the arc formed by the elbow's center. This is a critical dimension for fitting the elbow into the piping system. Elbows are often described as having a long radius or a short radius. This radius directly influences the overall length of the elbow.
A crucial related measurement is the center-to-center distance between the pipe ends connected by the elbow. For a 90° elbow, this measurement is directly related to the elbow's radius.
Calculating 90° Elbow Length
A 90° elbow's length can be easily calculated using a simple formula:
- Fitting length = 1.5 x NPS
For example: A 2" NPS 90° elbow would have a length of approximately 3 inches (1.5 * 2"). This formula is an approximation, and actual dimensions may vary slightly depending on the manufacturer and the specific elbow type.
Other Important Considerations:
- Wall Thickness: While not directly a measurement of the elbow itself, the pipe wall thickness affects the overall outside diameter and, consequently, the space needed for installation.
- Materials: Different materials (steel, PVC, etc.) can have slightly different dimensional tolerances.
- Standards: Elbows are manufactured to various industry standards (e.g., ASME B16.9), influencing their exact dimensions.
