1. What is Nominal Pipe Size (NPS)?

Nominal Pipe Size (NPS) is a North American standard for pipe sizes that provides a standardized way to refer to pipe dimensions. It's important to note that NPS is not exactly equal to either the inside or outside diameter of the pipe.

2. How Does the Calculator Work?

The calculator uses the approximate formula:

Where:

• \( OD \) — Outer Diameter (inches)
• \( \text{wall\_thickness} \) — Wall thickness (inches)

Explanation: This formula provides an approximate calculation of Nominal Pipe Size based on the outer diameter and wall thickness. For precise applications, consult standard pipe size tables.

3. Importance of NPS Calculation

Details: Accurate pipe size identification is crucial for proper pipe selection, fitting compatibility, flow rate calculations, and system design in plumbing, HVAC, and industrial applications.

4. Using the Calculator

Tips: Enter the outer diameter and wall thickness in inches. Both values must be positive numbers. The result provides an approximate NPS value.

5. Frequently Asked Questions (FAQ)

Q1: Why is this an approximate calculation?
A: The relationship between OD, wall thickness, and NPS varies by pipe schedule and material. This formula provides a general approximation.

Q2: What are common NPS sizes?
A: Common NPS sizes include 1/8, 1/4, 3/8, 1/2, 3/4, 1, 1½, 2, 3, 4, 6, 8, 10, 12 inches and larger.

Q3: How does NPS relate to pipe schedules?
A: Pipe schedule (e.g., Schedule 40, 80) indicates wall thickness. The same NPS can have different ODs and IDs depending on the schedule.

Q4: When should I consult standard pipe tables instead?
A: For critical applications, precise engineering calculations, or when working with specific pipe materials and standards.

Q5: Does this work for all pipe materials?
A: The formula provides a general approximation that works reasonably well for many common pipe materials including steel, copper, and PVC.