How to Tell Thread Size on a Plug Pump: A Comprehensive Guide

Understanding the thread size of a plug pump is crucial for selecting the correct pipe or fitting and ensuring a leak-free connection. Whether you're a seasoned plumber or a DIY enthusiast, grasping this concept will help you navigate plumbing projects with confidence.

Measuring Thread Size: A Step-by-Step Guide

Measuring the thread size of a plug pump is a straightforward process that can be broken down into a few simple steps:

1. Identify the Thread Type: Determine if the threads are National Pipe Thread (NPT) or British Standard Pipe Thread (BSPT). NPT threads are tapered, while BSPT threads are parallel.
2. Use a Thread Gauge: A thread gauge is a specialized tool that allows you to check the thread size. Place the gauge over the threads and align the teeth with the crests and valleys. The gauge should fit snugly without any gaps or overlaps.
3. Determine the Nominal Pipe Size (NPS): The NPS is the diameter of the pipe that the plug pump is designed to fit. Refer to the table below for a list of common NPS and their corresponding thread sizes:

4. Check the Pitch: The pitch is the distance between two adjacent threads. You can measure the pitch using a pitch gauge or a ruler. The pitch is typically expressed in threads per inch (TPI).

Why Thread Size Matters

Selecting the correct thread size is crucial for several reasons:

• Leak Prevention: Using a plug pump with the correct thread size ensures a tight seal and prevents leaks.
• Connection Strength: The proper thread size provides sufficient grip to create a strong and secure connection.
• Compatibility: Matching the thread size of the plug pump to the pipe or fitting ensures seamless compatibility and ease of installation.

Benefits of Knowing Thread Size

Understanding the thread size of a plug pump offers numerous benefits:

• Accurate Pipe Selection: You can confidently select the correct pipe or fitting to match the plug pump's thread size.
• Time-Saving Installation: By knowing the thread size beforehand, you can avoid trial-and-error fittings and complete plumbing projects more efficiently.
• Reduced Frustration: Dealing with leaks or incompatible connections can be frustrating. Knowing the thread size eliminates these hassles and ensures a smooth plumbing experience.

Tips and Tricks for Measuring Thread Size

• Use a Clean Plug Pump: Ensure that the plug pump is free of dirt or debris before measuring the thread size.
• Hold the Plug Pump Straight: Hold the plug pump perpendicular to the gauge for an accurate measurement.
• Check Multiple Threads: Measure several threads along the length of the plug pump to ensure consistency.
• Consider a Thread Identifier: If you're unsure of the thread type, a thread identifier can help you distinguish between NPT and BSPT threads.

FAQs

1. What is the difference between NPT and BSPT threads?
   - NPT threads are tapered, while BSPT threads are parallel.
2. What is the most common thread size for plug pumps?
   - 1/2-14 NPT and 1/2-11 BSPT are common thread sizes for plug pumps.
3. How do I convert between NPT and BSPT thread sizes?
   - It is generally not recommended to convert between NPT and BSPT threads due to potential compatibility issues.
4. Can I use a plug pump with a different thread size than the pipe?
   - No, using a plug pump with a different thread size than the pipe can lead to leaks or damage.
5. What is the nominal pipe size (NPS)?
   - The NPS is the diameter of the pipe that the plug pump is designed to fit.
6. What is the pitch of a thread?
   - The pitch is the distance between two adjacent threads, typically expressed in threads per inch (TPI).
7. Why is it important to match the thread size of the plug pump and the pipe?
   - Matching the thread size ensures a tight seal, connection strength, and compatibility.
8. Can I measure thread size with a ruler?
   - While using a ruler can provide an estimate, it is not as accurate as using a thread gauge.

Call to Action

Understanding the thread size of a plug pump is essential for successful plumbing projects. By following the steps outlined in this guide, you can confidently determine the thread size and select the correct pipe or fitting for a leak-free and reliable connection. Remember, accurate thread size measurement ensures a smooth installation and peace of mind. Embrace this knowledge and embark on your plumbing endeavors with confidence.