Unveiling the Secrets: A Comprehensive Guide on How to Measure Compression Fitting Size

Compression fittings are an essential part of any hydraulic system, providing a secure and leak-free connection between pipes and components. To ensure a proper fit, it’s crucial to accurately measure the compression fitting size before making a purchase. This guide will walk you through the steps involved in measuring compression fitting size, helping you achieve a successful installation.

Identifying the Compression Fitting Type

Before measuring, it’s important to identify the type of compression fitting you’re dealing with. Compression fittings come in various styles, including:

• Single Ferrule: Utilizes a single ferrule to compress the pipe.
• Double Ferrule: Employs two ferrules to provide a tighter seal.
• Inverted Flare: Involves flaring the pipe outward to create a seal against the fitting.

The type of compression fitting will determine the specific measurements you need to take.

Measuring the Pipe Outside Diameter (OD)

The pipe outside diameter (OD) is the first measurement you’ll need to take. This is the diameter of the pipe itself, not including any threads or fittings. To measure the pipe OD, use a caliper or a micrometer.

Position the caliper or micrometer jaws around the pipe, ensuring they are perpendicular to the pipe axis. Gently squeeze the jaws until they make firm contact with the pipe surface. Read the measurement on the caliper or micrometer display.

Measuring the Compression Fitting Bore Size

The compression fitting bore size refers to the inner diameter of the fitting where the pipe will fit. This measurement is typically indicated on the fitting itself or in the manufacturer’s specifications. If not specified, you can use a caliper or a bore gauge to measure the bore size.

Insert the caliper or bore gauge into the fitting bore, ensuring it makes contact with the inner surface. Gently move the caliper or bore gauge around the bore to obtain the most accurate measurement.

Measuring the Compression Fitting Length

The compression fitting length is the distance from the end of the fitting to the shoulder where the pipe will seat. This measurement ensures that the fitting will extend far enough into the pipe to create a secure seal. To measure the compression fitting length, use a ruler or a tape measure.

Place the ruler or tape measure along the fitting, starting from the end of the fitting and extending to the shoulder. Read the measurement on the ruler or tape measure display.

Measuring the Ferrule Size

The ferrule is a metal ring that compresses the pipe against the fitting bore. The ferrule size is typically indicated on the ferrule itself or in the manufacturer’s specifications. If not specified, you can use a caliper or a micrometer to measure the ferrule size.

Position the caliper or micrometer jaws around the ferrule, ensuring they are perpendicular to the ferrule axis. Gently squeeze the jaws until they make firm contact with the ferrule surface. Read the measurement on the caliper or micrometer display.

Verifying the Measurement

Once you have taken all the measurements, it’s important to verify them to ensure accuracy. Compare the measurements to the manufacturer’s specifications or use a sizing chart to confirm that the compression fitting size is compatible with your pipe and application. If the measurements are incorrect, repeat the measuring process to ensure precision.

Choosing the Right Compression Fitting Size

With the accurate measurements in hand, you can now choose the correct compression fitting size. Select a fitting that matches the pipe OD, compression fitting bore size, and compression fitting length. Ensure that the ferrule size is also compatible with the pipe OD. By following these steps, you can ensure a perfect fit for your compression fitting, guaranteeing a secure and leak-free connection.

Key Points: Getting It Right the First Time

Measuring compression fitting size accurately is essential for a successful installation. By following the steps outlined in this guide, you can ensure that you choose the right fitting for your application. Remember to verify your measurements, refer to manufacturer’s specifications, and use a sizing chart if necessary. With proper measurement and selection, you can achieve a leak-free and reliable connection every time.

Frequently Asked Questions

Q: What is the difference between a single ferrule and a double ferrule compression fitting?

A: Single ferrule fittings use a single ferrule to compress the pipe, while double ferrule fittings utilize two ferrules for a tighter seal.

Q: How do I measure the pipe outside diameter (OD) if I don’t have a caliper or micrometer?

A: You can use a ruler or a tape measure to wrap around the pipe. Mark the point where the ends of the ruler or tape measure meet, then measure the distance between the marks.

Q: Why is it important to verify the measurements before choosing a compression fitting size?

A: Verifying the measurements ensures that you choose the correct fitting for your application. An incorrect fit can lead to leaks or connection failures.