Choosing an inappropriate type of pipe connection may cause severe leakages in the connection area. Thus, consider the pipe types and application sector before choosing the pipe coupling types. Nowadays, pack joints and compression fittings are two important pipe connection types in the market.
But what is the difference between pack joint vs compression fitting? The first one is cheaper, easier to install, and reusable. But the latter one is suitable for high-pressure and purity applications, whereas you can use the former one only in low-pressure applications.
Throughout this article, we will discuss the comparison between them in detail. At the end of the article, it will be easier for you to decide which one is the best fit for you. Now, without further ado, let’s go through the article.
Differences Between The Pack Joint And Compression Fitting
Let’s see some key differences between these two pipe coupling elements in the table below.
| Parameters | Pack Joint | Compression Fitting |
| Design | Major parts: fitting body, gasket, compression nut, and clamp grip | Major parts: nut, a fitting body, and a ferrule |
| Sealing | The gasket acts as a sealing component | Ferrule work as a sealing component |
| Compatibility | Compatible with copper, galvanized steel, PVC, and CPVC pipes | Compatible with copper, brass, and Teflon pipes |
| Ease of installation | Easy | Complex |
| Reusability | Can be reused | Can be reused but hardly |
| Pressure tolerance | Low-moderate | Low-high |
| Price | $20-$200 | $10-$340 |
| Applications | Potable water distribution lines | Higher pressure and purity sectors |
Pack Joint Vs Compression Fitting: In-Depth Comparison
Here is an in-depth comparison between the pack joint and compression fitting:
Design
Generally, the design of the pack joint consists of vital parts like the fitting body, gasket, compression nut, and clamp grip. After inserting the tube inside the fitting, you need to tighten the nut to provide adequate pressure on the gasket. When you tighten the clamp grip, the tube will restrain.
On the other hand, compression fittings consist of 3 main components- a nut, a fitting body, and a ferrule. In this case, you need to insert the tube into the fitting end. Make sure you are tightening the nut enough to squeeze the ferrule between the tubing and the fitting body.
Sealing
In the case of pack joints, the gasket works as the main sealing component. When the nut presses the gasket down on the tube, the gasket will create a watertight sealing.
But normally, the sealing capability of compression fitting will depend on the ferrule. Typically, the material and shape of the ferrule will play a vital role in deciding how reliable the seal will be.
Suitability
Pack joints are pretty versatile as you can use them with copper, galvanized steel, PVC, and CPVC pipes. But the compression fittings are mainly suitable for metal and hard plastic tubings.
As the pressure that this type of fitting applies is greater than the pack joint, it will require more robust pipes. Normally, copper, brass, and Teflon pipes will be suitable for this type of fittings.
Ease Of Installation
The installation process of the pack ring will require just tightening the nut with a simple wrench. But in the case of the compression fitting, you must know about the installation process. That’s because the tightening level and the alignment of the ferrule will impact the sealing reliability a lot.
Besides, you may need to use a little amount of oil or grease on the fitting’s thread. This will reduce the torque requirements for proper sealing.
If the relative angle of the fitting body and the ferrule isn’t proper, you can’t create adequate linear contact compression around the ferrule. Also, both tightening and over-tightening will contain the potential risk of a water leak.
Check this Youtube video to visualize the installation process of the compression fitting:
Reusability
You can disassemble the joint coupling just by loosening the compression nut. Thus, it’s also quite easy to clean, maintain and even fix this joint. After cleaning or repairing, you can reassemble the joint in the same way as before easily.
But you can’t reuse the compression fitting once you remove them. Also, as the ferrule grips the pipe tightly, it’s difficult to disassemble the fitting without damaging it.
Due to compression, the ferrule gets deformed and sometimes also deforms the plastic tubing. As a result, if you want to reuse this fitting, you need to replace the ferrule and the deformed tubing with new ones.
Pressure Tolerance
The pack joint can’t withstand extreme pressure. Thus, if you use them in a higher-pressure application, there is a high risk of leakage. But the compression fitting is suitable for pressure up to 3500kPa depending on the media and pipe size.
But in this case, make sure you are using robust fitting components. Similarly, these fittings can also provide a good seal at lower pressure.
Price
The price of the compression fittings will be higher than that of the joint. Normally, you can buy a pack joint for one end by spending around $20-$200. But the price of the compression fitting may vary in the range of $10-$340 depending on the type and material of the fitting.
Applications
You can’t use the pack joint in any steam system. Usually, you can use them in underground and potable water distribution service lines.
On the other hand, you can use compression fittings in hydrogen fuel cells, aerospace, gas lines, and high-pressure water lines. Also, this fitting is applicable in high-purity sectors like semiconductors, petrochemical, instrumentals, and medical industries.
Which One To Choose Between Pack Joint And Compression Fitting?
Both of these pipe coupling elements are best in their place. Which one you need to choose will entirely depend on your perspective. If you are looking for a pipe connection for soft metal or plastic pipes, you can choose a pack joint.
However, pack joints are easy to install and come in a lower price range. Though they don’t provide an excellent seal as the compression fittings, they are good enough for low or moderate-pressure sector applications.
But if you want to use the coupling element for more critical conditions, you should be concerned about the sealant quality. In this case, the compression fittings will be a better choice though it comes in a higher price range.
FAQs
In this FAQs section, we will answer several familiar questions about compression fitting and pack joints.
If you over-tighten the nut, the ferrule will get deformed excessively and will develop surface contact. But the more the surface contact is, the weaker the seal it will form.
Yes. While employing this joint in any softer plastic material, you need to use a metal stiffener inside the pipe to hold the pipe’s structure. Otherwise, the pipe’s structure may collapse and escape from the joint easily.
No. This type of fitting is not very robust for withstanding the vibrational force. Thus, dynamic stresses like sudden shaking, vibration, flexing, or bending may disrupt the integrity of the seal.
Conclusion
For a perfect pipe coupling, you need to ensure the integrity of the seal between the coupling elements and the pipe. There are several pipe coupling elements in the market. Among them, we provided a pack joint vs compression fitting comparison in this article.
According to the comparison, the latter one provides a tight seal and is more reliable in high-pressure applications than the first one. But the first one will be a good option at a cheaper price range with moderate pressure applications.