ORB Fitting vs NPT: The Comparison Guide

ORB Fitting vs NPT Fitting
Looking to choose between NPT fitting and ORB fitting? Read our detailed comparison of ORB fitting vs NPT fitting, including size differences, installation tips, and applications.

Table of Contents

In the world of hydraulic systems, selecting the correct type of fitting is crucial for the functionality, safety, and efficiency of the entire setup.

One common comparison is ORB fitting vs. NPT fitting. These two types of fittings are often used in different applications, and understanding their differences can help you make an informed decision about which one best suits your needs.

If you have any questions or need assistance, feel free to contact us directly.

What are NPT Fittings?

ORB Fitting vs NPT Fitting what are npt fitting

NPT, or National Pipe Tapered, is a widely used thread standard for pipe fittings in the U.S. These fittings are designed to create a seal by tapering the threads, ensuring that they tighten as they are screwed together, creating a pressure-tight seal.

Structure of NPT Fittings:

  • NPT fittings feature a tapered thread design, meaning the threads become tighter as the fitting is installed, leading to a self-sealing effect.
  • The seal is achieved through thread contact and compression, making them ideal for applications involving liquid or gas pressure.

Common NPT Fitting Sizes

(Note: These sizes are commonly used and suitable for various industries, especially in fluid and gas systems):

NPT Size (in inches)Outer Diameter (OD)Thread Pitch (TPI)
1/8″0.405″27
1/4″0.540″18
3/8″0.675″18
1/2″0.840″14
3/4″1.050″14
1″1.315″11
1 1/4″1.660″11

Applications and Features of NPT Fittings

Applications of NPT Fittings

Commonly used in plumbing, natural gas lines, and other fluid-based applications.

They are suitable for both high and low-pressure systems but require proper sealing techniques to avoid leakage.

Available in various materials like steel, stainless steel, brass, and plastic.

Often used in industrial, automotive, and domestic systems.

Features of NPT Fittings

One of the main advantages of NPT fittings is their ease of installation. Due to their tapered threads, they can be easily tightened by hand initially and then further tightened with a wrench to achieve a proper seal. Another advantage is their wide availability.

They are a standard in the industry, so finding replacement parts or compatible components is relatively straightforward. However, one drawback is that the tapered threads can sometimes make it difficult to achieve a perfect seal on the first try, especially in high-pressure applications. This may require some additional effort, such as using thread sealant.

What are ORB Fittings?

ORB Fitting vs NPT Fitting what are orb fitting

ORB, or O-Ring Boss, is another popular fitting style used in hydraulic systems. ORB fittings are designed to create a seal using an O-ring that compresses against a flat surface. This allows for a more reliable seal, especially under high-pressure conditions.

Structure of ORB Fittings:

  • ORB fittings feature a straight thread design and rely on an O-ring placed in a groove to provide the sealing.
  • These fittings do not use the tapered threads seen in NPT fittings. Instead, the seal is created by the O-ring compressing against a flat surface when the fitting is tightened.

Common ORB Fitting Sizes:

ORB fittings come in similar sizes to NPT, but they differ in their thread style. The following are typical ORB sizes (measurement units in inches):

ORB Size (in inches)Outer Diameter (OD)Thread Pitch (TPI)
1/8″0.405″27
1/4″0.540″18
3/8″0.675″18
1/2″0.840″14
3/4″1.050″14
1″1.315″11
1 1/4″1.660″11

Applications and Features of ORB Fittings

Applications of ORB Fittings

Commonly used in high-pressure hydraulic systems where a more reliable seal is required.

Due to the O-ring, ORB fittings offer better sealing capabilities and are more resistant to leakage compared to NPT.

Often used in industries that require high-pressure operations like automotive, construction, and heavy machinery.

Features of ORB Fittings

The main advantage of ORB fittings is their excellent sealing performance. The O-ring provides a positive and reliable seal, even in high-pressure and high-vibration environments. The straight-thread design also makes them easier to assemble and disassemble compared to some other types of fittings.

Additionally, the use of O-ring allows for a relatively quick and simple replacement in case of damage. However, ORB fittings can be more expensive than NPT fittings, and the O-ring needs to be carefully selected and maintained to ensure proper sealing.

ORB Fitting vs NPT Fitting: Key Differences

orb vs npt Fittings

Now, let’s take a closer look at the differences between NPT and ORB fittings across various aspects.

Design:

  • NPT: Tapered thread design. As the threads tighten, they create a seal through compression. This can sometimes lead to leakage if not properly installed.
  • ORB: Straight threads combined with an O-ring that seals against a flat surface. This design is more reliable and prevents leakage, especially under high pressure.

Size and Thread Types:

  • Both NPT and ORB fittings come in a variety of sizes, but their thread types differ significantly. NPT fittings feature tapered threads, while ORB fittings have straight threads with an O-ring for sealing.

Materials:

  • Both types of fittings are made from materials like steel, brass, and stainless steel, but ORB fittings are often preferred for applications that involve higher pressures.

Applications:

  • NPT: Suitable for general plumbing, gas lines, and low-pressure systems. However, it’s important to note that proper sealing is crucial for NPT fittings to work efficiently.
  • ORB: Commonly used in hydraulic systems that require higher pressure and where leakage could result in serious issues. The O-ring design offers superior sealing.

Installation:

  • NPT: Requires careful installation to achieve a proper seal. Over-tightening can lead to damage, and under-tightening may cause leaks.
  • ORB: Easier to install because the O-ring ensures a tight seal once the fitting is tightened, making it more forgiving during installation.
Comparison AspectNPTORB
DesignSimilar; favored for high-pressure due to O – ringTapered threads; seals by compression, leakage risk if mis-installed
Thread TypeTaperedStraight
MaterialsSteel, brass, stainless steelHigh-pressure hydraulic systems, critical – leak – prevention setups
ApplicationsGeneral plumbing, gas, low – pressure systemsEasier, O-ring eases installation
InstallationPrecise; over/under – tightening issuesPrecise; over/under-tightening issues

Can They Be Interchanged?

No, NPT fittings and ORB fittings are not interchangeable.

Due to their different thread designs (tapered vs. straight) and sealing mechanisms (compression vs. O-ring), they are not compatible with each other.

How to Choose Between NPT and ORB Fittings

ORB Fitting vs NPT Fitting npt fitting

Step 1: Assess the Pressure Requirements
If your system operates under high pressure, ORB fittings are likely a better choice due to their superior sealing capacity. If your system operates under lower pressure, NPT may suffice.

Step 2: Consider the Application
For plumbing and low-pressure applications, NPT fittings can be more economical and sufficient. For hydraulic systems, heavy machinery, and high-pressure operations, ORB fittings are ideal.

Step 3: Evaluate the Need for Easy Installation
If ease of installation and a reliable seal are critical, ORB fittings are a better option due to the O-ring’s ability to create a seal without worrying about thread tightening.

Step 4: Check for Compatibility
Ensure that your system is compatible with the chosen fitting type, as NPT and ORB fittings cannot be used interchangeably.

Summary of Key Considerations

  • NPT fittings are best for general applications, but they require careful installation to prevent leaks.
  • ORB fittings are designed for higher pressure systems and provide better sealing through the use of an O-ring.
  • While both fittings come in similar sizes, their sealing mechanisms, thread designs, and applications differ.
  • Always choose fittings based on your system’s pressure needs, application, and ease of installation requirements.

Conclusion

In conclusion, when choosing between ORB fitting vs NPT fitting, it’s essential to evaluate your system’s pressure requirements, installation needs, and application type.

While NPT fittings are suitable for general applications, ORB fittings are ideal for hydraulic systems that require superior sealing and high-pressure operation.

If you have further questions or need assistance, feel free to contact us. If you’re interested in our products, visit our homepage or request our product catalog.

FAQs About ORB Fitting vs NPT Fitting

Is ORB the same as NPT?

No, ORB and NPT are different. ORB uses straight threads and an O-ring for sealing, while NPT features tapered threads that create a seal through compression. They are not interchangeable.

When should you use an ORB fitting?

You should use an ORB fitting when working with high-pressure systems, such as in hydraulics, where a tight, reliable seal is necessary.

Are NPT fittings flared?

No, NPT fittings are not flared. They are tapered threads that tighten as they are screwed in, creating a seal through compression. Flared fittings have a distinct angled design, unlike NPT.

What thread type is ORB?

ORB fittings have straight threads, unlike NPT fittings which have tapered threads. The ORB fitting seals using an O-ring against a flat surface.

How tight should ORB fittings be?

The tightness of ORB fittings should be in accordance with the manufacturer’s recommended torque specifications. Over-tightening can damage the O – ring and the fitting itself, leading to leaks. To ensure proper tightness:
Step 1: First, hand-tighten the fitting until it is snug.
Step 2: Then, use a torque wrench to tighten the fitting to the recommended torque value. This value can usually be found in the product documentation provided by the manufacturer. It’s important to note that different sizes and materials of ORB fittings may have different torque requirements.

Where to buy fittings?

For customized fittings, reach out to us at Dingfeng. We offer a full range of hydraulic fittings and accessories. Contact us today or visit our website to find the perfect solution for your needs.

Share to:

Contact us

Looking to buy our products?