Hydraulic Fittings Cheat-Sheet

Automotive Lift Repair Florida Hydraulic fittings come in various shapes to connect hoses and components, change 

direction, or split and combine fluid. Common shapes include:

    • Straight Fittings: Simple design for connecting hoses or components in a straight line.
    • Elbow Fittings: Bent or angled design for changing direction, available in various angles.
    • Tee Fittings: T-shaped for splitting or combining fluid flow, connecting three hoses or components.
    • Cross Fittings: Cross-shaped for connecting four hoses or components, enabling complex configurations.
    • Flange Fittings: Used to connect to flanged surfaces, providing secure, leak-free connections for high-pressure applications.
  • Material: Hydraulic fittings are made from various materials depending on industry needs:
    • Steel: Offers strength and durability, suitable for a wide temperature range.
    • Stainless Steel: Corrosion-resistant and durable, used in harsh environments and high-pressure applications.
    • Plastic: Corrosion-resistant but less durable and not suitable for high-pressure or temperature conditions.
    • Brass: Good corrosion resistance and meets various standards, but less durable than stainless steel.
    • Aluminum: Lightweight and corrosion-resistant, used mainly in the automotive industry for its strength-to-weight ratio.

Choosing the Right Hydraulic Hose Fitting

Selecting the appropriate Automotive Lift Repair Florida hydraulic hose fitting is essential for ensuring the efficiency and safety of your hydraulic system. Key factors to consider include size, material, temperature range, pressure requirements, and the specific needs of your application. For fittings that need frequent connection and disconnection, choose ones that are easy to assemble and disassemble. Proper selection helps maximize productivity and minimize downtime.

Hydraulic fittings are essential for connecting hoses, pipes, and tubes to components such as hydraulic manifolds, cylinders, and other equipment—something you probably already know if you’re reading this blog! But did you realize there are various types and applications for hydraulic and some pneumatic fittings?

1. NPT (National Pipe Taper) and NPS (Nominal Pipe Size) Fittings: Featuring a 60° thread angle with flattened crests and roots, these fittings have been popular in North America for over a century. NPT male threads create a mechanical wedge when paired with female threads, effectively crushing the threads together. They’re widely used in construction, agriculture, industrial equipment, plumbing, and automotive applications.

2. Automotive Lift Repair Florida JIC (Joint Industry Council) SAE J514 Fittings: These compression fittings are highly regarded in fluid power systems. Their 37° flare seating surface uses straight, parallel threads rather than tapered threads or O-rings to form a seal. Capable of withstanding up to 10,000 PSI, they’re common in aerospace, military, automotive, construction, agricultural, and heavy equipment industries.

3. ORB (O-ring Boss) Fittings: Also known as SAE J1926 Straight Thread O-ring Boss fittings, these use straight threads and an O-ring located at the base of the male thread to seal. The O-ring seals between the male fitting and a machined seat in the female port, providing a leak-tight connection. They’re used across various industries for fluid transfer, especially where a secure seal is crucial.

4. Automotive Lift Repair Florida ORFS (O-ring Face Seal) Fittings: Featuring an O-ring recessed into the fitting face, these are ideal for hydraulic systems subject to vibration and impulse. They handle pressures up to 6,000 PSI and are commonly used in off-road, construction, agricultural, petrochemical, and shipbuilding industries.

5. Tube Fittings and Adapters: This category includes various connections like NPT, JIC, and O-Ring Boss fittings, as well as adapters, caps, and plugs. They facilitate connections from hose barbs to NPT or JIC SAE 37° reducers, among others.

6. Flanges: Typically ranging from ½” to 2″ in size, flanges connect pipes, valves, pumps, and other equipment subjected to high pressure and vibration. SAE Code 61 flanges are used for lower pressures (3,000 to 5,000 PSI), while Code 62 is used for higher pressures (up to 6,000 PSI). Caterpillar OEM equipment uses unique 4-bolt flanges that are not interchangeable with SAE flanges due to differences in thickness.

7. Instrumentation Fittings: Also known as compression fittings, these are used in control and process measurement systems, as well as cryogenic applications. They come in single or double ‘bite-type’ ferrules and are designed to connect tubing for gas or liquid transfer. The fittings consist of a body, nut, and ferrule, which ensure a leak-free connection when assembled. They can handle temperatures from cryogenic to very high heat, depending on tubing specifications.

8. Automotive Lift Repair Florida BSP (British Standard Pipe) Fittings: Popular in the UK, BSP fittings are extensively used by manufacturers like JCB. They have unique seat and thread angles that should not be confused with other fittings. BSP male fittings feature a 30° conical seat that mates with a corresponding 30° conical female seat. BSPP fittings have parallel threads and seal with an O-ring or bonded washer, while BSPT fittings have tapered threads that create a metal-to-metal seal, often requiring thread sealant.

9. The fitting body has a 24° tapered throat where tightening the nut presses a ferrule into the tube.

10. Flare-O Fittings: Incorporating a SAE 37° flare to NPT adapters, these fittings use an elastomeric O-ring seal for a leak-free connection and are suitable for high temperature and pressure applications.

11. Weld Fittings: Used to join components to pipes, hoses, or other fittings, these offer extra protection against leaks and are essential for structural integrity or permanent connections in ASME pipe applications. They are also used in conveying toxic or flammable substances.

12. Automotive Lift Repair Florida Metric Fittings: Predominantly used in Europe and Asia, these fittings come in several styles. Metric DIN 2353 fittings, widely used globally, establish a seal by tightening the nut on the male fitting, which wedges the bite sleeve onto the standpipe tube without needing an O-ring. JIS (Japanese Industrial Standard) metric hydraulic fittings are used mainly in Japan and Asia, with specific styles like Komatsu’s 30° flare fitting providing superior performance in their heavy equipment.

13. Push-to-Connect Fittings: Typically made of nickel-plated brass or glass-reinforced thermoplastic, these fittings allow quick connection and release by pushing the collar back and sliding the tube into the fitting. They’re commonly used in water, air, and Automotive Lift Repair Florida pneumatic systems, as well as in D.O.T. air brake systems for large vehicles. Various adapters are available for different applications.