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NFPA Cylinders

By Jeff Bready, CFPS

In many pieces of industrial how and mobile equipment, cylinders are used to provide linear or straight-line motion and force. Several decades ago, industry manufacturers adopted standards for the common features of these linear actuators, such as port sizes and locations, mounting dimensions and mounting styles, bore and rod diameter combinations, and piston seal types. These standard qualities, referred to as NFPA (National Fluid Power Association) Standards, allow for the easy interchange of cylinders from one manufacturer to another. This means that one manufacturer’s cylinder can be directly and simply replaced by the same NFPA-style cylinder from another vendor.

NFPA industry-standard cylinders are available in many types, including aluminum, steel, and stainless steel, and in both hydraulic and pneumatic versions. NFPA standard cylinders, also commonly referred to as JIC (Joint Industry Council) cylinders, are constructed with square end caps and held together with four tie rods. The manufacturers of these NFPA cylinders use the common standard mounting dimension for each of the various mounting styles, which means that the user has the flexibility to obtain an NFPA standard cylinder anywhere in the world.

Typical pneumatic cylinders can operate in systems of up to 250 psi, while hydraulic cylinder pressure ratings depend on the bore and rod combination selected but can be rated up to 5000 psi system pressure. Prior to applying a cylinder in a system, many pieces of information need to be gathered. Quality Hydraulics can help you in defining the specifics of your application and in determining which cylinder best suits your design.

The application-specific characteristics required include:
•    Force required
•    Linear distance of travel
•    System cycle time preferred
•    System pressure available
•    System fluid (or air) to be utilized
•    Ambient and system temperatures expected
•    Presence of caustic or corrosive environment
•    Special or standard materials required – including cylinder construction as well as seals required
•    Optimum bore and rod combination to provide necessary force and travel
•    Cylinder performance requirements such as cushions or electronic feedback
•    Cylinder mounting considerations
•    Other external physical considerations such as side loading
•    Port sizing for appropriate flow required
•    Any plumbing or piping concerns
•    Any other unusual considerations appropriate to the specific application

After all the specific application requirements and considerations have been determined, the best NFPA standard cylinder for the job can be selected.

Quality Hydraulics & Pneumatics, Inc., is an authorized distributor of various NFPA standard cylinders in different areas of the region. Quality Hydraulics is the authorized distributor of both Hydro-Line cylinders and Nason cylinders in Illinois, Iowa, and Indiana. We are also a distributor of Vickers cylinders in Iowa.