Everything You Need to Know About Air Cylinders: Types, Working Principles & Uses

Just like any technology air cylinders (pneumatic actuators) have come a long way with innovations. Engineers have developed different designs of air cylinders making them suitable for different applications. This article, is a one stop information center to learn all about air cylinders (pneumatic actuators) in an easy to understand manner. Learn how air cylinders work, their types, applications, benefits, and real world examples of industrial air cylinders.

1. How Do Air Cylinders Work in Automation Systems?

1.1 Basic Working Principle

Have you ever used a bicycle pump? You push the handle and air comes out of the pipe which fills the bicycle tyre. Imagine it the other way around you supply high pressure air into the pipe which will cause the handle to move. Its because the air pushes the disc like element inside the pipe like section. The disc is connected to the handle which will cause the handle to move.

Air cylinders work in a similar way but are much more sophisticated in design with intent to perform with reliability, durability and repeatability. These use high pressure air from compressed air source with typical 0.1 MPa to 1.0 MPa (approximately 14.5 PSI to 145 PSI) pressure. The air enter the port and pushes the piston. The psiton is connected to a rod which causes the rod to move along with piston creating a straight motion. Two end caps are held tightly against the barrel or cylinder tube using tie-rods.

In case we need it to move the other way we provide compressed air to the other port for reverse movement. It consists of following parts:

• Piston

• Rod

• Barrel or Cylinder Tube

• Seals

• End Caps

• Tie Rods

1.2 Single-Acting vs. Double-Acting Mechanisms

The example we showed earlier is the double-acting mechanism of an air cylinder. In case of single-acting there is only one port. As long as compressed air is pushed into the port the cylinder maintains its position forcing the spring from extended to compressed position. As soon as we release the pressure the piston springs back to its neutral or initial position. The whole movement is called single-acting mechanism.

2. What Are Different Types of Air Cylinders Commonly Used?

2.1 Standard Cylinders

There are two key standard types of cylinders. The key distinction between them is their compliance and relevance to International Organization for Standardization (ISO) or National Fluid Power Association (NFPA) standards. Which makes each type suitable for certain regions of the world. Here are their explanations:

2.1.1 Tie-Rod Standard Cylinders

Tie-rod standard cylinders are in-line with the ISO 15552, ISO 6431 or VDMA 24562 standards which are common in Europe and other parts of the world. These focus on repairability and have lighter bodies. Their build allows them to work at higher-speeds with bore sizes varying between 32mm–200mm.

Choose the tie-rod standard cylinders for better compatibility with other systems around the globe. These are great for precison and versatile applications.

Example: Titan Automation's ISO-Standard Cylinders - DNG Series Tie-Rod Pneumatic Cylinders

2.1.2 NFPA Standard Cylinders

Air cylinders that confirm the NFPA standard (NFPA T3.6.7) focus on the North American market. These are also tie-rod construction with standard mounting. They offer standard monting dimensions and interchangeable designs with brands like Parker, Festo, and Bimba. These are heavy in construction making them suitable for heavy duty work with ruggedness. The standard ensures use of corrosion resistant material and offer adjustable air cushion.

Example: Titan Automation's - Professional NFPA Pneumatic Cylinders

2.2 Compact Cylinders

In case where there is space constraint like in automation and robotics, compact cylinders can prove to be useful. There are specialized compact air cylinders that provide unique specifications for diverse applications. Here are the two main types of compact cylinders:

2.2.1 Low-Profile Compact Designs

For ultra space saving low-profile compact air cylinders are ideal. These can have stroke lengths from 5 to 50mm. The round profile and reduced overall heiight makes them great for tight instllatoins. These are greate for robotics and assembly lines where movement matters more than force.

Example: Titan Automation's LP/LPM Series with Through-Hole Mounting

2.2.2 Multi-Force Compact Variants

In case where force matters more within a compact size and small strokes, multi-force compact variants are ideal. These air cylinders may feature multiple pistons in series or parallel to amplify the force. Their large force makes them ideal for heavy-duty pressing.

Example: Titan Automation's SDAT, ADVU and SDAP Series

2.3 Round Cylinders

The round cylinders are compact and offer minimalist design. They are easy to repair and clean making them ideal for light applications where cleanliness is key.

2.3.1 Stainless Steel Round Mini Cylinders

These SS based round mini air cylinders utilize the ISO6432 standard. The corrosion resistant materials enables their application in food or medical settings. Typically they come with foot, flange, or swivel mounting varieties. The simple design also makes them cost effective.

2.3.2 Repairable Round Body Cylinders

For simple linear motion, round pody cylinders are ideal. To make these air cylinders repairable lightweight construction using alumnum is preferd. These are great for packaging and material handling. 

Example: Titan Automation's Nose Mount Aluminum Small Pneumatic Cylinders

Here are specification of a repairable round body air cylinder:

2.4 Two & Three-Rod Cylinders

Using two or three rods to power movements can often be required. In high-tech automation industry use of such stable movements can be key. Using dual rods or more rods for air cylinder means there is no rotation enabling precise linear movements. These can have stroke length of 10-200mm. Within a compact design they can offer shear force resistance.

2.5 Rodless Cylinders

Using a rodless cylinder allows for longer strokes without the needs of protruding rods. Typically they are utlized in conveyors for linear motions. They utilize a magnetic/mechanical coupling for the straight movements. The design allows them to bebuilt in slim profile and feature built-in carriers with rails for stable operation. They do not require lubrucation and can withstand 20M+ cycles. A single stroke can move an object by 6000mm.

3. Air Cylinder Common Applications

4. What Are the Key Benefits of Using an Air Cylinder?

Engineers can induce linear motion using electrical motors but the process is inefficient and sluggish. So they decided to utilize the ultra fast air cylinder motion. They are excellent for wide range of applications with robust build. Here are the top reasons why air cylinders are an ideal actuator:

4.1 Cost-Effectiveness and Efficiency

Using motors to induce movements will require loads of electrical wire and power supplies. Similarly using hydraulics also requries oil supply which leads to a major initial cost and running cost. They are also heavy and challenging to manage. Air cylinders can also produce linear motion but only require a tube with pneumatic air for operation. These features make air cylinders:

• Low Maintenance

• Power Dense

• Energy Efficient

4.2 Safety and Reliability

Using pnematic air pipes to ensure clean operation. There is no fire hazard in compariosn to oil or high-power lelectrical conections. Air cylinders provide the following safety and reliability aspects:

• Clean Operation with Air

• Reduction in Fire Load

• Cushion for Smooth Stops

• Reliable 20M+ Cycles

4.3 Versatility and Customization

There are loads of types in air cylinders for engineers to choose. The versatility and customization is observable through:

• Wide Range of Sizes

• Variation in Material

• Mounting Systems

• Multi-Rod or Rodless Operations

• Adjustable Strokes

Example: Titan Automation's Customizable Stroke Adjustments

4.4 Environmental Advantages

Using fluids that can be harmful for the environment such as in hydraulics can lead to damage in reputation. In some cases it can lead to legal actions from the government. Air cylinders use pneumatic air which makes them ideal for clean industries such as medicine, hospitality,  food and beverage, and electronics manufacturing.

Conclusion

Air cylinders use compressed air for operations. It is a device that produces linear motion when compressed air is supplied to its ports. Engineers have developed different shapes, designs and working mechanisms of air cylinders to bring versatility in their applications. The key types are standard cylinders, compact cylinders, two & three rod cylinders, NFPA cylinders, all stainless steel cylinders, repairable round body cylinders, non-rotating with guide rods, and rodless cylinders. Their clean and safe operatoins makes them ideal for industrial automation, medical equipment, food processing, and heavy machinery applications.

If you are looking for a reliable supplier then explore all the options from Titan Automation. They offer tons of options to choose from while ensuring adherence to international standards including ISO, NFPA, VDMA. Their global compatibility and specialized designs showcase their manufacturing capability and expertise. Here are some of the types of air cylinders that Titan Automation produces:

• DNG: Double-acting Non-rotating Guide (Tie-Rod Standard Cylinder series, ISO 6431 compliant).

• NTA NFPA: NTA (Ningbo Titan Automation) NFPA Standard (North American Fluid Power Association compliant tie-rod cylinders).

• NTP: Non-rotating Tie-rod Pneumatic (Low-profile compact cylinder series, also known as pancake style).

• SDA: Square Double-Acting (Compact square-body cylinder series for space-saving applications).

• CXS: Compact eXtra Stable (Dual-rod non-rotating cylinder, interchangeable with SMC CXS).

• HN: High-stability Non-rotating (Mini free-mount twin-rod cylinder for alignment).

• ACK: Angle Clamp Kit (Pneumatic angle cylinder for 90°/180° rotations).

• NFPA TR: NFPA Tie-Rod (Standard NFPA tie-rod air cylinder for heavy-duty interchangeability).

• SSDA: Stainless Steel Double-Acting (All-stainless compact cylinder for corrosive environments).

• NTR: Non-rotating Tie-Rod Round (Repairable round-body cylinder with anodized aluminum).

• MAL: Mini Aluminium Linear (Nose-mount small pneumatic cylinder for linear motion).

• MGP: Multi-Guide Pneumatic (Compact guided actuator with dual guide rods for precision).

• NTA R: NTA Rodless (Rodless cylinder series for long-stroke, space-efficient motion).

FAQs

1. How Do I Size a Cylinder Correctly?

Analyze yoru requirements first. What stroke length do you need and what is the force requirement. Use the simple F=PxA formula to calculate the area requirement. Ensure that you have the stable pneumatic air pressure for the air cylinder for accurate measurements.

2. Can a Pneumatic Cylinder Stop Mid-Stroke?

Yes, modern magnetic piston designs allow cylinder to communicate its location in real-time with PLC or micro-processor. Using the direct feedback it can stop the air cylinder mid-stroke through the solenoid valve.

3. How Do I Know If My Air Cylinder Needs to Be Repaired or Replaced?

Reduction in force, loud hissing sound, visual scraches on the rod, broken seal, or clear signs of leakage indicate there is a need for repairing the air cylinder. However, you do need a repairable air cylinder type to perform repairs otherwise you can only replace.