learn about single acting and double acting cylinders, their differences, applications, pros, and cons. Discover the right choice for your hydraulic system needs.

Hydraulic Cylinders and Jacking Systems: Elevate Your Operations with LONGLOOD

LONGLOOD’s extensive range of hydraulic cylinders and jacking systems, setting the standard for excellence in manufacturing. As a major industry player in China, we directly provide our customers worldwide with cutting-edge jacking and lifting solutions at factory-direct prices, ensuring affordability without compromising on quality.

Direct manufacturer of Hydraulic Cylinders, competitive factory-direct prices.


Table of Contents

Different Types Of Hydraulic Cylinders LONGLOOD supplies

  • Single-Acting Hydraulic Cylinders

LONGLOOD offers single-acting hydraulic cylinders, which are the simplest type. These cylinders apply hydraulic force through a single port, typically for plunger extension. The return to the starting position is facilitated either by the load’s weight or by a built-in return spring.

LONGLOOD provides double-acting hydraulic cylinders, utilizing hydraulic flow for both advancing and retracting the plunger. Equipped with two connection ports, these cylinders require a compatible pump to provide hydraulic flow in both directions. The advantages include faster and more controlled retraction, making them suitable for applications requiring push and pull forces with repeatable accuracy.

  • Hydraulic Cylinders for Pulling Applications

LONGLOOD’s hydraulic cylinders for pulling applications are designed for tasks such as cable and bar tensioning. Typically single-acting with spring return.

LONGLOOD offers locknut cylinders, ideal for applications requiring extended load holding. This feature is available across different cylinder types, including low height, lightweight, or high-tonnage models.

  • LONGLOOD’s hollow plunger hydraulic cylinders

Also known as center-hole cylinders, deliver both pull and push forces. Featuring an internal thread for fixing to the item being pulled, they come in single-acting or double-acting variants, steel or aluminum builds, and may include removable saddles and steel base plates.

  • Telescopic Hydraulic Cylinders

LONGLOOD’s telescopic hydraulic cylinders provide extended stroke capabilities in confined spaces. The telescopic action allows lifting loads to a greater distance without temporary cribbing. When choosing a telescopic cylinder, users should consider the maximum load capacity, which decreases as it extends.

  • Lightweight Hydraulic Cylinders

LONGLOOD offers aluminum hydraulic cylinders suitable for various applications. Combining capacity and strength with lighter weight, aluminum cylinders are easier to transport and position. Resistant to corrosion, they are well-suited for caustic environments and are available in standard configurations with hardened steel saddles and base plates.

  • Tie-Rod Hydraulic Cylinders

LONGLOOD’s tie-rod cylinders are constructed with a head, base, and cylinder barrel connected by tie-rods. These offerings from LONGLOOD provide a comprehensive range to meet various operational requirements.

Why Use Hydraulic Locks

Hydraulic locks, also known as hydraulic locking mechanisms, are utilized in various applications for specific purposes. Here are some common reasons why hydraulic locks are used:

Load Holding:

Hydraulic locks are often employed to hold loads in a fixed position. By using a hydraulic locking mechanism, the system can maintain stability and prevent undesired movements or drift.

Safety and Security:

In applications where safety is a critical concern, hydraulic locks provide a secure means of preventing unintentional movement. This is especially important in situations where there may be human operators or workers in proximity to hydraulic equipment.
Positioning Accuracy:

Hydraulic locks are used to achieve precise positioning of components or systems. By locking certain elements hydraulically, it ensures accuracy in the placement and alignment of machinery or tools.

Energy Conservation:

Hydraulic locks can contribute to energy conservation in hydraulic systems. By locking a cylinder in a specific position, it eliminates the need to constantly supply hydraulic pressure to maintain that position, leading to energy savings.

Emergency Brake Systems:

Hydraulic locks are integrated into some emergency brake systems. In the event of a failure or emergency situation, the hydraulic lock can engage to halt movement and prevent further damage or injury.

Heavy Load Handling:

In applications where heavy loads need to be lifted or manipulated, hydraulic locks provide a means of securely holding the load in position without the constant need for hydraulic pressure.

Controlled Movement:

Hydraulic locks contribute to controlled and regulated movement in hydraulic systems. They ensure that movements occur precisely and are not affected by external forces.

Reduced Hydraulic System Leakage:

By using hydraulic locks, the need for constant hydraulic pressure to maintain a specific position is eliminated. This can reduce the risk of hydraulic system leakage and contribute to the overall efficiency of the system.

Preventing Drift:

Hydraulic locks are effective in preventing drift, which refers to the slow, unintended movement of hydraulic actuators due to internal leakage. The lock ensures that the actuator stays in the desired position without drifting.

Improved Stability in Heavy Equipment:

In heavy machinery such as cranes, excavators, or loaders, hydraulic locks contribute to stability during lifting or loading operations. They help prevent sudden movements or collapses that could be dangerous.

It’s important to note that the use of hydraulic locks depends on the specific requirements of the application. The decision to incorporate hydraulic locks into a system is based on factors such as safety regulations, precision requirements, load characteristics, and operational considerations.

How To Identify A Hydraulic Clinder ?

Identifying a hydraulic cylinder involves examining its physical characteristics, markings, and specifications.

Guides to help you identify a hydraulic cylinder:

Physical Examination

Size and Shape: Measure the physical dimensions of the cylinder, including the bore diameter, rod diameter, and overall length. This information helps determine the cylinder’s size.
Mounting Style: Note the mounting style, which can be clevis, flange, trunnion, or other configurations. This is crucial for understanding how the cylinder is attached to the equipment.

Cylinder Specifications

Operating Pressure: Identify the maximum operating pressure of the cylinder. This information is critical for ensuring that the replacement cylinder meets the system’s requirements.

Bore and Rod Diameter

Confirm the bore diameter (inner diameter of the cylinder) and rod diameter (outer diameter of the rod). These specifications impact the cylinder’s force and speed capabilities.

Stroke Length

Determine the stroke length, which is the maximum distance the rod can travel in and out of the cylinder.

Mounting Configuration

End Mounts: Examine the end mounts or attachment points of the cylinder. Note the type of mounts, such as clevis, flange, or trunnion mounts. This helps in identifying the cylinder’s application.

Rod End Features

Rod End Attachments: Check if the rod end has any attachments or features, such as eyes or clevises. This can indicate specific functions or applications.

Seal Type

Seals and Gaskets: Inspect the seals and gaskets on the cylinder. Different types of seals, such as rod seals and piston seals, serve specific purposes and can provide insights into the cylinder’s design.

Check for Wear or Damage

Wear Patterns: Look for wear patterns on the rod and cylinder body. Excessive wear or damage may indicate issues with the cylinder’s operation or maintenance.

11 Steps To Choose The Right Hydraulic Cylinder

Step1: Define Application Requirements:

Clearly understand the application’s requirements, including the load capacity, stroke length, operating environment, and speed of operation.
Determine Load and Force Requirements:

Calculate the force or load that the hydraulic cylinder needs to handle. Ensure that the selected cylinder has a sufficient load capacity for the application.

Step 2: Choose Cylinder Type:

Consider the type of hydraulic cylinder based on your application needs. Common types include single-acting, double-acting, telescopic, and as above mentioned types. Each type has specific advantages and limitations.

Step 3:Consider Operating Environment:

Evaluate the environmental conditions in which the hydraulic cylinder will operate. Factors such as temperature, humidity, and exposure to corrosive substances can impact the choice of materials and coatings.

Step 4:Determine Stroke Length:

Determine the required stroke length, which is the distance the hydraulic cylinder needs to move. Ensure that the selected cylinder provides the necessary stroke to meet the application’s requirements.

Step 5:Evaluate Speed Requirements:

Consider the speed at which the hydraulic cylinder needs to operate. Different applications may require varying speed capabilities, and the cylinder’s design should accommodate these requirements.

Step 6:Check Mounting Options:

Assess the available space and mounting options for the hydraulic cylinder. Choose a cylinder design that fits within the space constraints and offers appropriate mounting configurations.

Step 7: Select Cylinder Material:

Choose the cylinder material based on the specific environmental conditions and the type of load it will handle. Common materials include steel, stainless steel, and aluminum, each with its own set of advantages.

Step 8: Review Seal and Bearing Materials:

Pay attention to the seals and bearings used in the hydraulic cylinder. Ensure they are compatible with the hydraulic fluid and can withstand the operating conditions to prevent leaks and premature wear.

Step 9: Consider Cylinder Features:

Evaluate additional features such as cushioning for controlled deceleration, position feedback devices, and rod coatings for enhanced durability. Select features that enhance the overall performance and longevity of the hydraulic cylinder.

Step 10: Check Certification and Standards:

Verify that the hydraulic cylinder complies with industry standards and certifications. This ensures that it meets safety and performance requirements.

Seek guidance from LONGLOOD, we are leading high tonnage hydraulic cylinder manufacturers and suppliers. We can provide expertise, recommend suitable options based on your application, and assist with any specific customization needs.

Step 11: Budget Considerations:

Take into account budget constraints and compare different hydraulic cylinder options based on cost-effectiveness and long-term reliability.

By carefully considering these factors and consulting with our sales experts, you can select a suitable hydraulic cylinder that meets the specific needs of your application, ensuring optimal performance and longevity. If more questions please contact us.

Guides About How To Match A Hydraulic Cylinder With A Pump?

hydraulic pump and cylinder sets

Understanding the Basics

Hydraulic System Basics:

A hydraulic system consists of components like pumps, cylinders, valves, and hoses. The pump generates hydraulic pressure, which is transmitted through the fluid to actuate the cylinder.

Types of Hydraulic Pumps We Use:

Piston Pumps: More complex compared with gear pump, capable of higher pressures, and suitable for heavy-duty applications.

Determining Hydraulic Cylinder Requirements:

Define Application Requirements:

Understand the specific requirements of your application, including load capacity, speed, and stroke length.
Calculate Force and Pressure:

Calculate the force required to move the load using the hydraulic cylinder. Pressure is then determined by dividing force by the cylinder area.

Determine Cylinder Type:

Choose the appropriate type of hydraulic cylinder (single-acting, double-acting, etc.) based on your application needs.

Selecting the Right Pump:
We use piston pumps handle higher pressures. 

Consider Flow Requirements:

Determine the required flow rate of the hydraulic fluid, usually measured in gallons per minute (GPM). The pump’s flow rate should meet or exceed the system’s requirements.

Check Pressure Rating:

Ensure the pump’s pressure rating matches or exceeds the pressure required by the hydraulic cylinder. Consider safety factors and potential pressure spikes during operation.

Account for Efficiency:

Consider the efficiency of the pump. Efficiency affects the amount of input power needed to generate hydraulic pressure. Higher efficiency reduces energy consumption.

Evaluate Pump Size

Select a pump size that complements the cylinder’s size and speed requirements. The pump should be capable of delivering the necessary flow and pressure for efficient cylinder operation.

Ensuring Compatibility:

Check Pump and Cylinder Connection:

Ensure that the pump and hydraulic cylinder have compatible connection interfaces, including fittings, ports, and thread sizes.

Consider Fluid Compatibility:

Verify that the hydraulic fluid used is compatible with both the pump and the cylinder. Incompatible fluids can lead to seal degradation and system failure.

Seeking Professional from our Experts

We can provide valuable insights based on your specific application requirements.

Review System Dynamics:

Consider the overall system dynamics, including the interplay between the pump, cylinder, and other components. System inefficiencies can arise from mismatched components.

Testing and Adjustment

Perform System Tests:

Conduct tests with the selected pump and cylinder to ensure they work harmoniously. Monitor system performance and make adjustments if needed.

Regular Maintenance

Implement a regular maintenance schedule to ensure the longevity and efficiency of the hydraulic system.

Keep Records:
Maintain records of the pump and cylinder specifications, operating parameters, and any modifications made. This documentation is valuable for troubleshooting and future reference.


Matching a hydraulic cylinder with a pump involves a detailed understanding of the application, load requirements, and system dynamics. By following these steps and seeking professional advice from our sales experts, you can ensure a well-matched and efficient hydraulic system for your specific needs.Buy from China hydraulic cylinder manufacturer  like LONGLOOD could save you a lot of time.

What is a hollow hydraulic cylinder used for?

A hollow hydraulic cylinder, also known as a hollow plunger cylinder or center-hole cylinder, is a type of hydraulic cylinder that features a hollow center along the length of the piston rod. This design has specific applications where the hollow space is utilized for a particular purpose. Here are common uses for hollow hydraulic cylinders:

Tensioning Applications:

Hollow hydraulic cylinders are often used in applications where tensioning or pulling force is required. The hollow space allows for the passage of a rod or cable through the center, enabling the cylinder to apply force while accommodating the extended length of the material being tensioned.
Cable and Wire Tensioning:

In industries such as construction, bridge building, or cable-stayed structures, hollow hydraulic cylinders are employed to tension cables or wires. The cables can be threaded through the hollow center of the cylinder, and hydraulic pressure is applied to generate the required tension.
Pipe and Tube Bending:

Hollow hydraulic cylinders are used in pipe and tube bending machines. The hollow space allows the cylinder to engage with the pipe or tube while accommodating the material being bent. This is common in applications such as metal fabrication and construction.
Material Pulling and Holding:

Hollow cylinders are suitable for applications where materials need to be pulled or held in place. The central opening allows for the passage of materials through the cylinder, facilitating processes like pulling, holding, or clamping.
Rescue and Recovery Operations:

In emergency situations, hollow hydraulic cylinders can be used for rescue and recovery operations. For example, they might be employed to lift or pull heavy objects or structures in confined spaces, where the hollow space facilitates the use of cables or rods.
Hydraulic Tensioners:

Hollow hydraulic cylinders are commonly used in hydraulic tensioning systems, where precise and controlled tensioning of bolts or fasteners is required. The hollow design allows for the insertion of a tensioning tool through the cylinder, ensuring accurate and efficient tensioning.
Testing and Calibration:

Hollow cylinders can be used in testing and calibration applications where force or tension needs to be applied to various materials or components. The central opening accommodates the testing equipment or devices.
Hydraulic Jacks with Through-Hole Design:

Some hydraulic jacks, particularly those designed for specialized applications, feature a through-hole design. This allows for versatile use where materials, tools, or components can pass through the jack during operation.
The key advantage of hollow hydraulic cylinders is their versatility in accommodating additional materials or structures through the central opening, making them suitable for applications where tensioning, pulling, or passing through materials is necessary.

What is plunger in hydraulic cylinder?

In a hydraulic cylinder, the plunger is a critical component that moves back and forth within the cylinder to generate linear motion. The plunger is also commonly referred to as the piston or rod, and it is typically attached to a piston head or directly to the end of the piston. The terms “piston” and “plunger” are often used interchangeably in the context of hydraulic cylinders.

Here are the key features and functions of the plunger in a hydraulic cylinder:


The plunger is a cylindrical rod that extends from one end of the hydraulic cylinder. It is typically made of high-strength materials such as steel to withstand the forces and pressures involved in hydraulic applications.
Attachment to Piston:

In some hydraulic cylinders, the plunger is connected to a piston head, forming a single unit. The piston and plunger work together to displace hydraulic fluid within the cylinder and generate linear motion.

The plunger is equipped with seals, such as O-rings or other types of hydraulic seals, to prevent hydraulic fluid from leaking between the inside and outside of the cylinder. Proper sealing is crucial for the efficiency and reliability of the hydraulic system.
Linear Motion:

As hydraulic pressure is applied to one side of the piston, it generates a force that causes the plunger to move linearly within the cylinder. This linear motion is then used to perform various mechanical tasks, such as lifting, pushing, or pulling.
Single-Acting vs. Double-Acting Cylinders:

In single-acting hydraulic cylinders, hydraulic pressure is applied to one side of the piston, causing the plunger to extend. The return stroke is typically achieved by an external force (such as gravity or a spring). In double-acting cylinders, hydraulic pressure is applied to both sides of the piston, allowing the plunger to extend and retract based on the direction of hydraulic pressure.
End Attachments:

The end of the plunger may have various attachments or mounting features, depending on the specific application. These attachments may include eyes, clevises, or other connection points for linking the plunger to external components.
Guidance and Alignment:

The plunger is guided and aligned within the hydraulic cylinder to ensure smooth and precise movement. Bearings or other guiding mechanisms may be incorporated to minimize friction and wear.
Materials and Coatings:

Plungers are often made from materials with high tensile strength and may be coated or treated for enhanced durability and resistance to wear, corrosion, or other environmental factors.
Understanding the role and characteristics of the plunger in a hydraulic cylinder is essential for designing and selecting the appropriate hydraulic system for a given application. The plunger’s movement translates hydraulic pressure into mechanical work, allowing hydraulic cylinders to perform a wide range of tasks in various industries.

What is high tonnage hydraulic cylinder?

Key features and characteristics of high-tonnage hydraulic cylinders include:

High Load Capacity:

High-tonnage hydraulic cylinders are engineered to handle loads that exceed the capacity of standard hydraulic cylinders. They can generate substantial force, typically ranging from hundreds to thousands of tons.
Large Bore Sizes:

These cylinders often have larger bore sizes compared to standard cylinders. The larger bore allows for a greater volume of hydraulic fluid to act on the piston, resulting in higher force generation.
Robust Construction:

High-tonnage cylinders are constructed with heavy-duty materials to withstand the extreme forces and loads they are intended to handle. This includes the use of high-strength alloy steels and advanced manufacturing techniques.
High-Pressure Operation:

These cylinders are designed to operate at high hydraulic pressures to achieve the necessary force. The hydraulic system supplying the cylinder may include high-pressure pumps and components to meet the requirements of the application.
Special Sealing Systems:

Due to the high forces involved, high-tonnage hydraulic cylinders often incorporate specialized sealing systems to ensure effective sealing and prevent hydraulic fluid leakage. This includes robust seals and packing arrangements.
Versatile Mounting Options:

High-tonnage cylinders come with versatile mounting options to accommodate different installation requirements. This flexibility allows for integration into various heavy machinery and industrial equipment.
Extended Stroke Lengths:

These cylinders may be designed to offer extended stroke lengths, allowing for a wide range of motion in applications where significant travel is required.
Customization for Specific Applications:

High-tonnage hydraulic cylinders are often customized based on the specific needs of the application. This may include tailored dimensions, special rod coatings, or unique end attachments.

Common applications for high-tonnage hydraulic cylinders include heavy lifting equipment, metal forming presses, forging presses, mining equipment, shipyard machinery, and other heavy industrial processes.
Safety Considerations:

Due to the immense forces involved, safety is a critical consideration when working with high-tonnage hydraulic cylinders. Proper installation, maintenance, and adherence to safety standards are essential.
It’s important to note that the term “high-tonnage” is relative and may vary depending on the industry and application.

How to Select the Right Hydraulic Hose ?

Selecting the right hydraulic hose for your project is crucial to ensure optimal performance, safety, and longevity. Here are some key steps and considerations to help guide you in choosing the right hydraulic hose:

Understand System Requirements:

Know the pressure, temperature, and flow rate requirements of your hydraulic system. These factors will influence the type and specifications of the hose needed.
Determine Hose Size:

Choose the appropriate hose size based on the flow rate and velocity required for your application. The hose size must match the system’s demands to prevent inefficiencies or potential damage.
Consider Fluid Compatibility:

Ensure that the hydraulic hose is compatible with the type of hydraulic fluid used in your system. Different hoses are designed to withstand various types of hydraulic fluids, including oil, water, and synthetic fluids.
Check Temperature Range:

Verify the temperature range of the hydraulic system. Select a hydraulic hose that can withstand the temperature extremes of your operating environment. Consider both the fluid temperature and the ambient temperature.
Evaluate Hose Construction:

Hydraulic hoses come in different constructions, such as rubber, thermoplastic, or hybrid materials. Consider the specific requirements of your application and the conditions the hose will face, including abrasion, flexibility, and weight.
Determine Pressure Rating:

Understand the maximum working pressure of your hydraulic system. Select a hydraulic hose with a pressure rating that exceeds the maximum pressure in your system to provide a safety margin.
Assess Hose End Connections:

Choose hose end connections that are compatible with your system components. Common end connections include JIC, NPT, SAE, and others. Ensure a proper fit to prevent leaks and maintain system integrity.
Consider Bend Radius:

Evaluate the minimum bend radius of the hydraulic hose. This is crucial for applications with tight spaces or complex routing. Avoid exceeding the minimum bend radius to prevent hose damage.
Account for Hose Length:

Determine the required hose length based on the layout of your hydraulic system. Avoid excessive hose lengths, as they can lead to pressure drops and affect system performance.
Factor in Environmental Conditions:

Consider the environmental conditions the hydraulic hose will face, such as exposure to sunlight, chemicals, or abrasive materials. Choose a hose with the appropriate cover material to withstand these conditions.
Check Compliance and Certification:

Ensure that the hydraulic hose meets industry standards and certifications. Look for markings indicating compliance with specifications such as SAE, ISO, or DIN standards.
Consult with Suppliers:

How to Spot a Double-Acting Hydraulic Cylinder?

You can spot a double-acting cylinder by looking for the following characteristics:

Number of Ports:

A double-acting cylinder will have two connection ports—typically one on each end. This is in contrast to single-acting cylinders, which have only one port.
Rod End and Cap End:

Double-acting cylinders often have designations such as “rod end” and “cap end.” These refer to the two ends of the cylinder where hydraulic fluid is applied to extend or retract the piston.
Piston Rod:

Observe the piston rod. In a double-acting cylinder, the piston rod can extend and retract based on the application of hydraulic pressure to either end.
Application Context:

Consider the application context. Double-acting cylinders are commonly used in situations where bidirectional force and controlled movement are required, such as in material handling equipment, hydraulic presses, and manufacturing processes.
Hydraulic Pump Compatibility:

Double-acting cylinders require a compatible hydraulic pump that can provide hydraulic flow in both directions. The presence of a hydraulic pump with bidirectional capabilities is indicative of a double-acting system.
Control Valves and Lines:

In hydraulic systems with double-acting cylinders, you may find control valves and hydraulic lines that facilitate the controlled flow of hydraulic fluid to both sides of the cylinder.

Hydraulic cylinders used for pulling tasks

Hydraulic cylinders used for pulling tasks are specifically designed to exert force in the direction of retraction. These cylinders are often referred to as pulling cylinders or tension cylinders. Unlike typical hydraulic cylinders that are primarily designed for pushing or lifting applications, pulling cylinders are optimized for tasks that involve pulling loads or tensioning elements. Here are some key features and applications of hydraulic cylinders used for pulling tasks:

Single-Acting Configuration

Pulling cylinders are often single-acting, meaning hydraulic pressure is applied to extend the cylinder, and the retraction is achieved by an external force such as a spring or the load itself. This design is suitable for tasks where the pulling force is required in one direction.

Spring-Return Mechanism

Many pulling cylinders incorporate a spring-return mechanism to automatically retract the cylinder when hydraulic pressure is released. This simplifies the operation and allows for efficient use in repetitive tasks.

Cable and Wire Tensioning

Pulling cylinders are commonly used in applications where cables, wires, or other materials need to be tensioned. For example, in bridge construction or cable-stayed structures, hydraulic pulling cylinders can be employed to provide the necessary tension.
Anchor and Cable Tensioning in Construction:

In construction applications, pulling cylinders are utilized for tasks such as anchor tensioning or cable tensioning in post-tensioned concrete structures. The cylinder pulls and tensions the cables to enhance structural integrity.
Marine and Offshore Applications:

Pulling cylinders find use in marine and offshore applications for tasks like tensioning mooring lines, lifting and tensioning equipment on ships, or pulling heavy loads onto vessels.

Mining and Quarrying

In mining and quarrying operations, pulling cylinders may be employed for tensioning wire ropes or cables used in various machinery for lifting and transporting materials.

Tieback Tensioning in Geotechnical Engineering

Pulling cylinders play a role in geotechnical engineering, particularly in soil and rock stabilization. They are used for tieback tensioning systems to provide stability to structures like retaining walls.

Pulling and Aligning Components in Manufacturing:

In manufacturing processes, pulling cylinders can be used for tasks such as aligning and tensioning components during assembly. The controlled pulling force ensures precise positioning.

Pipeline Stringing in Oil and Gas Industry:

Pulling cylinders are used in pipeline stringing operations in the oil and gas industry. They help pull sections of pipeline into position and tension them during the installation process.

Emergency and Rescue Operations

In emergency situations, pulling cylinders may be employed for rescue and recovery operations. They can be used to pull apart debris or structures to access trapped individuals.
When selecting a hydraulic cylinder for pulling tasks, factors such as load capacity, stroke length, mounting options, and environmental conditions should be carefully considered. It’s essential to choose a pulling cylinder that meets the specific requirements of the task and ensures safe and efficient operation.

Features, Benefits And Typical Uses Of Locknut Hydraulic Cylinders

Locknut Hydraulic Cylinders

Load Holding for Extended Periods:

The primary characteristic of a locknut hydraulic cylinder is its capability for load holding over prolonged periods. This is especially advantageous in applications where a load needs to be securely held in a fixed position for an extended duration.
Available in Various Types:

Locknut feature is available across different types of hydraulic cylinders, including low height, lightweight, and high-tonnage models. This flexibility allows for the selection of a locknut cylinder based on the specific requirements of the application.
Load Security:

Locknut cylinders ensure the secure holding of a load without the need for continuous hydraulic pressure. This is particularly crucial in applications where safety and stability are paramount.
Energy Efficiency:

The locknut feature contributes to energy efficiency since it allows the hydraulic system to hold the load without continuous power input, reducing energy consumption.

The availability of the locknut feature in different cylinder types makes these cylinders versatile, suitable for various applications with diverse requirements.
Manufacturing and Assembly:

Locknut hydraulic cylinders are commonly used in manufacturing processes where parts or components need to be held securely in place during assembly or machining.
Heavy-Duty Industrial Processes:

In heavy-duty industrial processes, such as metalworking, forging, or pressing, locknut cylinders can secure heavy loads for extended periods.
Construction and Infrastructure:

Locknut cylinders find application in construction and infrastructure projects, where loads need to be securely held during tasks like lifting, positioning, or formwork.
Maintenance and Repair:

During maintenance and repair operations, locknut cylinders can be beneficial when holding components in a fixed position for inspection, welding, or other procedures.
Material Handling:

Locknut cylinders are used in material handling applications where loads, especially heavy or delicate ones, need to be securely held in a specific position.
Considerations for Locknut Hydraulic Cylinders:
Load Capacity:

Select a locknut hydraulic cylinder with an appropriate load capacity that matches the requirements of the application.
Locking Mechanism:

Understand the locking mechanism of the cylinder, whether it’s a mechanical locknut or another type of load-holding mechanism.
Cylinder Type:

Choose the right type of cylinder (low height, lightweight, high-tonnage, etc.) based on the specific needs of the application.
Environmental Conditions:

Consider the environmental conditions in which the cylinder will operate and select a cylinder with appropriate materials and surface treatments for durability.
Integration with Hydraulic System:

Ensure that the locknut hydraulic cylinder integrates seamlessly with the hydraulic system in terms of pressure, flow, and compatibility.
Safety Features:

Assess any additional safety features offered by the cylinder, such as pressure relief valves or load-holding valves, to ensure safe and reliable operation.

What is single hydraulic cylinder

A single hydraulic cylinder, also known as a single-acting hydraulic cylinder, is a type of hydraulic actuator that operates with hydraulic fluid pressure in one direction only. It is a relatively simple design and is commonly used in various industrial and mobile applications where unidirectional force is sufficient to perform the required task. Here are key features and characteristics of a single hydraulic cylinder:

Unidirectional Operation:

A single hydraulic cylinder operates in one direction only. Hydraulic pressure is applied to one side of the piston, causing it to move in one direction (either extending or retracting). The return stroke is typically achieved by an external force, such as a spring or the load itself.
Basic Components:

The basic components of a single hydraulic cylinder include a cylinder barrel, piston, rod (or plunger), seals, and ports for hydraulic fluid entry and exit. The hydraulic fluid is pressurized to extend the piston, and the return stroke is achieved by releasing the pressure.
Piston and Rod Design:

The piston is the component within the cylinder that separates the fluid on one side from the fluid on the other side. The rod, or plunger, is attached to the piston and extends through one end of the cylinder to provide the output force.
Spring Return Option:

Some single hydraulic cylinders feature a spring return mechanism. The spring assists in retracting the piston once hydraulic pressure is released. This design simplifies the hydraulic system and is often used in applications where the load itself is capable of providing the necessary return force.

Single hydraulic cylinders find applications in various industries, including construction, agriculture, material handling, and automotive. Common uses include lifting, pressing, clamping, and other tasks where unidirectional force is sufficient.
Cost-Effective Design:

Single hydraulic cylinders are often more cost-effective than their double-acting counterparts because of their simpler design and reduced complexity.
Gravity or External Force for Return Stroke:

In situations where a spring is not used, the return stroke may be accomplished by gravity (for vertically oriented cylinders) or by an external force that assists in retracting the piston.
Versatility in Mounting:

Single hydraulic cylinders come in various mounting configurations, including tie-rod, welded, and other styles, providing versatility in how they can be integrated into different systems.
Compact Size:

Single hydraulic cylinders are available in compact sizes, making them suitable for applications where space is limited.
Safety Considerations:

Operators should be cautious during the release of pressure, as the return stroke relies on external forces. Safety measures are essential to prevent unintended movement.
While single hydraulic cylinders are suitable for many applications, it’s important to carefully consider the specific requirements of a task. If bidirectional force is necessary, a double-acting hydraulic cylinder may be a more appropriate choice.

What is porta power kit ?

A porta power kit, short for portable power kit, is a versatile hydraulic tool set commonly used for heavy-duty applications such as automotive repair, body work, construction, and various other tasks that require controlled hydraulic force. The kit typically includes hydraulic cylinders, a hand pump, hoses, various attachments, and accessories. Porta power kits are known for their portability, ease of use, and the ability to provide hydraulic power in confined spaces.

Components of a Porta Power Kit:

Hydraulic Pump:

The hand pump is a manual hydraulic pump that pressurizes the hydraulic fluid to create the force needed to operate the hydraulic cylinders. It is typically operated by hand and provides a portable power source.

Hydraulic Cylinders:

Porta power kits include hydraulic cylinders of various sizes and configurations. These cylinders can be used for pushing, pulling, lifting, bending, or spreading applications. Common types include single-acting and double-acting cylinders.

Ram Attachments:

The kit may come with different attachments or rams that can be connected to the hydraulic cylinders. These attachments vary in design and function, allowing for a wide range of applications.


High-pressure hydraulic hoses are included to connect the hydraulic pump to the cylinders. The hoses are flexible and allow the operator to position the cylinders in various orientations.

Couplers and Fittings:

Couplers and fittings are provided to secure the connections between the hydraulic pump, hoses, and cylinders. They ensure a secure and leak-free hydraulic system.

Pressure Gauge:

Some porta power kits include a pressure gauge to measure the hydraulic pressure. This helps operators control and monitor the force applied during various tasks.

Carrying Case:

Many porta power kits come with a sturdy carrying case or box for convenient storage and transportation. The case helps keep the components organized and protected.
Common Applications of Porta Power Kits:

Automotive Repair:

Porta power kits are frequently used in automotive repair for tasks such as straightening frames, bending metal, or aligning components.

Body Work:

In the automotive and collision repair industry, porta power kits are employed for tasks such as pushing out dents, aligning panels, or straightening bodywork.


Porta power kits are useful in construction for tasks like lifting heavy objects, aligning structures, or providing controlled force in confined spaces.

Industrial Maintenance:

Maintenance and repair tasks in various industrial settings often involve the use of porta power kits for tasks such as lifting machinery, aligning equipment, or applying force where needed.

Rescue Operations:

Porta power kits can be utilized in emergency and rescue operations to lift or move heavy objects, create openings, or stabilize structures.

General Material Handling:

These kits are versatile tools for general material handling tasks, such as pushing, pulling, lifting, or bending various materials.

Considerations when Using Porta Power Kits:
Proper Training:

Operators should be properly trained on the use of porta power kits to ensure safe and effective operation.

Pressure Control:

Careful control of hydraulic pressure is essential to prevent damage to equipment or injury to personnel.

Correct Attachment Selection:

Using the appropriate attachments for the task at hand is crucial for achieving the desired results.

Safety Measures:

Follow safety guidelines and use appropriate personal protective equipment (PPE) when operating porta power kits.
Porta power kits are valuable tools in applications where hydraulic force needs to be applied in a controlled and portable manner. Their versatility and ease of use make them essential for a variety of tasks in different industries.

What is hydraulic hand pump? What is hydraulic electric pump? How to use them? And how to choose?

Hydraulic Hand Pump:

A hydraulic hand pump is a manually operated pump designed to generate hydraulic pressure by hand. It is commonly used in hydraulic systems where a portable and manually controlled power source is needed. Hydraulic hand pumps are often employed in applications such as hydraulic jacks, presses, and various other tools that require controlled hydraulic force.


How to Use a Hydraulic Hand Pump?


Position the Pump:

Place the hydraulic hand pump in a stable position, ensuring that it is securely anchored or attached to the hydraulic system.
Connect Hoses:

Attach hydraulic hoses to the pump’s inlet and outlet ports. Ensure proper connections to avoid leaks.
Prime the Pump (if necessary):

If the hydraulic system requires priming, follow the manufacturer’s instructions to fill the pump and hydraulic lines with fluid.
Operate the Pump Lever:

Pump the lever up and down. Each stroke of the lever pressurizes the hydraulic fluid, creating a flow of pressurized fluid to the connected hydraulic components.
Monitor Pressure and Fluid Flow:

Depending on the application, monitor pressure using a gauge (if available) and ensure that fluid is flowing as intended.
Cease Pumping:

Stop pumping once the desired pressure or fluid flow is achieved. Some hydraulic hand pumps may have a release valve to reduce pressure.
Secure Connections:

Carefully disconnect hoses, and secure all connections to prevent leaks.

Hydraulic Electric Pump:

A hydraulic electric pump is a pump powered by an electric motor to generate hydraulic pressure. These pumps are commonly used in applications where continuous and automated hydraulic power is required. Hydraulic electric pumps are versatile and find use in various industrial settings for tasks such as lifting, pressing, bending, and more.

How to Use a Hydraulic Electric Pump:

Power Connection:

Connect the hydraulic electric pump to a power source using the appropriate power cord or connection. Ensure that the power supply matches the pump’s requirements.
Connect Hoses:

Attach hydraulic hoses to the pump’s inlet and outlet ports. Ensure proper connections to avoid leaks.
Prime the Pump (if necessary):

Some hydraulic electric pumps may require priming to ensure that the pump and hydraulic lines are filled with fluid before operation.
Turn On the Pump:

Switch on the electric pump using the control panel, switch, or remote control, depending on the pump’s design.
Monitor Operation:

Monitor the pump’s operation, including pressure, flow rate, and any safety features. Many hydraulic electric pumps have built-in controls and indicators.
Cease Operation:

Turn off the electric pump once the desired pressure, flow rate, or task is completed.
Disconnect Power:

Disconnect the pump from the power source when finished. Follow proper safety procedures to avoid electrical hazards.


How to Choose Pump?


Consider the specific application for which you need the pump, whether it’s lifting, pressing, or other hydraulic tasks.
Flow Rate and Pressure:

Determine the required flow rate and pressure for your application. Different pumps are designed for varying levels of flow and pressure.
Power Source:

Choose between a hydraulic hand pump and a hydraulic electric pump based on the availability of a power source, the need for portability, and the frequency of use.
Fluid Compatibility:

Ensure that the pump is compatible with the type of hydraulic fluid you will be using.

Consider the operating environment. For example, if the pump needs to be submerged, a submersible electric pump may be suitable.

Evaluate the maintenance requirements of the pump. Some pumps may require more frequent maintenance, while others are designed for long-term reliability with minimal upkeep.

Compare the initial cost, operating costs, and maintenance costs of different pump options to choose a cost-effective solution.
Brand Reputation:

Consider the reputation of the pump manufacturer. Established and reputable brands often provide higher-quality and more reliable pumps.
User-Friendly Features:

Look for features such as easy controls, built-in safety features, and user-friendly designs that match your preferences and skill level.
Noise Level:

Consider the noise level produced by the pump, especially if it will be used in residential or noise-sensitive environments.
By carefully assessing your specific needs and considering the factors mentioned above, you can choose the right hydraulic pump—whether it’s a hand pump or an electric pump—for your intended application.

What is Hydraulic Pancake Cylinder?

A hydraulic pancake cylinder is a specific type of hydraulic actuator that features a flat, disk-like design. Like its pneumatic counterpart, the hydraulic pancake cylinder is characterized by its compact, low-profile shape, making it well-suited for applications where space is limited. These cylinders operate using hydraulic fluid (usually oil) to generate linear motion or force.

Key features of hydraulic pancake cylinders 

Flat Profile: The pancake cylinder has a flattened, disk-shaped profile, distinguishing it from traditional cylindrical hydraulic cylinders. This design allows for installation in tight spaces and applications with height restrictions.

Short Stroke Length: Typically, hydraulic pancake cylinders are designed for shorter stroke lengths compared to standard hydraulic cylinders. The stroke length refers to the distance the piston travels inside the cylinder.

Compact Size: The flat design contributes to a compact overall size, making hydraulic pancake cylinders suitable for installations in machinery or systems with limited space.

Hydraulic Operation: These cylinders use hydraulic fluid (such as oil) as the working medium. The hydraulic fluid is pressurized to create force or movement in the piston.

Applications: Hydraulic pancake cylinders find applications in various industries, including manufacturing, automation, and machinery. They are often used in scenarios where a shorter stroke length is sufficient, and a compact design is essential.

Force Output: While pancake cylinders are known for their space efficiency, their force output may be limited compared to larger hydraulic cylinders. The force output is determined by factors such as the cylinder size, pressure, and piston area.

Materials: Hydraulic pancake cylinders are typically constructed using materials suitable for hydraulic applications, ensuring durability and resistance to hydraulic fluid.

These cylinders are valued for their ability to provide hydraulic actuation in applications where traditional cylindrical cylinders may not be practical due to spatial constraints. The choice of a hydraulic pancake cylinder is influenced by factors such as available space, force requirements, and the specific needs of the application.

In summary, a hydraulic pancake cylinder is a hydraulic actuator with a flat, disk-like design, offering a compact solution for applications with limited space or those requiring a shorter stroke length.

Differences Between Aluminium Hydraulic Cylinder And Normal Hydraulic Cylinders:

Differences Between Hydraulic Cylinder And Normal Hydraulic Cylinders:


Aluminum Hydraulic Cylinder: Aluminum is a lightweight material, so aluminum hydraulic cylinders are generally lighter than their counterparts made of materials like steel.
Normal Hydraulic Cylinder: Cylinders made of steel or other materials may be heavier, especially in heavy-duty applications.
Corrosion Resistance:

Aluminum Hydraulic Cylinder: Aluminum has natural corrosion resistance, making aluminum cylinders suitable for applications where exposure to corrosive environments is a concern.
Normal Hydraulic Cylinder: Materials like steel may require additional coatings or treatments to enhance corrosion resistance.
Heat Dissipation:

Aluminum Hydraulic Cylinder: Aluminum has good thermal conductivity, allowing for effective heat dissipation. This feature can be advantageous in applications where heat buildup needs to be managed.
Normal Hydraulic Cylinder: The heat dissipation properties may vary depending on the material used.

Aluminum Hydraulic Cylinder: While aluminum is lightweight, it may not have the same strength as some other materials like steel. However, advancements in aluminum alloys have led to high-strength options.
Normal Hydraulic Cylinder: Materials like steel are known for their strength, making them suitable for heavy-duty applications.

Aluminum Hydraulic Cylinder: The cost of manufacturing aluminum hydraulic cylinders may be lower than that of some materials, making them cost-effective.
Normal Hydraulic Cylinder: The cost may vary based on the material used and the specific requirements of the application.
The choice between an aluminum hydraulic cylinder and a “normal” hydraulic cylinder (typically made of materials like steel) depends on the specific needs of the application. Aluminum cylinders are favored in applications where weight, corrosion resistance, and thermal conductivity are critical considerations.

What is hydraulic pull cylinder and how to operate?

A hydraulic pull cylinder, also known as a hydraulic puller or hydraulic pulling cylinder, is a specialized hydraulic tool designed for pulling or extracting components such as bearings, gears, bushings, or pulleys from shafts, hubs, or other parts. These cylinders use hydraulic force to apply a controlled pulling motion, making them useful in applications where components are tightly fitted or press-fitted and need to be removed without causing damage.

Key Features of Hydraulic Pull Cylinders:

Hydraulic Actuation: Hydraulic pull cylinders operate on the principle of hydraulic fluid pressure. When hydraulic pressure is applied to the cylinder, it generates a pulling force that can be used to extract or pull components.

Controlled Force Application: One of the primary advantages of hydraulic pull cylinders is their ability to apply a controlled and precise pulling force. This control helps prevent damage to both the component being pulled and the surrounding machinery.

Single-Acting or Double-Acting: Hydraulic pullers can be either single-acting or double-acting. Single-acting cylinders apply force in one direction and rely on an external force (e.g., spring or manual effort) for the return stroke. Double-acting cylinders use hydraulic pressure for both extension and retraction.

Versatility: Hydraulic pull cylinders come in various designs and sizes, allowing for versatility in different applications. They may be equipped with features such as adjustable jaws, extension rods, or modular configurations to suit specific needs.

How to Operate a Hydraulic Pull Cylinder:


Ensure that the hydraulic puller and associated equipment are in good condition.
Select the appropriate size and type of pulling attachments or jaws for the specific application.

Attach the hydraulic puller to the component to be removed, ensuring that the pulling jaws securely grip the part. The jaws may be adjustable to accommodate different sizes.

Position the hydraulic puller and components in a way that allows for a straight and controlled pulling motion.
Connect Hydraulic Hoses:

Connect hydraulic hoses from the hydraulic pump to the hydraulic puller. Ensure that the connections are secure.
Applying Hydraulic Pressure:

Start the hydraulic pump to apply pressure to the hydraulic puller cylinder. As hydraulic pressure increases, the cylinder exerts a pulling force on the attached component.
Monitoring and Adjusting:

Monitor the progress of the pulling operation. If needed, adjust the position or alignment of the hydraulic puller for optimal force application.
Component Extraction:

As the hydraulic puller applies force, the tightly fitted component should gradually begin to move or be completely extracted from the shaft, hub, or other parts.
Release Pressure:

Once the pulling operation is complete, release the hydraulic pressure and disconnect the hydraulic hoses.
Repeat or Move to Next Component:

If multiple components need to be removed, repeat the process for each one. Otherwise, disassemble the hydraulic puller for storage.
Safety Considerations:

Always follow the manufacturer’s guidelines and safety recommendations for the specific hydraulic puller being used.
Wear appropriate personal protective equipment, including safety glasses and gloves.
Ensure proper alignment and positioning to prevent damage to components or the hydraulic puller.
Use a hydraulic pump with the correct pressure capacity for the hydraulic puller.
By following these steps and adhering to safety guidelines, operators can efficiently and safely use hydraulic pull cylinders to remove press-fitted components in various industrial applications.

What is production hydraulic cylinder?

A production hydraulic cylinder, often referred to as an industrial hydraulic cylinder, is a type of hydraulic actuator designed for use in production and manufacturing processes. These cylinders play a crucial role in various industrial applications where controlled linear force is required to move, position, or manipulate components as part of a production line or manufacturing system.

Key Features of LONGLOOD Production Hydraulic Cylinders:

Heavy-Duty Construction: Production hydraulic cylinders are typically built with robust materials and construction to withstand the rigors of industrial production environments.

High-Cycle Performance: These cylinders are designed to endure frequent use, making them suitable for applications where high-cycle performance is essential, such as in continuous manufacturing processes.

Precision and Control: Production hydraulic cylinders provide precise control over linear movement, allowing for accurate positioning of components or tools in the manufacturing process.

Versatility: These cylinders are versatile and can be adapted to various manufacturing tasks, including lifting, pressing, clamping, pushing, or pulling, depending on the specific requirements of the production line.

Mounting Configurations: Production hydraulic cylinders are designed with different mounting configurations to facilitate easy integration into machinery and production systems. This can include collar threads, base threaded holes, plunger end threads, and various attachment options like foot mounts, flange mounts, retainer nuts, and clevis eyes.

Sealing and Lubrication: Special attention is given to sealing mechanisms to prevent hydraulic fluid leakage and ensure efficient operation. Lubrication is often incorporated to reduce friction and wear, contributing to the longevity of the cylinder.

Compatibility with Hydraulic Systems: These cylinders are compatible with hydraulic systems that include hydraulic pumps, valves, and hoses. The integration allows for centralized control and automation in production processes.


How to Operate a Production Hydraulic Cylinder?



Ensure that the hydraulic cylinder and associated equipment are in good condition.
Select the appropriate size and type of hydraulic cylinder for the specific application.

Mount the hydraulic cylinder securely in the desired position within the machinery or production system.
Connect Hydraulic Hoses:

Connect hydraulic hoses from the hydraulic pump to the hydraulic cylinder. Ensure that the connections are secure.

Position the production hydraulic cylinder and components in a way that allows for a straight and controlled linear motion.
Applying Hydraulic Pressure:

Start the hydraulic pump to apply pressure to the hydraulic cylinder. As hydraulic pressure increases, the cylinder extends or retracts, depending on its design and application.
Monitoring and Adjusting:

Monitor the movement of the hydraulic cylinder and the components it is interacting with. If needed, adjust the pressure or position for optimal performance.
Component Manipulation:

Use the hydraulic cylinder to manipulate or position components according to the requirements of the production process. This can include lifting, pressing, clamping, pushing, or pulling tasks.
Release Pressure:

Once the desired operation is complete, release the hydraulic pressure and disconnect the hydraulic hoses.
Repeat or Move to Next Operation:

If multiple operations are required, repeat the process for each one. Otherwise, prepare the hydraulic cylinder for the next production task.
Safety Considerations:

Always follow the LONGLOOD’S  guidelines and safety recommendations for the specific production hydraulic cylinder being used.
Wear appropriate personal protective equipment, including safety glasses and gloves.
Ensure proper alignment and positioning to prevent damage to components or the hydraulic cylinder.

Use a hydraulic pump with the correct pressure capacity for the hydraulic cylinder.
By following these steps and adhering to safety guidelines, operators can efficiently and safely use production hydraulic cylinders to perform various tasks in industrial production and manufacturing settings.

What Is Single-Acting Hollow Plunger Hydraulic Cylinder?

A Single-Acting Hollow Plunger Hydraulic Cylinder is a type of hydraulic actuator designed for specific applications where the cylinder needs to both push and pull loads, and there is a need for a hollow plunger. This type of hydraulic cylinder is classified as “single-acting” because hydraulic pressure is applied only in one direction, typically for extending the plunger. The return stroke, or retraction of the plunger, is achieved by an external force such as a spring or the load itself.

Here are some key features of LONGLOOD Single-Acting Hollow Plunger Hydraulic Cylinder:


Hollow Plunger Design:

The plunger, or rod, of the hydraulic cylinder has a hollow interior. This design allows the cylinder to be used for applications where the cylinder needs to both push and pull, and where the hollow space can accommodate a rod or cable to perform pulling tasks.

Hydraulic Force Application:

Hydraulic pressure is applied to one side of the piston, causing the plunger to extend. This hydraulic force is used to push against or lift a load.

Spring or Load Return:

The retraction of the plunger (return stroke) is typically achieved by an external force, such as a spring integrated into the cylinder or the weight of the load itself. This design simplifies the hydraulic system and reduces the need for additional hydraulic components.

Single-Acting Operation:

As mentioned, the hydraulic pressure is applied only in one direction, making it a single-acting cylinder. The other direction of movement relies on an external force.


Pulling Tasks: The hollow plunger design is particularly useful for applications where pulling tasks are required, such as cable or bar tensioning, extracting bearings, or any task where a rod or cable needs to pass through the plunger.

Limited Space: The hollow plunger design is beneficial in situations where space is limited, and a telescopic or other design may not be suitable.

Versatile Applications: Suitable for various industrial applications where a combination of pushing and pulling forces is needed.

What Is Double-Acting Hollow Hydraulic Cylinder?

A Double-Acting Hollow Hydraulic Cylinder is a type of hydraulic actuator designed for applications where hydraulic force is required in both the extending and retracting strokes, and it features a hollow plunger. This type of hydraulic cylinder is considered “double-acting” because hydraulic pressure can be applied on both sides of the piston, allowing for controlled movement in both directions.

Here are the key features of LONGLOOD Double-Acting Hollow Hydraulic Cylinder:

Hollow Plunger Design: Similar to the single-acting version, the double-acting hollow hydraulic cylinder has a hollow plunger or rod. This design allows for versatility in applications where both pushing and pulling forces are required, and a rod or cable can pass through the hollow interior.

Hydraulic Force in Both Directions: Hydraulic pressure can be applied to either side of the piston, enabling force to be generated in both the extending and retracting strokes. This allows for controlled and precise movements in both directions.

Dual Hydraulic Ports: Double-acting cylinders typically have two hydraulic ports, allowing hydraulic fluid to be directed into either end of the cylinder depending on the desired direction of motion.

Versatility in Applications:

Push and Pull Tasks: Well-suited for applications that require both pushing and pulling forces, such as lifting and lowering loads, pushing or pulling objects, or tensioning cables.

Increased Control: The ability to apply hydraulic force in both directions provides more control over the movement of the cylinder, making it suitable for tasks that require precision.

Reduced External Forces: Unlike single-acting cylinders that rely on external forces (e.g., springs or loads) for retraction, double-acting cylinders can use hydraulic pressure for controlled retraction.

Applications in Limited Space: Like the single-acting version, the hollow plunger design can be beneficial in applications where space is limited, and a telescopic or other design may not be suitable.