Internal vs. External Valve in Hydraulic Hammers: Key Differences and Their Impact

[MikePhua]

Hydraulic hammers are essential tools in heavy construction, demolition, and mining industries, used for breaking rocks, concrete, and other materials. One of the most critical components of hydraulic hammers is the valve system, which controls the flow of hydraulic fluid to the hammer. There are two primary types of valve systems used in hydraulic hammers: internal valves and external valves. In this article, we will explore the differences between these two types, how they function, and their advantages and disadvantages.
What is a Hydraulic Hammer?
A hydraulic hammer, also known as a hydraulic breaker, is a powerful attachment used with excavators, backhoes, and other heavy equipment. It is designed to deliver repeated, high-impact blows to break rock, concrete, asphalt, or other hard materials. The force generated by these hammers is typically controlled through hydraulic systems, which regulate the pressure and flow of hydraulic fluid to the piston inside the hammer.
Hydraulic hammers are widely used in construction, mining, and demolition work due to their efficiency and versatility. The main factors that influence the performance of a hydraulic hammer are the power of the hydraulic system, the design of the hammer itself, and the type of valve used to control the hydraulic flow.
Internal Valve System in Hydraulic Hammers
The internal valve system is built directly into the hydraulic hammer. It functions as an integral part of the hammer’s internal mechanism and controls the flow of hydraulic fluid to the piston. In this system, the valve is housed within the body of the hammer and is operated by the pressure from the hydraulic pump.
How It Works:

• The hydraulic fluid is directed through the internal valve and into the piston, causing it to move up and down.
  
• The valve controls the timing and intensity of the impact delivered by the hammer by regulating the flow of fluid.
  
• As the piston moves, the fluid pressure is adjusted by the internal valve to optimize the force and efficiency of the hammer's blows.
  

Advantages of Internal Valves:

1. Compact Design: The internal valve system is compact and integrated into the hydraulic hammer, making it more streamlined and simpler to maintain.
   
2. Reduced Risk of Leaks: Since the valve is housed inside the hammer, the chances of leaks are minimized.
   
3. Fewer Components: With fewer external components, the risk of parts being damaged or worn down is lower.
   
4. Better Control: The internal valve can provide more precise control of the hammer’s impact force and stroke timing.
   

Disadvantages of Internal Valves:

1. Limited Adjustability: The internal valve is typically fixed in terms of the settings it can control, meaning users may have limited ability to adjust performance characteristics, such as impact frequency or force.
   
2. Higher Repair Costs: If the internal valve fails, repairs may require disassembling the hammer, which can be more expensive and time-consuming compared to external valve systems.
   
3. Heat Accumulation: Internal valves can sometimes be prone to overheating, as the heat generated by the hydraulic system is not always efficiently dissipated.
   

External Valve System in Hydraulic Hammers
An external valve system, in contrast, is a separate component located outside of the hydraulic hammer. This system works alongside the hammer and is typically mounted directly on the machine or on the hammer itself, but it operates independently of the internal components. The external valve controls the flow of hydraulic fluid to the hammer and adjusts the pressure as needed to control the hammer's performance.
How It Works:

• The external valve is connected to the hydraulic lines of the machine and controls the flow of hydraulic fluid to the hammer.
  
• It is typically operated by an electronic or manual control system, allowing the operator to adjust the hammer's settings for different tasks.
  
• The external valve can be used to adjust the blow frequency, force, and other performance characteristics of the hammer.
  

Advantages of External Valves:

1. Adjustability: External valves offer more flexibility in adjusting performance settings, such as blow frequency, stroke length, and impact force, based on the task at hand.
   
2. Ease of Maintenance: If an external valve fails, it can often be repaired or replaced without having to disassemble the hammer itself, making maintenance easier and less costly.
   
3. Cooler Operation: Since the external valve is separate from the hammer’s internal components, it is less prone to heat buildup and may operate at cooler temperatures, leading to longer lifespan and less wear on parts.
   
4. Improved Performance in Specific Applications: External valves can be fine-tuned for specific applications, allowing for optimized performance in different materials or operating conditions.
   

Disadvantages of External Valves:

1. Increased Complexity: The external valve system introduces more components, which can increase the complexity of the overall hydraulic system.
   
2. Higher Risk of Leaks: With more external components, there is a higher risk of leaks or damage to hydraulic lines and connections.
   
3. Bulkier Design: The external valve system adds bulk and may require additional space, making the overall setup less compact than an internal valve system.
   

Key Differences Between Internal and External Valves

• Location: Internal valve systems are housed within the hydraulic hammer itself, while external valve systems are located outside the hammer.
  
• Adjustability: Internal valves typically offer limited adjustability, whereas external valves provide more flexibility for fine-tuning the hammer’s performance.
  
• Ease of Maintenance: Internal valves can be more complicated and expensive to repair, while external valves are generally easier to maintain and replace.
  
• Risk of Leaks: The internal valve has a lower risk of leaks, whereas the external valve system, with its additional components, may have a higher risk of leaks or damage.
  
• Heat Accumulation: Internal valves can accumulate heat, which can reduce efficiency, while external valves generally operate at cooler temperatures, improving performance.
  
• Cost of Repairs: Repairs to an internal valve system are typically more expensive due to the complexity of accessing and replacing internal components, whereas external valves are easier to repair.
  

Choosing Between Internal and External Valve Systems
The choice between an internal and external valve system largely depends on the specific requirements of the job, the operational environment, and the machine being used. Operators looking for a more compact and simple design may prefer internal valve systems, while those who need more control over performance and ease of maintenance might opt for external valve systems.
In heavy-duty applications, such as demolition or mining, where the hammer is subjected to constant heavy use, the flexibility of an external valve may offer a significant advantage. On the other hand, for smaller jobs or situations where space is tight, an internal valve may be more suitable.
Conclusion
Understanding the differences between internal and external valve systems in hydraulic hammers is essential for selecting the right equipment for your needs. Both systems have their own advantages and drawbacks, and the choice between them should be based on factors such as adjustability, maintenance ease, and performance requirements. Whether you are working on construction, mining, or demolition projects, selecting the appropriate valve system will help ensure that your hydraulic hammer performs efficiently and effectively over time.