Effective Methods for Splitting Auxiliary Hydraulic Circuits in Heavy Equipment

[MikePhua]

Auxiliary hydraulic systems provide the versatility needed to operate various attachments on heavy equipment such as backhoes, loaders, and excavators. Often, operators or technicians face the challenge of splitting one auxiliary hydraulic line into two or more to power multiple attachments or perform complex tasks. This article explores practical methods to split auxiliary hydraulics, explains key terminology, and shares real-world insights and examples.
Understanding Auxiliary Hydraulic Systems
Auxiliary hydraulics refer to the additional hydraulic circuits on equipment designed to power attachments beyond the primary functions. These systems usually consist of:

• Hydraulic Pump: Generates flow and pressure.
  
• Control Valves: Direct fluid to attachments.
  
• Hydraulic Lines and Hoses: Carry pressurized fluid to and from attachments.
  
• Quick Couplers: Allow easy connection/disconnection of hydraulic hoses.
  

Splitting an auxiliary hydraulic circuit involves dividing the hydraulic flow so multiple attachments or functions can be controlled independently or simultaneously.
Common Reasons to Split Auxiliary Hydraulics

• Operating two hydraulic tools from one auxiliary circuit.
  
• Adding extra hydraulic functions to an attachment.
  
• Increasing productivity by running dual attachments.
  
• Testing or troubleshooting hydraulic components without reconfiguring existing plumbing.
  

Methods to Split Auxiliary Hydraulic Lines

1. Using Hydraulic Tee Fittings
   The simplest method, hydraulic tees allow a single hydraulic line to be split into two branches. However, this method divides the available flow between both lines, which may reduce the performance of each attachment.
   
2. Using a Hydraulic Flow Divider/Combiner
   Flow dividers evenly distribute hydraulic flow to multiple outputs. Some dividers allow combining flows from multiple inputs back to one line, useful for synchronized operations or power sharing.
   
3. Installing a Secondary Control Valve
   Adding a dedicated control valve for the split line permits independent control of each branch. This setup requires additional plumbing but offers the greatest control and safety.
   
4. Using Multi-Function Auxiliary Control Systems
   Modern equipment may have built-in multi-function auxiliary systems that allow control over several hydraulic outputs from the cab, often adjustable via electronic controls.
   
5. Utilizing Hydraulic Manifolds
   Hydraulic manifolds can centralize the splitting of flow and pressure, provide pressure relief, and incorporate multiple control valves in a compact unit.
   

Considerations When Splitting Auxiliary Hydraulics

• Flow Rate and Pressure Limitations
  Splitting flow reduces the available hydraulic power to each function unless the pump capacity is sufficient.
  
• Compatibility of Attachments
  Attachments may require different flow or pressure settings; ensure the system can meet those requirements.
  
• Potential for Overheating
  Excessive flow through split lines without proper management can cause fluid heating and component wear.
  
• Safety Concerns
  Incorrect splitting can lead to uncontrolled movements or pressure spikes. Use pressure relief valves and test systems carefully.
  

Real-World Examples

• A landscaping contractor equipped a skid steer with both a hydraulic auger and a grapple by splitting the auxiliary line with a flow divider and adding a secondary valve. This setup allowed them to switch between tools without changing hoses constantly.
  
• A farmer modified their backhoe’s auxiliary circuit using tee fittings to run a hydraulic breaker and a thumb attachment, improving efficiency in demolition and material handling.
  
• In a heavy construction project, an operator used a hydraulic manifold to split and control multiple auxiliary outputs for simultaneous operation of a hydraulic hammer and a clamshell bucket, increasing work speed.
  

Terminology Glossary

• Auxiliary Hydraulic: Additional hydraulic circuits used to power attachments.
  
• Flow Divider: A device that splits hydraulic flow evenly between two or more outputs.
  
• Hydraulic Tee: A plumbing fitting shaped like a "T" used to split or combine hydraulic lines.
  
• Control Valve: A valve that regulates the flow and direction of hydraulic fluid.
  
• Manifold: A block containing multiple hydraulic passages and valves to manage flow.
  
• Quick Coupler: A connector that allows quick connection and disconnection of hydraulic hoses.
  
• Pressure Relief Valve: A safety valve to prevent excessive pressure buildup.
  

Industry Insights
Splitting auxiliary hydraulics is a common modification that can greatly enhance the flexibility and productivity of construction and agricultural equipment. While simple solutions like tee fittings are easy to implement, they may not always be the best choice for demanding applications. Flow dividers and secondary control valves provide better performance and safety but require more complex installation and understanding of hydraulics.
Advancements in electronic controls have also made multi-function auxiliary systems more user-friendly, allowing operators to manage multiple attachments with greater precision.
Conclusion
Splitting auxiliary hydraulic circuits requires careful planning and understanding of hydraulic principles. Whether using simple tees, flow dividers, secondary valves, or manifolds, the goal is to maintain safe and efficient operation without compromising hydraulic power.
Operators and technicians should evaluate their specific needs, flow requirements, and control preferences before modifying auxiliary hydraulic systems. With proper design and components, splitting auxiliary hydraulics can unlock new capabilities and improve operational efficiency on the jobsite.