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As a leading manufacturer of high-performance Hydraulic Valves, Longerfa Hydraulic specializes in durable and precision-engineered components for construction, agriculture, and industrial machinery. The DH55/DH60 rotary valves are widely used in Hydraulic Systems due to their reliability and efficiency. However, like all mechanical components, they require periodic maintenance to prevent leaks and ensure smooth operation.

This comprehensive technical guide provides step-by-step instructions for disassembly, seal replacement, and reassembly of DH55/DH60 rotary valves, helping maintenance professionals extend service life and reduce downtime.

Longerfa Hydraulic's DH220-5 Universal Swing Valve is engineered to deliver smooth, shock-free rotation control in diverse hydraulic applications. But which machines is it truly compatible with? Our latest rigorous compatibility tests provide the answers.

This valve's compact design, adjustable cushioning, and robust construction make it suitable for integration into various hydraulic systems, from construction equipment to industrial machinery. Below, we break down the key findings from our testing.

The DH220-5 Cushion Swing Valve, developed by Longerfa Hydraulic, is a high-performance hydraulic control component widely used in construction machinery, metallurgical equipment, and automated production lines. Its primary function is to smoothly control the rotary motion of hydraulic actuators while minimizing shock and vibration.

This valve features a pilot-operated cushioning adjustment mechanism, which precisely regulates the rotation speed of hydraulic motors or cylinders by adjusting spool opening and throttling resistance. When sudden pressure changes occur in the system, the DH220-5 automatically modulates flow to prevent damage caused by hydraulic shock, thereby extending equipment lifespan and improving operational stability.

Hydraulic control valves are critical components in heavy machinery like Caterpillar (CAT) excavators, ensuring precise movement and optimal performance. When these valves fail, operators face a crucial decision: should they choose expensive OEM (Original Equipment Manufacturer) replacements or more affordable high-compatibility alternatives?

At Longerfa Hydraulic, we specialize in manufacturing high-performance, cost-effective hydraulic valves that meet or exceed OEM standards. In this article, we compare CAT OEM valves with Chinese high-compatibility valves in terms of cost, durability, and performance—helping you make an informed decision for your machinery.

CAT excavators are renowned for their durability and performance in heavy-duty construction and mining operations. However, like all hydraulic machinery, their control valves (commonly referred to as "proportional valves" or "main control valves") can develop faults over time. Understanding and diagnosing these faults is crucial for minimizing downtime and ensuring optimal performance.

At Longerfa Hydraulic, a leading manufacturer of high-quality hydraulic components, we specialize in providing reliable solutions for excavator valve systems. In this article, we will explore the most common fault codes related to CAT excavator control valves, their causes, and recommended troubleshooting steps.

The Caterpillar CAT312 excavator relies on precise hydraulic valve performance for efficient operation, especially in demanding applications like demolition, rock breaking, and trenching. The Main Relief Valve 222-0084 and secondary hammer valve must work in perfect harmony to ensure optimal hydraulic pressure, flow control, and energy efficiency.

However, improper hydraulic matching between these valves can lead to:
✔ Reduced hammer impact force
✔ Overheating and premature wear
✔ Unstable hydraulic pressure fluctuations
✔ Increased fuel consumption

In this technical guide, Longerfa Hydraulic—a trusted manufacturer of high-performance hydraulic valves—explains how to optimize the CAT312 main and secondary hammer valve system for maximum efficiency and durability.

The CAT320C secondary hammer valve is a critical component in hydraulic systems, especially for excavators engaged in high-frequency demolition, rock breaking, and heavy-duty digging. However, internal leakage is a common issue that can lead to reduced hydraulic efficiency, overheating, and increased fuel consumption.

In this technical guide, we’ll explore:
✔ Why internal leakage occurs in CAT320C secondary hammer valves
✔ Step-by-step disassembly and inspection process
✔ Key components prone to wear and failure
✔ Proven solutions to prevent leakage and extend valve life

Whether you're a hydraulic engineer, equipment owner, or repair technician, this article provides actionable insights to optimize your CAT320C’s performance.

Hydraulic systems in excavators and industrial machinery rely on precision components like excavator relief valves, self-reducing valves, and auxiliary control valves to function efficiently. One of the most common issues affecting these valves is spool sticking, which can lead to operational delays, pressure loss, and even system failure.

At Ningbo Longerfa Hydraulic Co., Ltd., we understand the urgency of resolving spool sticking to minimize downtime. This guide provides emergency troubleshooting steps to restore valve functionality quickly while ensuring long-term reliability.

Hydraulic systems are the backbone of heavy machinery, including excavators, construction equipment, and industrial applications. However, one of the most common causes of hydraulic component failure is oil contamination, which can severely impact critical valves such as excavator relief valves, self-reducing valves, and auxiliary control valves. At Ningbo Longerfa Hydraulic Co., Ltd., we emphasize proactive measures to prevent contamination and ensure optimal performance.

Ningbo Longerfa Hydraulic Co., Ltd – Replacing cartridge valves in hydraulic excavators is a critical maintenance task that ensures smooth operation and prevents system failures. However, improper bleeding after installation can lead to air pockets, erratic pressure control, and even damage to key components like the hydraulic excavator overflow valve or hydraulic excavator pressure relief valve.

As a leading manufacturer of hydraulic excavator relief valves, Longerfa provides expert guidance on proper system Venting techniques to maintain reliable and durable excavator overflow valve performance.