Original priority valve VLE-150S, part number HZ1431-76-05000D-01, is suitable for loader SL56H and SL53H.

Original Priority Valve VLE-150S, Part No. HZ1431-76-05000D-01, suitable for SL56H and SL53H loaders.

The priority valve is a crucial control element. "Original priority valve" typically refers to the traditional, basic type of priority valve, as opposed to more advanced modern load-sensitive systems (such as load-sensitive priority valves).

Core Functions and Purpose

Ensuring Critical Functional Oil Supply: Its core task is to prioritize ensuring sufficient and continuous hydraulic oil flow and pressure to the steering system, regardless of engine speed or the movement of the working devices (such as the bucket and boom). Steering system failure means loss of equipment control and extremely high safety risks.

Remaining Flow Distribution: After meeting the steering system's needs, the remaining hydraulic oil flow is then distributed to other working devices (working hydraulic systems), such as bucket lifting, tipping, and auxiliary hydraulics.

Safety First: This is a safety principle in the design, ensuring that the operator can control the equipment's direction under any working conditions.

The "original priority valve" is a classic flow distribution control valve in hydraulic systems of construction machinery, still widely used (especially in older or budget-friendly equipment). Its core objectives are simple structure, low cost, and reliable steering priority. However, its design, based on a fixed displacement pump and an open-type valve, results in drawbacks such as high energy consumption, low efficiency, significant heat generation, and poor coordination of complex movements. With technological advancements, more efficient and intelligent load-sensitive systems are gradually becoming the mainstream choice for mid-to-high-end equipment, but understanding the working principle of the original priority valve remains fundamental for diagnosing and maintaining a large number of in-use equipment.