Views: 0 Author: Kun Tang Publish Time: 2026-01-16 Origin: Jinan YZH Machinery Equipment Co., Ltd.
In hydraulic engineering, "close enough" is never good enough. The relationship between the power source (like an Excavator or a Hydraulic Power Unit) and the attachment (like a rock breaker) is defined by precise mathematics.
When the Flow Rate (LPM) or Operating Pressure (Bar) is mismatched, the consequences go far beyond just "slow performance." It creates a domino effect of thermal failure, mechanical stress, and safety hazards that can destroy expensive machinery in a matter of hours.
This guide details the six specific problems caused by hydraulic incompatibility and how to avoid them.
The most immediate sign of a mismatch is a drop in performance.
Low Flow (LPM): If your power unit supplies less oil than the breaker requires, the frequency (blows per minute) drops. The tool will strike slowly, failing to build the resonant frequency needed to fracture hard rock.
Low Pressure: If the system pressure is below specification, the impact energy (Joules) of each blow is reduced. The breaker will simply "bounce" on the rock without penetrating.
The Fix: Ensure your Hydraulic Power Unit is calibrated to deliver the exact flow curve required by the attachment.
This is the most expensive consequence. Hydraulic systems operate on a delicate thermal balance.
The Physics of Excess Flow: If the power source pumps 200 LPM into a breaker designed for 150 LPM, that extra 50 liters has nowhere to go. It is forced through the relief valve at high pressure.
The Result: This process converts hydraulic energy directly into Heat.
The Damage: Overheated oil destroys rubber seals (causing leaks), glazes cylinder walls, and seizes internal pistons. A mismatch here can ruin a brand-new breaker in a single shift.
Mismatched systems are unpredictable systems.
Pressure Spikes: If the hydraulic pressure exceeds the rating of the hoses or the attachment, you risk a hydraulic burst. High-pressure oil injection injuries are severe and life-threatening.
Loss of Control: Inconsistent pressure can cause erratic movements. If an attachment engages suddenly or fails to stop when the valve is closed, it poses a direct danger to ground personnel.
Weight Imbalance: While not hydraulic, physical mismatching (putting a heavy tool on a light carrier) leads to tipping hazards.
A mismatched system is a stressed system.
Seal Failure: High pressure blows out seals. High temperature hardens them. Both lead to constant replacement.
Pump Wear: If a hydraulic pump is constantly fighting against back-pressure from a restrictive attachment, the pump's lifespan is cut in half.
The Bottom Line: You might save money renting a generic power pack, but you will spend double that amount repairing your equipment. Investing in a dedicated, adjustable Hydraulic Power Unit is cheaper in the long run.
Time is the most valuable resource on a construction site.
Downtime: Every hour spent letting an overheated system cool down is an hour of lost production.
Slow Progress: A breaker operating at 60% efficiency due to low flow means the job takes 40% longer to complete. This extends project timelines and increases labor costs.
Oil is the lifeblood of the system, and mismatching poisons it.
Viscosity Breakdown: As mentioned in point #2, excess flow creates heat. When oil gets too hot (usually above 80°C/176°F), its viscosity breaks down. It becomes thin like water, losing its ability to lubricate metal parts.
Metal Shavings: Thin oil leads to metal-on-metal contact between the piston and cylinder. This generates metal filings (contamination) that circulate through the system, destroying pumps and valves throughout the entire machine.
The risks of hydraulic mismatch—overheating, safety hazards, and massive repair bills—are entirely preventable.
The most effective solution, especially for stationary boom systems or specialized attachments, is to use a dedicated Hydraulic Power Unit (HPU). Unlike a shared excavator line, an HPU can be precisely set to the exact Flow (LPM) and Pressure (Bar) required by your tool, ensuring 100% efficiency and zero thermal waste.
Don't risk your equipment.Check our range of electric and diesel Hydraulic Power Units designed for perfect compatibility and continuous duty.
Q1: What happens if the hydraulic pressure is too high for the breaker?
A: Excessive pressure causes the piston to strike with too much force, which can snap the tie rods (the long bolts holding the breaker together) or crack the tool itself. It also puts the hoses at risk of bursting.
Q2: Can I use a flow control valve to fix a mismatch?
A: Yes, but it generates heat. A flow control valve restricts flow, and that restriction creates friction/heat. It is a temporary fix. The better solution is a variable displacement pump on a dedicated Hydraulic Power Unit that only generates the flow you need.
Q3: How do I know the correct flow for my attachment?
A: Always check the "Specifications" plate on the attachment. It will list a range (e.g., 120-150 LPM). Your power source must be set within this range, ideally in the middle.
Q4: Why is my hydraulic oil turning dark/black?
A: Dark oil usually indicates thermal degradation (burning) or contamination. This is a classic sign of a mismatched system running too hot. You need to change the oil and check your flow settings immediately.
