Pulverizer Oil Lines Constantly Bursting? The 20411 Series Solves It with Zero Failures Per Year!

"It's leaking again!" In the control room of a thermal power plant's Phase III unit, the equipment technician frowned at the alarm light for the pulverizer's hydraulic system. This was the second time this year the unit had been shut down due to a burst oil line. Each repair was costly and led to lost power generation. The oil pipes in the pulverizer's hydraulic variable-load system act like "blood vessels," transporting hydraulic fluid. A burst or leak forces the entire system to shut down. This trouble was finally resolved—achieving "zero failures per year"—only after switching to the Dongfang SRI 20411-18-06Z/20491-18-06TZX6G2X750 oil pipe assembly.

I. A Faulty "Vascular System" in the Pulverizer Causes System "Illness"

The pulverizer hydraulic variable-load system is complex, featuring five or six operating modes, including initial state, self-circulation filtering, and variable-load operation. Each mode requires different fluid paths and pressures. The 20411-18-06Z/20491-18-06TZX6G2X750 oil line is the "critical artery" connecting core components like the oil pump, directional valve, and oil cooler.

• For example, during variable-load operation, it must stably deliver oil to the loading cylinder and return excess oil to the tank, with pressure accurately changing in sync with the coal feed rate.
• During roller lift, it must ensure orderly oil flow within the cylinder to prevent roller shaking or sticking.

This "arterial" role is challenging: the system's working pressure reaches 225 bar, and cleanliness requirements are extremely high; any impurity can block the oil circuit. Previously, using generic oil lines resulted in one of three failures: insufficient pressure resistance leading to bursts, poor sealing causing leaks, or corrosion within a few months. Technicians were constantly tied up with repairs.

II. Dongfang SRI Oil Lines: Three "Superpowers" That Solve Burst and Leak Issues

Dongfang SRI's solution relies on three "superpowers," each directly addressing a major pain point for power plants:

1. "Super-Strong" Pressure Resistance: Unaffected by Pressure Fluctuations

Generic oil lines cannot withstand 225 bar and will burst with slight fluctuations. This oil pipe, however, has a working pressure of 350 bar, offering a safety margin 56% greater than the actual requirement. Even if system pressure suddenly spikes, the line can handle it.

2. "Super-Reliable" Sealing: Not a Drop of Oil Leaks

Sealing failure is the most frustrating cause of leaks. This oil line is specifically designed with a 24-degree cone seal structure with an O-ring. Testing shows a leakage rate of less than 0.1 cubic centimeter per minute—meaning virtually no leakage over several years. Even under the 18 MPa of variable-load pressure, the seal remains stable and leak-free.

3. "Super-Durable" Resilience: Immune to Temperature Swings and Vibration

Pulverizer start-up and shutdown cycles involve massive temperature swings. Ambient winter temperatures can drop to -30 degrees C, while operating oil temperature reaches 60 degrees C. Generic lines might freeze and crack, or expand and leak. This Dongfang SRI line withstands temperature variations from -40 degrees C to 100 degrees C. Furthermore, the surface is carbon steel galvanized, creating a 5-10 micrometer passivation film, keeping contaminants within standards and extending lifespan significantly.

III. Dongfang SRI Oil Line Series Comparison: Selecting the Right Model for the Scenario

Dongfang SRI offers various oil line series tailored for different equipment needs, such as pulverizers and rolling mills. The comparison table below provides an overview:

A note on the High-Pressure Heavy-Load Series: Previously, rigid welded piping, prone to failure within 3 months under pulverizer vibration, was used. The Dongfang SRI flexible connection doubles the lifespan and directly reduces maintenance costs by 60%—saving a significant amount just on replacing oil lines.

IV. Real-World Cases

Actual performance is the best proof. Dongfang SRI oil pipes have been implemented in numerous power plants and steel mills, yielding remarkable results:

Case 1: Thermal Power Plant 1000 MW Unit Pulverizer Modification

A power plant with 2 x 1000 MW units running ZGM-123-II pulverizers frequently encountered hydraulic issues: fluctuating pressure and constant oil line leaks. A single repair cost over 50,000 RMB (approx. $7,000), causing significant distress to technicians.

After switching to the 20411-18-06Z / 20491-18-06TZX6G2X750 oil line assembly, three upgrades were implemented: double-layer steel wire braiding for a 1400 bar burst pressure; FKM (fluororubber) seals for temperature resistance from -40 to +120 degrees C; and precision crimping for a joint concentricity error of less than 0.1 mm, providing high vibration resistance. The results were immediate: the system failure rate dropped from 2.3 times per month to 0.1 times, and the oil line lifespan extended from 8 months to 24 months, saving a significant amount of maintenance costs annually!

Case 2: Steel Mill Rolling Mill Piping Upgrade

A steel mill's plate rolling mill frequently suffered interface failures in its hydraulic oil lines due to vibration, causing a 4-hour shutdown each time and a production loss of 500 tons of steel. They switched to the Dongfang SRI 45III-1000 crimped hose and quick connectors—the hose features a helical steel wire skeleton, improving vibration resistance by 40%. The quick connector's one-touch installation reduced replacement time from 2 hours to 15 minutes, drastically lowering labor costs. Following the modification, the rolling mill ran without a single failure for 18 consecutive months. The head of the equipment department stated: "Operating efficiency increased by 2.1%; we no longer have to rush in the middle of the night to repair a broken oil line!"

V. Selection Tips: How to Choose the Right Oil Line and Avoid Pitfalls

Here are a few selection suggestions for power plant and steel mill technicians to avoid choosing the wrong part:

• High-Pressure Main Oil Line (e.g., pulverizer main line): Ensure a safety margin of at least 30% above the working pressure to prevent bursting from pressure spikes; do not choose a line barely meeting the requirement.
• Precision Control Circuit (e.g., connected to proportional relief valves): Control accuracy should ideally be less than or equal to +/- 1% FS for precise and rapid response.
• Low-Temperature Environments (e.g., Northern power plants in winter): Choose the "MIN"-labeled Extreme Environment series to ensure the line remains flexible and doesn't become brittle at -40 degrees C.
• Routine Maintenance: For the 45III series oil lines, we recommend measuring the pressure every 6 months to ensure the crimped areas remain secure—safety first.

If you are unsure which model to choose or require detailed technical data, contact Dongfang SRI technical support directly. They can recommend the most suitable product based on your specific equipment conditions.

Ultimately, whether it's a pulverizer or a rolling mill, the oil line—though small—is a critical component that affects the entire system. Choosing a reliable product like the Dongfang SRI oil line reduces repairs and downtime and saves money—after all, stable operation is the greatest profit for a power plant!

HKCYT-2025-10-31