Description
4P9827 Special piston assembly for single pump of large construction machinery and mining equipment, a core precision component for establishing high-pressure fuel in the single-pump injection system. The overall quenched and tempered alloy steel piston, with a thickened and resistant-to-high-temperature-high-pressure reset spring, is assembled with a black oil-resistant sealing ring in the middle section. The top is equipped with a transparent dust-proof protective cap, and the outer wall is engraved with part identification codes. The factory completes a complete set of bench tests for piston clearance, high-pressure sealingity, and elastic consistency, solving faults such as uneven fuel supply in each cylinder, idle vibration, insufficient power under heavy load, difficulty in cold start, fuel pressure leakage inside the oil pump, and difficulty in secondary startup after engine shutdown due to oil dilution by diesel. The piston and spring are precisely ground and matched in pairs at the factory, allowing for direct replacement and repair. Product Overview
The single piston relies on the cam to reciprocally compress the fuel, providing stable high-pressure fuel for the injector and controlling the fuel injection volume and pressure for each cylinder. Under long-term mining conditions of 24 hours of continuous heavy load, ultra-high fuel pressure reciprocating impact, and exposure to poor-quality diesel, the wear gap of the piston and pump body mating surface increases, the sealing ring ages and fails, resulting in a large amount of high-pressure fuel leakage, difficulty in establishing fuel pressure, significant reduction in equipment power, thick black smoke from exhaust, difficulty in starting after shutdown, fuel pump internal fuel pressure relief, and difficulty in secondary startup after oil dilution by diesel. This product's piston, spring, and sealing components are processed as a complete set, with standardized dimensions, stroke, and spring elasticity. Maintenance does not require on-site grinding processing, and it is suitable for maintenance of single pumps for large mining excavators, heavy-duty loaders, and high-power diesel generators.
Core advantages of the single unit
Micro-micron mirror surface ultra-precision grinding piston, with extremely low internal leakage of high-pressure fuel supply stability
The outer circle of the piston and the mating surface of the pump body are mirror-quenched and ground, with strict calibration of the mating gap, resulting in a small amount of fuel backflow leakage under high-pressure conditions, uniform fuel supply volume for each cylinder, smooth engine operation, and reduced black smoke and fuel loss.
Thickened and resistant-to-high-temperature alloy reset spring, with durable and不易fatigue elasticity
The large-diameter high-pressure spring undergoes high-temperature tempering treatment， with unified elasticity calibration， and is not prone to fatigue deformation under long-term high-frequency reciprocating compression， ensuring the piston returns to position completely and eliminating incomplete fuel injection and speed drift problems.
Integrated black oil-resistant sealing ring， long-term sealing against fuel leakage
The middle section is equipped with a fluorine rubber sealing ring， resistant to diesel swelling and high/low temperatures， closely adhering to the outer wall of the piston， and effectively blocking the downward leakage of high-pressure fuel through the piston gap， preventing diesel from mixing with lubricating oil and diluting the engine oil.
The outer wall of the piston is engraved with clear part codes， facilitating quick matching of storage and maintenance for different models.
The metal surface is laser-engraved with part numbers， resistant to diesel immersion and repeated wiping without code loss， enabling quick identification of equipment models during inventory， maintenance， and equipment model verification， avoiding incorrect installation and resulting in inconsistent fuel pressure.
The top is equipped with a transparent dust-proof protective cap， providing full protection for the precise working surface throughout the process.
The piston outlet end is equipped with a plastic protective cap， isolating dust and impurities during storage， transportation， disassembly， and maintenance， preventing fine particles from scratching the precisely ground surface of the piston， reducing assembly-related wear faults.
Factory complete set of matching detection， no need for on-site adjustment after replacement
Each set of piston and spring is independently tested on the machine for stroke， pressure， and sealing performance， with unified parameters， and after assembly， it directly restores the standard fuel supply pressure of the oil pump， significantly reducing maintenance and debugging time. Applicable scenarios
It is suitable for large mining excavators with single pump injection system, heavy-duty wheeled loaders, and high-power fixed diesel generators. It is applicable for 24-hour continuous heavy-duty operations in mines, continuous high-temperature vibration of the engine cabin, and heavy-duty diesel engines with poor-quality diesel containing dust and impurities. It is used for replacing the core components of the single pump booster in heavy-duty diesel engines.
Product basic parameters
Product name: 4P9827 Single Pump Piston Assembly
Part number: 4P9827
Main material: Tempered hardened alloy steel piston, high-temperature resistant alloy high-pressure spring, oil-resistant fluorine rubber sealing ring, plastic dust-proof protective cap
Structural features: Mirror-polished piston body, thickened high-pressure reset spring, black sealing positioning ring, transparent dust-proof cap at the top, identification code engraved on the outer wall
Application conditions: Ultra-high pressure reciprocating compression for fuel supply, high-temperature vibration of the engine cabin, corrosion by impure diesel in heavy-duty diesel engines with single pump
Product status: New complete set of piston assemblies, factory completed with full set of bench tests for clearance, high-pressure sealingity, and spring elasticity durability
Packaging: Single independent hard tube packaging, both ends protected to prevent磕碰划伤 the precise working surface of the piston， supporting single-piece retail， bulk purchase in cases， and suitable for cross-border small items and bulk logistics.
