Improving Contamination Control . . . 279
Storage of Components, Tools, and Test Equipment . . . . . . . . . 279
New Hoses . . . . . . . . . . . . . . . . . . . . . . . . . 280
Filtering New Oil . . . . . . . . . . . . . . . . . . . . . . . 282
Filter Carts . . . . . . . . . . . . . . . . . . . . . . . . . 282
Oil Sampling Ports . . . . . . . . . . . . . . . . . . . . . . 282
Hydraulic Cylinder Rod Protectors . . . . . . . . . . . . . . . . 282
Pressure Taps. . . . . . . . . . . . . . . . . . . . . . . . 283
Oil Drum Covers . . . . . . . . . . . . . . . . . . . . . . . 283
Reconditioning a Contaminated Hydraulic System . . . . . . . . . . 283
Chapter 13
Accumulators 293
Functions and Applications . . . 293
Store Energy . . . . . . . . . . . . . . . . . . . . . . . . 293
Dampen Pressure Spikes . . . . . . . . . . . . . . . . . . . 293
Ease the Buildup of Pressure . . . . . . . . . . . . . . . . . . 294
Maintain a Set Pressure . . . . . . . . . . . . . . . . . . . . 294
Recover Energy . . . . . . . . . . . . . . . . . . . . . . . 296
Types of Accumulators . . . 296
Spring . . . . . . . . . . . . . . . . . . . . . . . . . . . 298
Weighted. . . . . . . . . . . . . . . . . . . . . . . . . . 298
Gas . . . . . . . . . . . . . . . . . . . . . . . . . . . . 299
Accumulator Safety . . . 302
Service and Repair . . . 305
Checking Precharge Pressure with a Nitrogen Service Tool . . . . . . 305
Charging an Accumulator with Nitrogen . . . . . . . . . . . . . . 308
Measuring Precharge Pressure with a Hydraulic Oil Pressure Gauge . . . 310
Repair . . . . . . . . . . . . . . . . . . . . . . . . . . . 310
Tools and Accessories . . . 310
Gas Bottles . . . . . . . . . . . . . . . . . . . . . . . . . 311
Safety Fuse. . . . . . . . . . . . . . . . . . . . . . . . . 311
Nitrogen Charging Pumps . . . . . . . . . . . . . . . . . . . 311
Accumulator Energy Sensors . . . . . . . . . . . . . . . . . . 311
Hydraulic Hybrid Applications . . . 312
Series Hydraulic Hybrid . . . . . . . . . . . . . . . . . . . . 312
Parallel Hydraulic Hybrid. . . . . . . . . . . . . . . . . . . . 312
Hydraulic Hybrid Excavator. . . . . . . . . . . . . . . . . . . 312
Chapter 14
Reservoirs and Coolers 319
Reservoirs . . . 319
Housing . . . . . . . . . . . . . . . . . . . . . . . . . . 319
Receives and Dissipates Heat . . . . . . . . . . . . . . . . . 321
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