Significance and Use
4.1 Proper fluid condition is essential for the satisfactory performance and long life of the equipment. Prerequisites for proper lubrication and component performance are: (1) a well-designed hydraulic system, (2) the use of a suitable fluid, and (3) a maintenance program including proper filtration methods to ensure that the fluid is free of contaminants. These prerequisites are meaningless unless the hydraulic system is initially cleaned to a level that will prevent component damage on initial start up or when debris may be dislodged by any system upset.
4.2 The cleaning and flushing of both new and used systems are accomplished by essentially the same procedure. In new systems, the emphasis is on the removal of contaminants introduced during the manufacture, storage, field fabrication, and installation. In used systems, the emphasis is on the removal of contaminants that are generated during operations, from failures that occur during operation; or contaminants introduced during overhaul. Both new and used systems may benefit from high velocity flushing to remove materials that can collect in hard to drain pockets or normally non-wetted surfaces.
4.3 While the flushing and cleaning philosophies stated in this practice are applicable to all primary and servo hydraulic systems, the equipment specified herein does not apply to compact systems that use relatively small volumes of fluid unless they are servo systems where it is economically justified.
4.4 It should be emphasized that the established procedures to be followed for flushing and cleaning the hydraulic systems should be accomplished through the cooperative efforts and agreement of the equipment manufacturer, the installer, the flushing service vendor, the operator, and the fluid supplier. No phase of these procedures should be undertaken without a thorough understanding of the possible effects of improper system preparation. The installation and cleaning and flushing of the equipment should not be entrusted to persons lacking in experience.
Scope
1.1 This practice covers aid for the equipment manufacturer, the installer, the oil supplier and the operator in coordinating their efforts towards obtaining and maintaining clean petroleum fluid hydraulic systems. Of necessity, this practice is generalized due to variations in the type of equipment, builder's practices, and operating conditions. Constant vigilance is required throughout all phases of design, fabrication, installation, flushing, testing, and operation of hydraulic systems to minimize and reduce the presence of contaminants and to obtain optimum system reliability.
1.2 This practice is presented in the following sequence:
|
| Section |
| Scope | 1 |
| Referenced Documents | 2 |
| Terminology | 3 |
| Significance and Use | 4 |
| Types of Contamination | 5 |
| General | 5.1 |
| Water | 5.2 |
| Soluble Contaminants | 5.3 |
| Insoluble Contaminants | 5.4 |
| Lodged Contamination | 5.4.2.1 |
| Suspended or Loose Contamination | 5.4.2.2 |
| Contamination Control | 6 |
| General | 6.1 |
| Initial Filling | 6.1.1 |
| In-Service Units | 6.1.2 |
| Connection of Contamination Control System | 6.1.3 |
| Piping or Tubing Contamination Control System | 6.1.4 |
| Contamination Control Procedures | 6.2 |
| Full Flow Contamination Control | 6.2.1 |
| Bypass Contamination Control | 6.2.2 |
| Batch Contamination Control | 6.2.3 |
| Contamination Control Processes | 6.3 |
| Gravity | 6.3.1 |
| Mechanical | 6.3.2 |
| Centrifuge | 6.3.2.1 |
| Filters | 6.3.2.2 |
| Supplementary Methods | 6.3.3 |
| Limitations of Contamination Control Devices | 6.3.4 |
| Storage | 7 |
| General | 7.1 |
| Inspection | 8 |
| General | 8.1 |
| System Components | 8.2 |
| Valves, Strainers, and Coolers | 8.2.1 |
| Sumps and Tanks | 8.2.2 |
| Control Devices | 8.2.3 |
| Pumps | 8.2.4 |
| Flushing Program | 9 |
| General | 9.1 |
| Preparation of System for Flushing | 9.2 |
| Fluid Heating Prior to Flushing | 9.3 |
| Selection of Flushing Oils | 9.4 |
| System Operation Fluid | 9.4.1 |
| Special Flushing Oil | 9.4.2 |
| Flushing Oil Selection Guide | 9.4.3 |
| Flushing Procedure for New Systems | 9.5 |
| Flushing Oil Charge | 9.5.1 |
| Cleaning of Filtration Devices | 9.5.2 |
| Cleaning of System Components | 9.5.3 |
| System Flushing and Flush Acceptance Criteria | 9.5.4 |
| Draining of Flushing Oil | 9.5.5 |
| Displacement Oil | 9.5.6 |
| Interim Corrosion Protection | 9.5.7 |
| New Fluid Charge | 9.5.8 |
| Flushing of Used Systems | 9.6 |
| General Guidelines | 9.6.1 |
| Procedure | 9.6.2 |
| System Maintenance | 10 |
| Preinstallation | 10.2 |
| In-Service Units | 10.3 |
| Decision to Flush In-Service Hydraulic Systems | 10.4 |
| Fluid Condition Monitoring | 11 |
| Fluid Sampling Techniques | 11.2 |
| Visual Inspection | 11.3 |
| Laboratory Analysis | 11.4 |
| Fluid Cleanliness Criteria | 11.5 |
| General Information | 12 |
| Centrifuge Ratings | 12.2 |
| Coalescence | 12.3 |
| Vacuum Dehydration | 12.4 |
| Adsorption | 12.5 |
1.3 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
