97931 Mercury TUBING, (4.00 Inches)

Introduction
The following procedure details the flushing and pickling process. This instruction will also show the requirements for cleanliness that are related to the engine piping that is external to the engine and the auxiliary equipment. This procedure should be used as a guideline.This entire Special Instruction should be read and understood before beginning any work on the engine.Flushing Information And Guidelines
General
The quality of the medium that is used for flushing is essential. The medium's quality ensures the performance and the long life of the Caterpillar Engine and the auxiliary equipment. The following items are needed in order to get proper performance from the equipment:
a well designed system
a flushing medium of good qualityThese prerequisites are useless unless the engine piping is initially cleaned in order to prevent equipment damage during the initial start-up. The piping must also be cleaned in order to remove any debris that may have been dislodged in the piping.Cleaning and flushing the new engine piping and the existing engine piping is accomplished by using essentially the same procedure. Contaminants that are introduced during the manufacturing, storage, and installation of the new engine piping must be removed. The flushing of the existing piping removes contaminants that are generated during normal operation, failures, and debris that is introduced during an overhaul. Do not flush the valves, the instrumentation, or the other critical components. If necessary, use temporary bypasses.All of the cleaning and flushing procedures must be done with the agreement from the equipment manufacturer, the installer, the operator, and the flushing medium supplier. No portion of these procedures should be done without a thorough understanding of the possible effects of improper preparation of the system. The installation, cleaning and flushing of the engine piping must not be done by someone without experience.Flushing Program For The Engine Piping
For a system that is assembled in the field, the ability to keep the piping sufficiently clean so that flushing is not necessary is not economical or practical. The flushing must take place after the installation of the system is complete. This must be done prior to the start-up of the system. The success of the flushing depends on the following items:
the success of the initial efforts to keep the particles out
the proper attention to flushing
the design of the systemIf the flushing is successful, a clean pipe and system components are obtained without damage to the equipment from debris.Keeping the particles out of the engine piping from the beginning will make cleaning the piping easier. This is achieved through the work of many people. The following items are examples of these efforts:
The design of the system should allow the system to be cleaned successfully.
The piping and equipment should be properly cleaned and maintained prior to installation.
Contaminants should be prevented from entering the piping during modifications.This list is not nearly complete. This list shows that the manufacturer, the sender, the installer, and the operator help to ensure that no contaminants enter the piping or the equipment. The preventive efforts make the flushing procedure easier, safer, shorter, and less costly.The success of flushing depends on the ability of the pump to provide a substantial flow rate. This creates a turbulent flow within the engine piping.Note: The turbulent flow will be maintained when the Reynolds number exceeds 20,000.If necessary, an outside pump is recommended in order to achieve this flow. The velocity of the medium moving through the engine piping is the most important part of successful flushing. The velocity should be two or three times the normal velocity in the system.Solids may be loosened by vibrations at pertinent points in the engine piping. The following points should be considered:
welded joints
flanges
bends
low points beneath a weld
locations of past work on the systemAfter the solids are broken loose, the solids will settle in the main tank or the foreign matter will be trapped by the temporary screens. The solids can be filtered out of the system by the user's bypass or by the full flow filtration system.It is not normally necessary to flush through certain systems and devices that have been assembled, cleaned, and sealed before the shipment to the site. Such equipment must be carefully protected against contaminants. During flushing, this equipment should be bypassed.For assemblies that can be flushed freely, this flushing procedure does not have the ability to flush out all possible contaminants. During the installation of the system, carefully prevent the contamination of unnecessary impurities that cannot be easily removed by flushing. These contaminants will cause problems in subsequent operations when the contaminants are dislodged by vibration or operation.The system will be flushed prior to start-up, but harmful contamination may enter the system during assembly.Preparation Of The Engine Piping For Flushing
Prior to flushing the engine piping, thoroughly inspect all accessible areas. If any evidence of contamination is found, the contamination should be removed manually.The cleanliness of the engine piping is always questionable. All leads must be blanked as close as possible to the engine and auxiliary equipment. Bypasses may be installed on the engine and auxiliary equipment. The bypasses should only bypass small sections of the piping and the flow path. All other areas in the engine piping that should not be flushed must be blanked with numbered plates. At the end of the flushing, ensure that all of the plates that were installed are removed.In the engine piping, install temporary strainers of 80 to 100 mesh on the suction side of the flushing pump. Install fine mesh strainers on the discharge side of the pressure source upstream of the flushing tank. The mesh should be no finer than 100 mesh. Use the auxiliary filters that are not reactive in order to increase the rate of the filtration. The filters also decrease the maximum particle size of the contaminants in the flushing medium.When a heater for the flushing medium has not been installed or when the heater is inadequate, supply heat to the flushing medium with the aid of the electrical heaters that are in the tanks. Sending hot water through the