Figure 4-2.Typical Intercooler Tubes and Safety Valves.

TM 5-3895-374-24-2 The standard inlet air filter is suitable only for normal industrial applications. Should the compressor be located in an area where the atmosphere contains a heavy concentration of dust and dirt, an air filter utilizing a specially designed, heavy duty (4 micron) element should be used. All applications of this nature should be referred to the nearest Ingersoll-Rand sales office or distributor. INTERCOOLER This compressor is equipped with an intercooler between the first-stage and the second-stage See Figure 4-2. The purpose of the intercooler is to remove most of the heat of the first-stage compression from the air before It enters the second-stage, thus improving efficiency and decreasing the final discharge air temperature. The intercooler consists of one or more finned tubes connecting the discharge of the first-stage to the inlet of the second stage. The compressed air flows through these tubes and its heat is transferred to the cooling fins, where the air from the belt wheel fan passing over the fins dissipates the heat to atmosphere. Never permit the air flow to these tubes to become obstructed, and clean the surfaces of the tubes whenever deposits of oil, dirt or grease are observed. Use a non- flammable safety solvent for cleaning purposes. During regular overhaul periods, the tubes should be removed from their headers and inspected internally. If the interior of the tubes requires cleaning, cap one end and fill it with a non- flammable safety solvent to help loosen internal deposits of oil, dirt and carbon. Always flush the tubes with warm water and permit them to dry thoroughly before replacing. Figure 4-2.Typical Intercooler Tubes and Safety Valves. SAFETY VALVE Safety Valves are designed to protect against damage from over pressure. This compressor will be furnished with the following ASME approved safety valves. 1. Intercooler Safety Valve-The Model 7100 will be supplied with one 80 PSIG (5.6 kg/cm2) safety valve installed in the intercooler, and the Model 3000 will be supplied with two 80 PSIG safety valves installed in the intercooler. See Figure 4-2. 2. Receiver Safety Valve-Receiver mounted units will be supplied with a 200 PSIG (14.1 kg/cm2) safety valve installed in the receiver. 3. Discharge Safety Valve-On models that are supplied with an aftercooler or tank silencer a 325 PSIG (22.8 kg/cm2) safety valve is installed between the compressor discharge and the aftercooler/silencer. STARTING UNLOADING SYSTEM OPERATION OF STARTING UNLOADING SYSTEM - The purpose of the system is to relieve cylinder pressure when the compressor stops permitting it to start against a light load; increasing the life of the driver and belts and also reducing the possibility of tripping the overload relay. The system operates in the following manner: As shown in Figure 4-3, the centrifugal unloader is attached to Figure 4-3.Position of weight and thrust pin when compressor is stopped. This machine contains high pressure air. Can cause injury or death from flying parts. Do not remove change or make substitutions for the safety valves. They should be replaced only by genuine I-R replacement parts. . This machine contains high pressure air. Can cause injury or death from flying parts. Do not remove change or make substitutions for the safety valves. They should be replaced only by genuine I-R replacement parts. If a separate or detached air receiver is used, a properly rated ASME approved safety valve must be installed in the receiver. This machine contains high pressure air. Can cause injury or death from flying parts. Do not remove change or make substitutions for the safety valves. They should be replaced only by genuine I-R replacement parts. If an aftercooler or any other restriction is added to the compressor discharge, an ASME approved safety valve must be installed between the compressor discharge and the restriction. WARNING page 3-837