2. Determine relief pressures and check for proper operation of each relief valve.
3. Accomplish a filter cooler changeover without causing startup of the standby pump.
4.
Demonstrate that control valves have suitable capacity，response， and stability.
5. Demonstrate the oil pressure control valve can control oil pressure.
Figure 4-9.Combinedseal，lube， and control oil system.
Vibration Measurements
The API Standard 670 covers the minimum requirements for noncontact-ing vibration in an axial-position monitoring system.
The accuracy for the vibration channels should meet a linearity of土5% of200 millivolts per mil (0.001 inch， 0.0254 mm) sensitivity over a minimumoperating range of 80 mils (2.032 mm). For the axialposition， the channel linearity must be土5% of 200 millivolts per mil sensitivity and a土1.0 mil of a straight line over a minimum operating range of 80 mils (2.032 mm). Temperature should not affect the linerarity of the system by more than 5% over a temperature range of -30 to +350 oF(-34.4to +176.7 oc) for the probe and extension cable. The oscillator demodulator is a signal condition-ing device powered by -24 volts of direct current. It sends a radio frequency signal to the probe and demodulates the probe output. It should maintain linearity over the temperature range of -30 to +150 oF(-34.4to +65.6 oc). The monitors and power supply should maintain their linearity over a temperature range of -20 to +150 oF(-28.9to +65.6 oc). Theprobes，cables， oscillator demodulators， and power supplies installed on a single train should be physically and electrically interchangeable.
The noncontacting vibration and axial position monitoringsystem， con-sisting ofprobe， cables， connectors， oscillator demodulator， power supply， and monitors. The probe tip diameters should be 0.190-0.195 inches (4.8-
4.95 mm) with body diameters of 1j4 (6.35 mm) -28 UNF -2A threaded， or 0.3-0.312 inches (7.62-7.92 mm) with a body diameter of 3j8 (9.52 mm) -24 UNF -24A threaded. The probe length is about 1 inch long. Tests conducted on various manufacturer.s probes indicate that the 0.3-0.312-inch (7.62-7.92 mm) probe has a better linearity in most cases. The integral probecables have a cover of tetra-flouroethylene， a flexible stainless steelarmoring， which extends to within four inches of the connector. The overall physical length should be approximately 36 inches (914.4 mm) measured from probe tip to the end of the connector. The electrical length of the probe and integral cable should be six feet. The extension cables should be coaxial with electrical and physical lengths of 108 inches (2743.2 mm). The oscillator demodulator will operate with a standard supply voltage of -24 volts dc and will be calibrated for a standard electrical length of 15 feet (5 meters). This length corresponds to the probe integral cable and extension. Monitors should operate from a power supply of 117 volts土5% with the linearity requirements specified. False shutdown from power interruption will be prevented regard-less of mode or duration. Power supply failure should actuate an alarm.
The radial transducers should be placed within three inches of the bearing， and there should be two radial transducers at each bearing. care should be taken not to place the probe at the nodal points. The two probes should be mounted 90o apart (土5o)at a 45o (土5o) angle from each side of the verticalcenter. Viewed from the drive end of the machinetrain， the x probe will beon the right side of the vertical， and the . probe will be on the left side of the vertical. Figures 4-10 and 4-11 show protection systems for a turbine and a gear box respectively.
The axial transducers should have one probe sensing the shaft itself within 12 inches (305 mm) of the active surface of the thrust collar with the other probe sensing the machined surface of the thrust collar. The probes should be mounted facing in opposite directions. Temperature probes embedded in the bearings are often more useful in preventing thrust-bearing failures than
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