FUEL PRESSURE

TM 55-4920-416-13

Section IV

NAVAER 17-15C-539

Paragraphs 4-19 to 4-24

(ac or dc) is applied to this receptacle as required. In

4-22. ALTIMETER AND RATE OF CLIMB (5, figure 4-3). This

conjunction with the power cables, its internal wiring

connection is used for testing altimeters and rate-of-climb

automatically adjusts the circuit of the test set to operate from

indicators; for connection to the static side of airspeed

the power supplies specified in Section I, Table 1-2.

indicators when checking at altitudes other than sea level, and

for checking Mach meters.

It is usually convenient to

4-19. FUEL PRESSURE (2, figure 4-3). This connection is

simultaneously test the altimeter, rate-of-climb meter, and

used only when testing fuel pressure gauges rated up to 25

airspeed indicator by connecting up two hoses to the last two

psig.

connectors (4 and 5).

4-20. MANIFOLD PRESSURE (3, figure 4-3). This connection

4-23. OPERATION PROCEDURES.

is used when testing manifold pressure gauges covering the

range from 10 to 75 inches of Hg absolute.

4-24. PRE-OPERATION. Special hydraulic oils are required

for the proper operation of VPT-7A, depending upon

4-21. AIRSPEED (4, figure 4-3). This connection is used

environmental conditions.

For details see Section II,

when testing and calibrating airspeed indicators calibrated in

paragraph 3-5. Whenever the VPT-7A test set is used in cold

knots or miles per hour. When checking Mach meters this

weather, warm the set by operating the pump for not less than

connection must be used in conjunction with the altimeter

5 minutes, with both selector valves set at OFF and the

connection.

VACUUM and PRESSURE controls 1, 2, 3 and 4 fully

Figure 4-4. Pitot System Test