contains oil and significant amounts of water. This
Q9-10. Which of the following gauges is NOT a
gauge used on an A/M26U-4 nitrogen
limits your use of compressed air. For example, you
servicing trailer?
can't use it to purge oxygen equipment because of
oxygen purity standards and because mixing oil with
1.
The manifold pressure gauge
oxygen is an explosion hazard. You will learn more
2.
The low pressure output gauge
about this in the next chapter.
3.
The high pressure output gauge
4.
The manifold by-pass gauge
Cylinders for compressed air are painted black.
Those containing oil-pumped air have two green
Q9-11. What is the minimum pressure that should
stripes painted around the top of the cylinder; those
remain in a nitrogen cylinder on an
containing water-pumped air have one green stripe. A
A/M26U-4 nitrogen servicing trailer?
cylinder's last hydrostatic test date is stenciled across
1.
50 psi
the bottom of the cylinder.
2.
200 psi
Low-pressure air from portable, engine-driven,
3.
500 psi
support equipment is oil-pumped and has a high
4.
750 psi
moisture content. It cannot be used as a substitute for
Q9-12. The pump on the A/M26U-4 nitrogen
low-pressure nitrogen.
servicing trailer will stop automatically when
Q9-6. What is the maximum operating pressure that
the manifold pressure reaches what maximum
can be obtained from a portable nitrogen
pressure?
cylinder?
1.
2,500 psi
1.
2,400 psi
2.
3,000 psi
2.
2,800 psi
3.
3,500 psi
3.
3,000 psi
4.
3,750 psi
4.
3,500 psi
Q9-13. In the motor and pump assembly, which of the
Q9-7. What is the total number of nitrogen cylinders
following components are least likely to fail?
on the A/M26U-4 nitrogen servicing trailer?
1.
Pressure regulator
1.
One
2.
Relief valves
2.
Two
3.
Piston
3.
Five
4.
Spool
4.
Six
Q9-14. Which of the following discrepancies could be
Q9-8. What is the maximum pressure allowed for a
a probable cause for the pump not cycling or
nitrogen bottle on the A/M26U-4 nitrogen
cycling slow?
servicing trailer?
1. Defective piston
1.
2,400 psi
2. Motor selector valve improperly
2.
3,000 psi
positioned
3.
3,500 psi
3. Rod seals are leaking
4.
4,000 psi
4. Defective spool
Q9-9. Which of the following valves is used only
Q9-15. The hydrostatic test dates of the nitrogen
when recharging the cylinders on the
cylinders should not exceed what number of
A/M26U-4 nitrogen servicing trailer?
years?
1.
The manifold by-pass valve
1.
5
2.
The manifold shutoff valve
2.
3
3.
The lever control valve
3.
7
4.
The pump inlet valve
4.
10
9-20
