Chapter 1. INTRODUCTION - TM-55-4940-353-13-P0004

TM 55-4940-353-13&P

CHAPTER 1

INTRODUCTION

SECTION I. GENERAL INFORMATION

1-2.

Scope. The test unit is suitable for conducting

1-1.

General. This manual provides the information

necessary to install, operate and maintain the Model 321

proof pressure and leakage test on aircraft and missile

Hose Tester designed and built by Avitech Inc. The

hose assemblies which conform to MIL-H-8788, MIL-H-

Hose Tester has been assigned P/N 321A, NSN 4940-

8790, and MILH-8795.

01-064-5057.

SECTION II. DESCRIPTION AND LEADING PARTICULARS

1-3.

Description. The P/N 321A Hose Tester

the test oil to the desired level. The noise created by

the air being exhausted from the pump is reduced to a

consists of a five and one-half gallon oil reservoir, an

reasonable level by a pneumatic muffler installed in the

air-operated pump, pressure gages, control valves, and

air exhaust port of the pump.

adaptors interconnected to supply, measure, and control

the delivery of high pressure oil to the hose under test.

At the completion of the test the oil is returned to the

1-5.

Reservoir. Test oil which conforms to MIL-H-

reservoir for reuse.

5606 or MIL-H-82382 is stored in the five and one-half

gallon aluminum reservoir. The 12-inch long x 9-inch

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Air-Operated Pump. The pressure of the oil

wide x 12-inch high reservoir acts as a base for the

Hose Tester, and all the other components are mounted

discharged from the pump is directly proportional to the

to it. The reservoir is provided with a sight gage which

input pressure of the operating air. In this case, the ratio

shows the full level, and a fillvent strainer is mounted on

is 150:1. A shop air supply of 50 standard cubic feet per

the top surface. A 10-micron oil filter is installed within

minute (scfm) at a gage pressure of 100 pounds per

the reservoir on the oil supply line to the pump. The

square inch (psig) must be available to operate the

element of this filter is replaceable.

pump.

1-6. Instrumentation. The operating air pressure is

The input air is filtered through an air filter built into the

Hose Tester and the pressure controlled by a pressure

measured by a 0 to 160 psi air gage connected in the air

regulator. The air then passes through a lubricator

regulator outlet, prior to the lubricator. The test oil

before being directed to the pump. The air actuates a

pressure

piston in the pump which in turn raises the pressure of

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