Chapter 5. HYDRAULIC AND PNEUMATIC EQUIPMENT

TM 750-245-4

CHAPTER 5

HYDRAULIC AND PNEUMATIC EQUIPMENT

Section I. INTRODUCTION

the hose is adequately "anchored" to prevent whiplash in

5-1. General

the event of failure.

This chapter orients the inspector to varied inspection

requirements of hydraulic and pneumatic assemblies

d. Equipment used in cleaning and testing

and piece parts. Certain items such as o-rings, gaskets,

processes shall be free from grease, lint, dust, and other

and flarings require in-process inspection. These items

foreign matter. Fluid containers and test equipment

normally cannot be inspected during final inspection.

should be tested regularly for excessive contamination.

5-2. Precautions During Testing

5-3. Inspection or Test

a. Generally, pneumatics involve the use of high

a. During final inspection, insure that all parts are

pressure air. Therefore, the testing of any component

properly assembled and functioning according to

which is subjected to high-pressure must be pressure

technical manual requirements. This includes pumps,

tested in an approved barricaded area following all

gages, reservoirs, and valves.

established safety precautions.

b. All air and gas receivers subject to a working

b. Hands, or other parts of the body, should never

pressure in excess of 500 psi will be hydrostatically

be used in high-pressure testing to "feel" for pressure

tested to a pressure at least 1.5 times the maximum

leaks, especially in hoses. These type leaks may cause

working pressure. All receivers in use will be given a

serious injury to the operating personnel. Leaks of this

hydrostatic test every 24 months or at anytime a

type should be checked by the use of a soap and water

receiver shows any evidence of bad dents, corroded

solution or submerged bath.

area, leakage, or other conditions that indicate

c. When testing high-pressure hoses, insure that

weakness which might render the receiver unsafe.

Section II. HYDRAULIC COMPONENTS

5-6. Final Inspection

5-4. General

Hydraulics is the science of applied pressure to a fluid

a. Operational Test.

for emission of a working force in a closed system. Six

(1) Component under test will be connected

basic components make a complete working system

as prescribed in the hydraulic test stand procedures and

(reservoir, fluid, pump, pressure valve, directional valve,

subjected to tests specified in the technical manual for

and working component).

the item being tested.

(2) Surfaces must pass a wipe test to

5-5. In-Process Inspection

supplement visual inspection. Surfaces shall be free, in

a. Assemblies and parts shall be free from dirt,

addition to the above, from fingerprints, perspiration, or

corrosion, oil, grease, and similar foreign residues.

other acid or alkaline residues.

b. Whenever practicable, internal parts of

(3) During operation, inspection shall be

assemblies shall be thoroughly cleaned prior to

made to determine that various functions are

assembly.

accomplished satisfactorily, the movement of all

c. Hand tools and other equipment used in

components is 'smooth, and all tubing, fitting joints, and

cleaning and testing processes shall be free from

external seals are free from leaks.

grease, lint, dust, and other foreign matter. Fluid

b. Visual Inspection.

containers and test equipment shall be tested regularly

(1) Lines and hoses.

for excessive contamination.

(a) Cracks

d. Insure that o-rings, gaskets, and seals have no

(b) Dents

paint on any surface. Insure adequate shelf-life where

necessary.

Also, insure that o-rings are properly

(d) Leaks

installed and that back-up rings are used where needed.

(e) Contamination

(f) Corrosion

5-1