Page 277 - untitled

Parker Hannifin Corporation

Parflex Division

Ravenna, Ohio

271

Coiled Air Hose,

Fittings

& Accessories

Hydraulic &

Pneumatic

Hose & Fit.

PTFE

Hose &

Fittings

The

rmoplastic

Tu

bing

Truck (Fleet)

Products

Tooling &

Equipment

Hose

Accessories

Technical &

Design

Information

Approvals &

Guides

Alphanumeric

Index

Selection, Installation & Maintenance

FIGURE 8 — TWIST ANGLE AND ORIENTATION

7.4 Securement and Protection –

Install necessary

restraints and protective devices. Determine that such

devices do not create additional stress or wear points.

7.5 Routing –

Review proper routing practices provided in Sec-

tion 5 and make appropriate corrections to obtain

optimum performance.

7.6 Assembly Torque –

The connection end of a hose is

normally threaded to obtain a tight pressure seal when

attached to a port, an adapter, or another fitting. Sometimes

bolts or screws provide the threaded connection. Each size

and type of connection requires different torque values, and

these may vary due to type of material or exterior coating.

7.7 System Checkouts –

In hydraulic or other liquid systems,

eliminate all air entrapment after completing the installation.

Follow manufacturers’ instructions to test the system for

possible malfunctions and leaks.

7.7.1 To avoid injury during system checkouts:

A.

Do not touch any part of the system when checking for

leaks (see 4.1).

B.

Stay out of potentially hazardous areas while testing hose

systems (see Section 4).

C.

Relieve system pressure before tightening

connections.

8. Maintenance Inspection –

A hose and fitting maintenance

program may reduce equipment downtime, maintain peak

operating performance, and reduce the risk of personal injury

and/or property damage. The user should design and

implement a maintenance program that suits the specific

application and each specific hose in that application.

8.1 Inspection Frequency –

Evaluate factors such as the

nature and severity of the application, past history, and manu-

facturers’ information to establish the frequency of visual

inspections and functional tests.

8.2 Visual Inspection (Hose and Fittings) –

Visually inspect

hose and fittings for:

A. Leaks at hose fitting or in hose.

B. Damaged, cut or abraded cover.

C. Exposed reinforcement.

D. Kinked, crushed, flattened, or twisted hose.

E. Hard, stiff, heat cracked, or charred hose.

F. Blistered, soft, degraded, or loose cover.

G. Cracked, damaged, or badly corroded fittings.

H. Fitting slippage on hose.

I. Other signs of significant deterioration. If any of these

conditions exist, evaluate the hose assemblies for cor-

rection or replacement.

8.3 Visual Inspection (All Other Components) –

When visually

inspecting hose and fittings, inspect for related items includ-

ing:

A. Leaking ports.

B. Damaged or missing hose clamps, guards or shields.

C. Excessive dirt and debris around hose.

D. System fluid: Level, type, contamination, condition

and air entrainment. If any of these are found, address

them appropriately.

8.4 Functional Test –

Functional tests determine if systems

are leak free and operating properly. Carry out functional tests

per information from equipment manufacturers.

9. Hose Storage –

Age control and the manner of storage can af-

fect hose life. Use the following practices when storing hose.

9.1 Age Control –

Maintain a system of age control to deter-

mine that hose is used before its shelf life has expired. Shelf

life is the period of time when it is reasonable to expect the

hose to retain full capabilities for rendering the intended

service.

Store hose in a manner that facilitates age control and first-in,

first-out usage based on manufacturing date on hose or hose

assembly. Per SAE J517:

A.

Shelf life of rubber hose in bulk form, or in hose as-

semblies passing visual inspection and proof test, is

forty quarters (ten years) from the date of vulcaniza-

tion.

B.

Shelf life of thermoplastic and polytetrafluoroethylene

hose is considered to be unlimited.

9.2 Storage –

Store hose and hose assemblies in a cool,

dark, dry area with the ends capped. When storing hose, take

care to avoid damage that could reduce hose life, and follow

the manufacturers’ information for storage and shelf life.

Examples of factors that can adversely affect hose product in

storage are:

A.

Temperature

B.

Ozone

C.

Oils

D.

Corrosive liquids and fumes

E.

Rodents

F.

Humidity

G.

Ultraviolet light

H.

Solvents

I.

Insects

J.

Radioactive materials

If there are any questions regarding the quality or usability of

hose or hose assemblies, evaluate appropriately:

A.

Flex the hose to the minimum bend radius and com-

pare it with new hose. After flexing, examine the cover

and tube for cracks. If any appear, no matter how

small, reject the hose.

B.

If the hose is wire reinforced, and the hose is unusually

stiff, or a cracking sound is heard during flexing, check

for rust by cutting away a section of the cover from a

sample. Rust would be another reason for rejection.

C.

If doubt still persists, contact hose assembler to

conduct proof-pressure tests or any other tests needed

to verify hose quality.

Prepared by the SAE Fluid Conductors and Connectors Technical

Committee SC3–Training and Education Subcommittee

Incorrect

Correct