Page 276 - untitled

Parker Hannifin Corporation

Parflex Division

Ravenna, Ohio

270

Hydraulic &

Pneumatic

Hose & Fit.

PTFE

Hose &

Fittings

Thermoplastic

Tubing

Coiled Air Hose,

Fittings

& Accessories

Truck (Fleet)

Products

Tooling &

Equipment

Hose

Accessories

Technical &

Design

Information

Approvals &

Guides

Alphanumeric

Index

Selection, Installation & Maintenance

5.24 Hose Movement and Bending –

Hose allows relative

motion between system components. Analyze this motion

when designing hose systems. The number of cycles per day

may significantly affect hose life. Also avoid multiple planes of

motion and twisting motion. Consider the motion of the hose

when selecting hose and predicting service life. In applications

that require hose to move or bend, refer to Figures 6 and 7;

and use these practices:

5.24.1 Bend in Only One Plane to Avoid Twisting

FIGURE 6 — BEND IN ONLY ONE PLANE

TO AVOID TWISTING

5.24.2 Prevent Hose Bending in More Than One Plane –

If

hose follows a compound bend, couple it into separate

segments, or clamp into segments that flex in only one plane.

FIGURE 7 — PREVENT HOSE BENDING IN

MORE THAN ONE PLANE

6. Hose-Assembly Fabrication –

Persons fabricating hose

assemblies should be trained in the proper use of equipment

and materials. The manufacturers’ instructions and the

practices listed as follows must be followed. Properly

assembled fittings are vital to the integrity of a hose assembly.

Improperly assembled fittings can separate from the hose and

may cause serious injury or property damage from whipping

hose, or from fire or explosion of vapor expelled from the hose.

6.1 Component Inspection –

Prior to assembly, examine

components for:

A.

Style or type

B.

Cleanliness

C.

Loose covers

D.

Nicks

E.

Size

F.

Inside obstructions

G.

Visible defects

H.

Damage

I.

Length

J.

Blisters

K.

Burrs

6.2 Hose Fittings –

Hose fitting components from one

manufacturer are not usually compatible with fittings

components supplied by another manufacturer. For example,

do not use a hose fitting nipple from one manufacturer with a

Incorrect

Correct

Incorrect

Correct

hose socket from another manufacturer. It is the responsibility

of the fabricator to consult the manufacturer’s written

instructions or the manufacturer directly for information on

proper fitting components.

6.3 Hose and Fitting Compatibility –

Care must be taken to

determine proper compatibility between the hose and fitting.

Base selection on the manufacturers’ recommendations

substantiated by testing to industry standards such as

SAE J517. Hose from one manufacturer is not usually

compatible with fittings from another. Do not intermix hose

and fittings from two manufacturers without approval from

both manufacturers.

6.4 Hose Assembly Equipment –

Assembly equipment from

one manufacturer is usually not interchangeable with that

from another manufacturer. Hoses and fittings from one

manufacturer should not generally be assembled with the

equipment of another manufacturer.

6.5 Safety Equipment –

During fabrication, use proper safety

equipment, including eye protection, breathing

apparatus, and adequate ventilation.

6.6 Reuse of Hose and Fittings –

When fabricating hose as-

semblies, do not reuse:

A.

Field-attachable fittings that have blown or pulled off

hose.

B.

Any part of hose fittings that were permanently

crimped or swaged to hose.

C.

Hose that has been in service after system check out

(see 7.7).

6.7 Cleanliness of Hose Assemblies –

Hose assemblies may

be contaminated during fabrication. Clean hoses to specified

cleanliness levels (see 5.13).

7. Hose Installation and Replacement –

Use the following

practices when installing hose assemblies in new systems or

replacing hose assemblies in existing systems:

7.1 Pre-Installation Inspection –

Before installing hose as-

semblies, examine:

A.

Hose length and routing for compliance with original

design.

B.

Assemblies for correct style, size, length and visible

nonconformities.

C.

Fitting sealing surfaces for burrs, nicks, or other

damage.

NOTE:

When replacing hose assemblies in existing systems,

verify that the replacement is of equal quality to the original

assembly.

7.2 Handling During Installation –

Handle hose with care dur-

ing installation. Kinking hose, or bending at less than

minimum bend radius may reduce hose life. Avoid sharp

bending at the hose/fitting juncture (see 5.21).

7.3 Twist Angle and Orientation –

Pressure applied to a

twisted hose may shorten the life of the hose or loosen the

connections. To avoid twisting, use the hose lay line or mark-

ing as a reference (see Figure 8).