Page 418 - Cat4800-Oct2011

404 Parker Industrial Hose Customer Service
866 810 HOSE (4673) 800 242 HOSE (4673)
Strongsville, OH South Gate, CA
Eastern USA Western USA
www.safehose.com
e-mail: indhose@parker.com
Safety & Technical Information
Hose produced by this method is supported on a rigid
metal mandrel and is handled horizontally during
production. While a rigid mandrel limits the hose length,
it ensures good control of the inside diameter. It also ofers
sufcient support to the tube that either wire or textile
reinforcement may be applied at high tensions, which is
necessary in high pressure constructions. After the cover
is applied, the hose may be wrapped with nylon tape for
curing, giving the familiar “wrapped” fnish to the cover.
Typical Size Range: 3/4" ID and larger
Typical Uses: Air, chemical and petroleum transfer, LPG,
steam, water
Advantages: Close tolerances on inside diameter, high
pressure ratings, good length stability
Disadvantages: Higher cost than non-mandrel; lengths
restricted to length of mandrels
Basic Hose Constructions
Construction Elements
A hose is generally composed of three elements, each with
an important role in the overall performance of that hose.
Te three elements are:
Te Tube must be compatible with and able to contain
the media being conveyed. Many diferent materials are
used for tube construction, depending upon the media
the hose is designed to transmit.
Te Reinforcement is the strength member of the hose.
It enables the hose to withstand internal and external
pressure and abuse. Te reinforcement may be applied by
several methods, and consists of synthetic yarns, wire or a
combination of these. If suction or vacuum capability is a
requirement, a helixwiremay be part of the reinforcement.
Te Hose Cover protects the reinforcement from abuse or
damage. Te cover is usually a rubber compound selected
for its resistance to the environment, although, in some
cases (fre hose) the reinforcement will also act as the
cover. Typical considerations in selecting a cover stock are
the need to resist abrasion, ozone, weather and sunlight,
chemical or oil spillage, etc.
Construction Methods
Several methods are used to manufacture Parker hose.
Application factors such as size and pressure requirements
determine the selection of any particular hose style. Te
following is a description of the various construction
methods employed by Parker.
Non-Mandrel
Non-mandrel hose is constructed by passing long lengths
of extruded tube material through a machine which adds
the reinforcement in braided or spiraled layers. In this
method, the hose is not built on a mandrel, therefore
lengths are not restricted to the lengths of the mandrels.
Typical Size Range: 1-1/2" ID and smaller
Typical Uses: Air, water or general purpose service where
operating conditions are not severe
Advantages: Economy and long lengths
Disadvantages: Requireswider IDandODtolerance range
than mandrel made hose, limited pressure capabilities
Rigid Mandrel