Download article - Manuli Hydraulics

FLUID POWER
116
bE On thE SaFE SIDE
… although, with the qsafe system, both sides of the hydraulic
coupling boast a 4:1 safety factor. not to mention simple connection
and the ability to cope with tough working conditions…
Many modern hydraulic machines
are purposely designed for flexibly
carrying out a variety of jobs using
interchangeable tools, not only in
agricultural applications, but increasingly
in construction as well. The technology
of quick-release couplings is universally
used for connecting and disconnecting
implements without the need to remove
the oil, and often while maintaining the
pressure in the hydraulic system.
Many factors have to be considered
while designing or selecting the most
appropriate product. There are two
main aspects that need to be addressed,
the first being the connection and
disconnection operation: in particular,
how easily and safely can this be
undertaken; how much effort is required
for the operation; what is its position on
the machine; and how much residual
pressure is there in the hydraulic circuit
before the connection?
The second area of concern covers the
severity of working and environmental
conditions after connection, in terms of
the working pressure, pressure and flow
impulses at high frequency, rapid backflows,
pressure drops, oil temperature
and various safety factors.
An appropriate analysis of all these
technical factors is therefore essential to
ensure the safety of the operators and
the performance of the applications.
Safety in numbers
Manuli Rubber Industries has recently
begun offering its integrated QSafe
programme, the new ‘Made in Manuli’
quick coupling family which allows the
connection of two parts of the hydraulic
circuit in a safe, accurate, fast and easy
manner. Under the Qsafe brand, the
company offers a complete highly
technological quick coupling range,
comprising approximately 31 families
with 1,000 items for agricultural and
forestry machines, construction and
utility vehicles, road transportation and
construction machines, materials
handling and lifting machines, and
other industrial applications.
iVT International Off-Highway 2011
Q.Safe agricutural application
MQS-DHI Direct Hose Integration
All Manuli products are designed
and validated to fit the constant need
for increased power in hydraulic systems:
P = p * Q,
where P = hydraulic power (kW), p =
pressure (bar) and Q = oil flow rate (l/
min), offering:
• The necessary resistance to static and
New MQS-FP male coupling is connectable under pressure
dynamic pressure to assure a long
service life;
• An appropriate fluid-dynamic design
of all internal parts to increase the oil
flow rate with reduced pressure drops.
Special solutions have been adopted
in all sealing systems (back-up rings,
polyurethane gaskets, high-temperature
materials, wash-out proof design) in
order to guarantee leak-free performance.
Field failures could easily result in
expensive machine breakdowns and
possible safety hazards. It is for that
reason preferable to over-engineer the
design of any component in order to
achieve testing failure modes far above
operational conditions.
The ratio of burst strength to
working strength is the safety factor.
Heavy-duty hydraulic applications
require a 4:1 safety factor, according to
all international standards and to the
best design practices of the sector.
The entire Manuli QSafe standard
programme is aligned to the 4:1 safety
factor, both in connected and in
disconnected conditions. All users of
commercial products should carefully
check this parameter, as it is often
smaller or not even reported in the
technical documentation.
Besides, thanks to their integrated
design and manufacturing process, the
QSafe products can perfectly match any

The Q.Safe range
Manuli hydraulic connector (compatible
materials strength, pressure performance,
tolerance chain, surface finish, etc),
extending the reliability and safety
requirements of individual components to
the whole port to port connection string.
The Manuli integrated approach can
really add to new solutions where the
performance of traditional separated
components can be compacted and
enhanced in innovative products. This
is the case of the new DHI QSafe family,
where the connect/disconnect function
has been integrated in the hose fitting
(Direct to Hose Integration), creating a
new patented product line that can offer
innovative features in terms of lightness,
compactness and fast assembly.
As part of Manuli Rubber Industries,
Manuli Hydraulics is also active in the
design, manufacture and sale of a wide
range of hoses, connectors and
machines for conveying power in high-
and very high-pressure hydraulic circuits
and fluids in refrigeration units. iVT
Paolo Seghi is CIO at Manuli Rubber with 30
years’ experience in the industry; Giuseppe Rusconi
works in Connectors Technical Marketing
and is experienced in the design
of quick coupling products
FLUID POWER
PaOLO SEghI & gIUSEPPE RUScOnI
New MQS-ARB push-pull – ideal for agriculture
MQS-DHI ISO A male coupling
CONTACT
www.manulirubber.com
info@manulirubber.com