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The
precautions below are important to be read and understood before designing
into a system any MAC valve, and before installing or servicing any
MAC valve. Improper use, installation or servicing of any MAC valve
in some systems could create a hazard to personnel or equipment.
Application Precautions:
INDUSTRIAL
USE -
MAC valves are intended for use in industrial pneumatic and/or vacuum
systems. They are not intended for consumer use or service. They
are general purpose industrial valves with literally thousands of
different applications in industrial systems. These products are
not inherently dangerous, but they are only a component of an overall
system. The system in which they are used must provide adequate
safeguards to prevent injury or damage in the event failure occurs,
whether it be failure of switches, regulators, cylinders, valves
or any other component.
POWER PRESSES -
MAC valves are not designed nor intended to be used to operate and/or
control the operation of clutch and/or brake systems on power presses.
There are special products on the market for such use.
2-POSITION VALVES -
Some MAC valves are 2-position, 4-way valves. When air is supplied
to the inlet port(s) of these valves, there will always be a flow
path from the inlet to one of the outlets regardless of which of
the two positions the valve is situated. Therefore, if pressurized
air retained in the system would present a hazard in the application
or servicing of the valve or system, a separate method in the system
must be provided to remove the trapped air.
3- POSITION VALVES -
Some MAC valves are 3-position, 4-way valves. These valves are either
double solenoid or double remote air operated. If either of the
two operators is in control, air supplied to the inlet port(s) will
pass through the valve to one of the outlets as on 2-position, 4-way
valves. However, if neither operator is in control, the valve moves
to a center position. Listed below are the various center position
functions :
A. CLOSED CENTER-
With this type valve, when in the center position all ports are
blocked (inlets and exhausts) meaning the air at both outlet ports
is trapped. If trapping the air in both outlet ports would present
a hazard in the application or servicing, a separate method in the
system must be provided to remove the trapped air or this type valve
should not be used.
B. OPEN CENTER-
With this type valve, when in the center position, the inlet port(s)
is blocked and the two outlet ports are open to the exhaust port(s)
of the valve. If having no air in either outlet
port would present a hazard in the application or servicing, this
type valve should not be used.
C. PRESSURE CENTER-
With this type valve, when in the center position, the inlet port(s)
is connected to both outlet ports of the valve. If having pressurized
air to either or both outlet ports would present a hazard in the
application or servicing of the valve or system, a separate method
in the system must be provided to remove the retained air.
OPERATING SPECIFICATIONS -
MAC valves are to be installed only on applications that meet all
operating specifications described in the MAC catalog for the valve.
MANUAL OPERATORS -
Most MAC valves can be ordered with manual operators. Manual operators
when depressed, are designed to shift the valve to the same position
as would the corresponding solenoid or remote air pilot operator
if it were activated. Care must be taken to order a type, if any,
that will be safe for the physical location of the manual operator
in the system.
Accidental
activation of a manual operator could create a
dangerous situation. If intentional or accidental operation of a
valve by a manualoperator could create a dangerous situation then
the "no operator" option should be used.
REMOTE AIR OPERATED VALVES
Pilot valves supplying signal pressure to remote air operated valves
should be 3-way valves with adequate supply and exhaust capacity
to provide positive pressurizing and exhausting of the pilot supply
line. Pilot lines should be open to exhaust when valves are deenergized.
Installation Precautions:
A.
Do not install MAC valves on a machine without first turning off
air (bleed system completely) and electricity to the machine.
B.
MAC valves should only be installed by qualified, knowledgeable
personnel who understand how the specific valve is to be pneumatically
piped and electrically connected (where applicable). Flow paths
through the valve are shown in the catalog and on the valve by use
of ANSI or ISO type standard graphic symbols. Do not install unless
these symbols and the valve functions and operations are thoroughly
understood.
Service Precautions:
A.
Do not service or remove from service any MAC valve without first
shutting off both the air and electricity to the valve and making
certain no pressurized air which could present a hazard is retained
in the system.
B.
MAC valves should only be serviced or removed from service by qualified,
knowledgeable personnel who understand how the specific valve is
piped and used and whether there is air retained in the connecting
lines to the valve or electric power still connected to the valve.
C.
MAC valves are never to be stepped on while working on a machine.
Damage to the valve, or lines to the valve (either air or electrical
lines) or accidental activating of a manual operator on the valve
could result in a dangerous situation.
Warning:
Under
no circumstances are Mac valves to be used on power presses for
air clutch and/or brake operations where failure of the valve to
operate as intended could in any way jeopardize the safety of the
operator or any other person. Under no circumstances are Mac valves
to be used in any circuit or in any manner intended to prevent unintended
operation of any machinery or other equipment where failure of the
valve to operate as intended could jeopardize the safety of the
operator or any other person. Air valves are not safety devices
nor should they be used in safety systems of any type.
Limitation
of Guarantee:
This
Guarantee is limited to the replacement or rebuilding of any valve
which should fail to operate properly. Valves, under the MAC Guarantee,
must be returned (with or without bases) transportation prepaid
and received at our factory within the Guarantee period. They will
be returned to the customer at the expense of MAC Valves, Inc.,
and will carry the same guarantee as provided under the Flat Rate
Rebuild Program.
Disclaimer of Guarantee:
No
claims for labor, material, time, damage, or transportation are
allowable nor will any valve be replaced or rebuilt under this guarantee
which has been damaged by the purchaser not in the normal course
of its use and maintenance during the warranty period. The guarantee
does not apply to loss or damage caused by fire, theft, riot, explosion,
labor dispute, act of God, or other causes beyond the control of
MAC Valves,Inc. MAC Valves, Inc. shall in no event be liable for
remote, special or consequential damages under the MAC Guarantee,
nor under any implied warranties, including the implied warranty
of merchantability.
The above Guarantee is our manner of extending the engineering and
service resources of the MAC Valves, Inc. organization to assure
our customer long, and continued satisfaction.
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