VICI 450 Dynacalibrator - Manual (Page 16)

12
Supply Inlet
All Dynacalibrators except those with -1X input configurations (separate carrier and
dilution inlet ports) are equipped with a supply inlet fitting. Those with -0X input
configurations (no internal pump) must have the supply inlet connected to an
external pressurized source of carrier and dilution gas, such as an external pump, a
cylinder of compressed gas, etc. The most commonly used gas is dry air; however,
dry nitrogen or any other comparably inert gas including ambient air may also be used.
The pressure of the external gas source connected to
the supply inlet must be at least 10 psig but no more
than 15 psig. High pressure pumps and gas cylinders are
potentially very dangerous. Exercise care when breaking
connections between the Dynacalibrator and external gas
supplies. The source should be valved OFF and time allowed for
downstream pressure to equilbrate before breaking fittings.
On all units with an internal pump, the supply inlet port is internally connected
directly to the suction side of the pump. Since the output of the pump is
equipped with a particulate filter and activated-charcoal scrubbers, the supply
inlet port should normally be left unconnected, completely open, and clear of any
obstructions, ex cept as noted below for dusty environments.
If you need to alter the carrier and/or dilution streams by adding filters, scrubbers,
dehydrators, etc., the recommended method is to connect these components
in series with the bypass loops as described on the next page. If your unit is not
equipped with bypass loops, you must consider the following before altering the
stream into the supply inlet:
• If the unit or device connected to the supply inlet port generates a gas-flow-
related pressure drop, thereby partially “starving” the pump (that is, increasing
the vacuum at the pump’s suction port), the maximum flow output capability
of the Dynacalibrator will likely be diminished.
• If the unit or device connected to the supply inlet is equipped with a supple-
mentary pump providing an altered gas flow to the Dynacalibrator pump’s
suction at a pres sure greater than 0 psig, the life of the pump may be
decreased. Increasing the suction pressure of the Dynacalibrator pump
will not increase its output flow capability.
Whenever a Dynacalibrator is to be operated in an environment that has signifi-
cant concentrations of dust or other particulate matter, we rec ommend a VICI
Metronics Particulate Filter Assembly (PFA) connected to the supply inlet port.
The disposable filter inside the PFA has been selected for its very low pressure
drop. Use of a PFA will not diminish the output flow of the Dynacalibrator pump.
The disposable filter part number is FC.
VICI recommends that Dynacalibrators equipped with inter-
nal pumps be operated either with their SUPPLY INLET port
completely open and clear of obstructions or fitted with a
low pressure drop VICI Metronics Particulate Filter Assembly.
Carrier/Dilution Inlets
All Dynacalibrators with input configurations -1X, -3X, -4X and -5X have a carrier
inlet and/or a dilution inlet. The -1X configuration does not have an internal pump,
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