2.13.5
Pneumatic Low-Range Pressure Controllers for Ductwork Applications
Controllers shall provide two-pipe, pilot-operated control with pneumatic
feedback and proportional action. Sensing elements shall be differential
type with pressure ranges appropriate for intended service. One element
shall measure the variable while the other element measures the standard
reference. Static pressure controllers shall have slack diaphragms with
standard ranges between 0 to 1494 Pa 0 to 6 inches water gage and an
adjustable throttling range of 5 to 125 Pa 0.02 to 0.5 inch water gage.
Sensing element shall be mountable in ductwork and shall measure static
pressure without pulsations.
2.13.6
Pneumatic Differential Pressure Controllers for Liquid Applications
Differential pressure controllers shall have a minimum range of 0 to 345
kPa (gage) or 0 to 1724 kPa (gage) 0 to 50 psig or 0 to 250 psig as
specified or required for the application and shall have an adjustable
throttling range of 7 to 172 kPa (gage) 1 to 25 psig. Sensing element
shall be filled diaphragm type with three-valve manifold for isolation and
nulling. Provide syphons and pressure snubbers.
2.14
CONTROL DEVICES AND ACCESSORIES
Provide control devices and accessories.
2.14.1
Function Modules
Function modules shall accept mA dc analog input signals to produce analog
output signals or contact output signals. Modules shall have zero and span
adjustments for analog outputs, and setpoint adjustments for contact
outputs.
2.14.1.1
Minimum Position Switches and Temperature Setpoint Devices
Minimum position switches and temperature setpoint devices shall accept
manual input and shall produce steady analog output. Switches and devices
shall be suitable for recessed wall mounting or panel mounting and shall
have a graduated dial.
2.14.1.2
Signal Inverter Modules
Signal inverter modules shall accept analog input signal and produce analog
output signal that linearly reverses the direction of signal change of
input versus output.
2.14.1.3
High-Low Signal Selector Modules
High-low signal selector modules shall accept analog input signals and
select either the highest or the lowest input signal as the output signal.
2.14.1.4
Sequencer Modules
Sequencer modules shall provide fixed time delayed sequencing of one or
more contact transfers from an analog input signal. Sequencers shall
return contacts to their zero input signal condition when power is
interrupted.
SECTION 15901N
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