1.01 THE REQUIREMENT
A. The Contractor shall furnish, test, install and place in satisfactory operation the pressure indicating transmitters, with all spare parts, accessories, and appurtenances as herein specified and as shown on the Drawings.
1.02 RELATED WORK SPECIFIED ELSEWHERE
A. Control and Information System Scope and General Requirements
B. Powered Instruments, General
PART 2 -- PRODUCTS
2.01 GAUGE PRESSURE INDICATING TRANSMITTERS
A. Gauge pressure transmitters shall be of the piezoresistive type with a process]isolated diaphragm with silicone oil fill, microprocessor]based "smart" electronics, and a field adjustable rangeablility of 20:1 input range. Span and zero shall be continuously adjustable externally over the entire range. Span and zero adjustments shall be capable of being disabled internally. Transmitters shall be NEMA 4X weatherproof and corrosion resistant construction with low]copper aluminum body and 316 stainless steel process wetted parts. Accuracy, including nonlinearity, hysteresis and repeatability errors shall be plus or minus 0.1 percent of calibrated span, zero based. The maximum zero elevation and maximum zero suppression shall be adjustable to anywhere within sensor limits. Output shall be linear isolated 4]20 milliamperes 24 VDC. Power supply shall be 24 VDC, two-wire design. Each transmitter shall be furnished with a 5]digit LCD indicator capable of displaying engineering units and/or milliamps and mounting hardware as required. Overload capacity shall be rated at a minimum of 25 MPa. Environmental limits shall be ]40 to 185 degrees Fahrenheit at 0]100% relative humidity. Each transmitter shall have a stainless steel tag with calibration data attached to body.
B. The piezoresistive silicon pressure sensor shall be mechanically, electrically, and thermally isolated from the process and the environment, shall include an integral temperature compensation sensor, and shall provide a digital signal to the transmitter's electronics for further processing. Factory set correction coefficients shall be stored in the sensor's non]volatile memory for correction and linearization of the sensor output in the electronics section. The electronics section shall correct the digital signal from the sensor and convert it into a 4]20 mA analog signal for transmission to receiving devices. The electronics section shall contain configuration parameters and diagnostic data in non]volatile EEPROM memory and shall be capable of communicating, via a digital signal superimposed on the 4]20 mA output signal, with a remote interface device. Output signal damping shall be provided, with an adjustable time constant of 0]36 seconds. Total Long Term Stability (Frequency of Calibration) shall be no less than 0.10% of URL for 1 year.
C. Where scheduled, gauge pressure indicating transmitters shall be calibrated in feet of liquid for liquid level service.
D. Gauge pressure indicating transmitters shall be Model 2088 as manufactured by Rosemount, or equal.
2.02 DIFFERENTIAL PRESSURE INDICATING TRANSMITTERS
A. Differential pressure indicating transmitters shall be the same as the gauge pressure transmitters except for body specifications. Differential pressure units shall be furnished with close coupled stainless steel three valve manifold assembly.
B. The electronics sections of differential pressure transmitters shall contain user]selectable square root extractors to provide a linear 4]20 mA DC output proportional to flow, when activated. Square root extractor circuitry shall be activated on the flow transmitters listed in the Instrument Schedules. In addition, each flow transmitter shall be furnished with laminated flow versus differential pressure curves wall mounted adjacent to the transmitter.
C. Differential pressure indicating transmitters shall be Model 2051CD as manufactured by Rosemount, or equal.
2.03 FLANGE MOUNTED LEVEL INDICATING TRANSMITTERS
A. Flange-mounted tank liquid level indicating transmitters shall be the same as gauge pressure transmitters except for body type.
B. The flange-mounted sensor shall consist of a special non-corrosive isolating diaphragm with fill fluid in a sealed capillary system to transmit liquid pressure to the sensing element. A second isolating diaphragm shall transmit pressure through the fill fluid to the sensing diaphragm in the center of the capacitance cell. An isolating diaphragm and fluid fill shall also be provided on the opposite side of the sensing diaphragm to convey atmospheric or reference pressure.
C. All mounting flanges, diaphragms, O-rings and materials used in construction shall be non-corroding, compatible with each other, and compatible with the liquid being measured.
D. Flange-mounted liquid level transmitters shall be as manufactured by Rosemount, Model 2051L.
PART 3 -- EXECUTION
3.01 REQUIREMENTS
A. Refer to the Specifications.
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