Mechanical and chemical engineers have had to grapple with the changes made to measuring pressure. Today’s electronic pressure transmitters can be integrated into a complete control system, and they also can measure flow and temperature. Differential pressure transmitters are used to measure flow, and some pressure transmitters have temperature sensors on board to measure temperature. In some cases, this temperature measurement is used along with a pressure and volumetric flow measurement to compute mass flow.
Jesse Yoder, Ph.D. and president of Flow Research, says in a research report, “World Market for Pressure Transmitters, 2nd Edition,” that the pressure transmitter market “has grown substantially in the past five years, and in 2007, its worldwide value exceeded two billion dollars.”
Rick Gorskie, Honeywell senior product marketing manager, says one of the latest trends in pressure instrumentation is “the need for more self-diagnostics. Most plants unfortunately run their instrumentation to fail, which is a terribly inefficient way to operate. With selfdiagnostics, a pressure transmitter can alert operators to potential problems before they fail. This saves money because it’s usually three to five times more expensive to clean up the mess when a transmitter fails completely.”
Yoder adds, “Along with these improvements, suppliers are offering a wider variety of communication protocols, including Foundation Fieldbus and Profibus, however, HART is still the most popular communication protocol for pressure transmitters.”
ST 3000 pressure transmitter supports HART 6, making start-up and commissioning easier when used with Experion Process Knowledge System (PKS). HART 6 protocol makes for a less complex control system and tighter integration between control strategies and their associated field instruments. The ST 3000 series includes differential pressure, absolute pressure, gauge pressure, high-temperature gauge, flange-mount and in-line gauge pressure transmitters. Each provides pressure, level and flow measurements in applications ranging from hydrostatic tank gauging to measurement in boilers, fuel feeds and high-pressure reaction vessels.
PREVENT OVERFLOW OF TANKS
The series 45 pressure sensor with digital instrumentation is designed for tank level control and indication. The remote digital readout lends itself to installation in flange outputs on storage tanks. Beside storage tanks, the pressure sensor is suited for handling raw sewage, paper stock, oil, water and chemicals. Available with 2-in. through 12-in. flange mounting, the pressure sensor can be battery-, loop- or voltagepowered with a digital input for your PLC, computer or system controller.
Emerson Process Management
Rosemount 3051S wireless series offers integrated pressure, flow and level solutions for a variety of applications. Built on the SuperModule platform, it delivers stability for improved productivity.
Line of nuclear-qualified gauge, differential and absolute pressure transmitters are designed for use in the nuclear power generation industry. Models are available for inside containment, outside containment, radiation resistance and seismic, as well as “commercial grade” balance-of-plant (BOP) applications. The qualifications are to IEEE-344 (seismic) and IEEE-323 (environmental) standards. The transmitters feature a variety of performance and accident specification profiles that meet specific environmental/qualification requirements of PWR, BWR and CANDU power stations.
PROGRAMMABLE PRESSURE SENSOR
Programmable-output, high-accuracy pressure sensor allows the user to select the output as either two switch points or a 4-20 mA analog output with one switch point. The switch points are PNP/NPN-programmable and provide flexibility for applications where the output requirements are unclear.
HANDLES CORROSIVE MEDIA
Barcon PPC pressure transmitter with a ceramic sensing face is a no-fluid-fill- dry sensor that can be used with corrosive and abrasive media and can be ordered for sanitary applications with 3A mark. It offers continuous measurement of a range of process pressures for gases, vapors and liquids. Intrinsically safe models allow the installation in explosive areas with certifications to CSA, FM and ATEX standards. A number of electrical connections are available including fieldbus protocols such as PROFIBUS PA or HART.
LIQUID LEVEL/PRESSURE TRANSMITTERS
Automation Products Group
PT-500 submersible level/pressure transmitters have a vented, water-tight cable and a 4-20 mA output while submerged up to 450 ft. A removable stainless steel cage connects to the sensor with a snap ring and enables users to save on sensor replacement costs. Rugged IP68-protected PT-500 transmitters offer 0.50% accuracy of span and are temperature compensated for long-term stability. Typical applications are in sewage lift stations, tank-liquid-level measurement, water and wastewater, well-depth measurement and environmental waterdepth measurement.
The SRPM Secure-Sense pressure monitor watches the positive and negative pressure in protected environments and airborne-infection isolation per CDC guidelines. Accuracy is 0.001 in. of water column resolution. An RGB backlit touch screen display allows fingertip access to menus that guide the user through room setup, application, security and calibration. The SPRM has a green LED to indicate normal conditions and a red LED, audible alarm and SPDT relay for remote annunciation, to signal unsatisfactory room pressure status.
HAZARDOUS DUTY SWITCHES
BETA line of pressure and temperature switches has received FM and CSA approval. They have also received approval for use in hazardous locations, rated Class 1, Div. 1 explosion-proof standards. The switches are housed in a powder-coated or 316 SS enclosure for applications such as offshore oil platforms. They have over-range protection of up to 2000 psi/139 bar.
PRESSURE CALIBRATION KIT
DPG4000-KIT includes the DPG4000 digital gauge with a back-lit, 5-digit display with 16.5-mm high digits and 20-segment bargraph; a SS case that meets NEMA 4 (IP65) rating; a pneumatic or hydraulic hand pump; and a selection of fittings and hoses. A pneumatic pump is included in kits with ranges of 500 psi or below, which are capable of generating 0 psi to 500 psi pressure or 0 in. to 28 in. of mercury vacuum. A hydraulic pump is included with kits for ranges of 1000 psi or higher. Accuracy is +/-0.05% FS.
PTU300 barometric pressure, relative humidity and temperature transmitter has digital measuring electronics for all three parameters, several small RH&T sensor heads for different applications and calculated humidity variables. The backlit display shows three-hour graphical trends and up to one year of historical data. The recorded measurement data can be viewed on the display or transferred to a PC. Seven language options are available.
Meriam Adalet Wireless
AWI-PS fully integrated, self-contained wireless pressure switch monitors pressure in industrial applications. Available in battery- or AC-powered versions, it includes the wireless transmitter, pressure switch and self-contained power source, all in one aluminum enclosure. It provides tank farms, pipelines, in-plant and other industrial applications with pressure monitoring and measurement without the constraints of hard wiring. The bellows pressure-sensing elements in the pressure switch device are constructed from 316 SS and offer adjustable pressure ranges from 0 psi to 5000 psi.
Chandler Engineering, A Unit OF Ametek
Quizix pumping systems offer continuous pulse-free flow or pressure control at high pressures and temperatures required to optimize critical fluid delivery and extraction applications such as catalyst injection, chromatography and core testing. They deliver or receive at a constant pressure or flow rate from sub-nano liters/minute to 400 ml/minute at pressures up to 20,000 psi. All can be controlled via PumpWorks software that provides complete control over all pump functions.
UNDER THE SEA
SST Series pressure and temperature transmitters for subsea oil and gas applications operate to depths of 5000 ft. A new SST510 DP boasts a 10,000-psi working pressure. They have fully
welded duplex stainless steel construction and a dual compartment design with a glass-to-metal seal that provides secondary containment and facilitates oil-filled harness termination.