The Chinese and Asian Art Forum. For Fans, Collectors and Dealers.
Basic Rules For the BidAmount Asian Art Forum: Talk about whatever you want. You can even discuss and offer things that are for sale if they are authentic. Maximum image file size per post is 2 MB. Images of 700pxl x 700pxl are optimal if saved at a medium resolution. Be respectful of others and enjoy yourself. Click the YouTube link for a brief tutorial on using the forum. You can also EMBED Videos by cutting and pasting from You-Tube, Vimeo etc.
NOTE: To post an item or add a new post, click open the category title from the FORUM LIST, and CLICK the Blue ADD TOPIC button.
About Me
Pressure Transmitter
Pressure
transmitters are a common and well understood technology especially within the
petroleum, petrochemical, refrigeration and fuel gas markets and they are extremely
economical compared to other technologies.
Pressure transmitters are a common and well understood technology especially
within the petroleum, petrochemical, refrigeration and fuel gas markets and they are
extremely economical compared to other technologies. If a level is to be made in an open
vessel a pressure transmitter (PT) is placed at the bottom and the head pressure caused by
the weight of the liquid can be used to calculate the height of the liquid. Differential
pressure transmitters can be used on pressurised vessels using the same principles (9).
Level measurement using pressure transmitters cannot be deployed in primary separators
as the change in temperature will impact the measurement, the change in density of the oil
during operation will impact the measurement and any fluctuation of the
oil/gas differential pressure control valve or pressure disturbances would also
impact on the reading.
Portable dP gauges are used to monitor the dP across strainers, online densitometers,
DB&B valves, prover interchange valves, and other devices. All pressure gauges shall be
equipped with calibration stickers indicating the last test or calibration date and who
performed the calibration. The calibration sticker should be clearly visible and
constructed of a rugged material. All recordings on the sticker should be made with
indelible ink. The dial gauge cover should be clear and abrasive resistant. The
pressure gauge should be readable with permanent figures and markings and equipped with a
blowout disc for safety. The scale shall be in graduations of no greater than 2 psig with
longer graduations at each 5 psig and numbered at not greater than 10 psig intervals. The
error at any point on the scale should not exceed ±2 psig. The maximum
allowable working pressure (MAWP) of the dP gauge should be at least equal to the MAWP
for the measurement facility.
A <a href="http://www.onlysft.com/pressure-transmitter/differential-pressure-
transmitter/" target="_self">differential pressure transmitter is a device that
translates physical force to an electrical signal. The most common type of force transducer
uses a diaphragm, piston, bourdon tube, or bellows to sense the physical force and various
strain/force-sensing devices to convert the deflection of the physical element to an
electrical signal. Traditional strain-sensing devices include the following: capacitive
cells, piezoresistive strain gauges, piezoelectric quartz material, and electromagnetic
devices.
In the United States, companies such as Rosemount, Cameron/Barton, Foxboro, and
Ultrasystems have provided transmitters that specialize in safety system pressure
measurements. These transmitters may still function successfully on some iPWR designs, but
many will have to be reengineered for different mounting configurations, size constraints,
and environments. Many iPWR designers, when faced with a modification program, may choose
to go with new technologies rather than modifying the old ones. The new technologies may
offer advantages in size, redundancy, accuracy, and environmental resilience. Some of these
new technologies include microelectromechanical system (MEMS) sensors, fiber optic sensors,
and ultrasonic sensors.
In the optical fiber category, a company called Luna Innovations has developed and
successfully tested fiber optic pressure sensors, like the one shown in Fig. 6.1, in a
research reactor environment. These fiber optic pressure sensors have been shown to operate
in radiation environments with flux levels much higher than those compatible with most
electronic pressure sensors. With traditional technology, it is necessary to protect
traditional electronic <a href="http://www.onlysft.com/pressure-transmitter/gauge-
pressure-transmitter/" target="_self">gauge pressure transmitter from harsh radiation
conditions near the core; this requires the use of long pressure sensing lines, which limit
the response time to pressure transients and increase the number of wall penetrations. Luna
’s fiber optic pressure sensors are designed to operate in harsh environments. When these
pressure sensors were combined with Etalon-based fiber optic temperature sensors providing
temperature compensation, drift effects were minimized. The attractiveness of this
technology for iPWRs is obvious, with the elimination of sensing lines, the minimization of
penetrations, the small size of the sensor, the rapid response to pressure fluctuations,
and the operability in high radiation fields. With these attributes, this technology bears
merit for primary and secondary side pressure measurement (Dickerson et al., 2009).
Pressure or DPT transmitters have been used to measure liquid levels of open
or pressurized tanks, respectively, with proper calibration taking care of the density
value of the subject liquid. These types are used for level measurements of boiler drums,
all heaters, deaerators, condenser hotwells, condenser surge tanks, and all
dosing tanks.
For open tanks, a pressure tapping at a suitable location is connected through the
impulse line, to the high-pressure port of the DPT with the low-pressure port open to
atmosphere. The pressure (or DP) sensed by the DPT is proportional to the level with a
known liquid density (ρ) and force due to (earth’s) gravity (g). With proper calibration,
the potential transform can now be used as a level transmitter.
Regarding the pressurized tank or vessel, single-pressure tapping does not
serve this purpose as it senses the pressure of the vessel and the pressure of the liquid
level. To balance out the vessel pressure, another pressure tapping for sensing it is
connected, through the impulse line, to the low-pressure port of a DPT so that the output
will only be proportional to the liquid level only with known ρ and g.
Another new technology for pressure sensing is the polymer-derived ceramic MEMS sensor.
At the forefront of this technology, a company, Sporian Microsystems, has developed a
pressure/temperature sensor made to survive high temperatures (Fig. 6.2). This technology
offers a solution for pressure sensing in iPWRs due to its hardy environment survivability
and its small size. The small size allows for the installation of redundant units and the
measurement of pressure at many points, possibly with fewer penetrations than traditional
sensors.
These new technologies have attributes like small size, heat
survivability, radiation hardness, fast response, and low maintenance. These attributes are
highly valued in iPWR designs for obvious reasons.
The Series-211 differential <a
href="http://www.onlysft.com/pressure-transmitter/absolute-pressure-transmitter/"
target="_self">absolute pressure transmitter can accurately measure positive,
negative or differential pressure and send the corresponding 4–20 mA output signal to
a recording system. It is not position sensitive and can be mounted in any orientation
without compromising accuracy. It also features a power LED, so one always knows when the
transmitter is operating. The compact, light-weight design makes installation simple and
easy. Two inlets for the pressure connections are located on the front of the unit, labeled
“High” and “Low”. For differential pressure measurement, the higher pressure should be
connected to the “High” pressure port. For positive pressure, the “Low” pressure port
should be left vented to atmospheric pressure. Periodically, it is necessary to recalibrate
the gauge to maintain the accuracy. For “zero” gauge, the pressure connection needs to be
removed from both pressure ports and to adjust the zero potentiometer until the output is
4 mA. To span the gauge, the full scale pressure to be applied to “High” pressure
port and to adjust the span potentiometer until the output is 20 mA. The salient
features of the pressure transmitter are compact design, LED power indication, 2-wire
design, 4–20 mA output, ± 0.25% accuracy level, 0–90 mmHg pressure range, –
25 °C to 70 °C operating temperature ranges, 2-wire output signal and 12–30
VDC power supply.
Drum level is measured by differential <a
href="http://www.onlysft.com/temperature-transmitter/thermal-resistance-temperature-
transmitter/" target="_self">thermowell temperature transmitter installed in line with
Figures XII/3.5-1(a,b). Note that for drum-level measurement a temperature-equalizing
column has been used to ensure that in both limbs of DPTs temperatures are equal, meaning
that the densities are equal. So far, the discussion has been about installation and making
the two limbs’ temperatures equal. Now level is measured by because there is an incumbent
pressure P1 at the top, which needs to be subtracted to get the level. So,
finally, one is left with P1 at the top and P1 + pressure due to water
head (P) on the other limb. Therefore DP = pressure due to water head, P = h
× ρ × g.
For a particular place, g is always constant. So water
head P varies with h (level) and density, which in turn depends on
temperature. In the drum, incumbent pressure is due to saturated steam pressure, and for
saturated steam for each pressure there is a particular temperature.
Therefore, saturation pressure is chosen to compensate/correct the density
effect. Temperature is a sluggish parameter, so pressure is chosen to compensate.
Degradation of the transmitter’s accuracy and response time (two
uncorrelated phenomena) are the two most important consequences of ageing. Ageing caused by
heat and humidity can cause the transmitter sealing materials to fail, allowing moisture to
enter the transmitter housing. This can cause calibration shifts and high-frequency noise
at the transmitter’s output, which can render the transmitter inoperable or unreliable.
Though NPP I&C failure data indicates that calibration drift accounts for anywhere from
59% to 77% of all age-related failure in pressure transmitters (fow blockage, fatigue, and
other factors accounting for the remaining age-related failures), a survey of the nuclear
industry in the early 1990s showed that fewer than 10% of NPP pressure transmitters
actually drift out of tolerance and that in a typical two-year fuel cycle only about 1–3%
of transmitters suffer calibration failure.
The analog signal operates over a 4–20 mA range (0 to 5 Vdc
with a 250 Ω high-precision pull-up resistor). For proper analog signal discrimination,
the tertiary device should be equipped with at least a 12-bit ADC converter. Digital
signals are preferred over analog signals for accuracy. However, the tertiary device must
be able to communicate with the secondary devices using a common communications protocol.
The status signals typically are used for indicating block valve status (fully
open, fully closed, in travel), generating commands to obtain a sample (activation of
sample extractor), and alarm status.
The transmitters should be equipped with a display of the current
readings at the transmitter housing in appropriate engineering units. The transmitters
should be equipped with both analog and digital output to the tertiary device.
For analog communications to the tertiary device, a 4–20 mA
signal is preferred and requires a high-precision 250 Ω pull-up resistor (to convert from
0 to 5 Vdc). The dampening parameters should be turned off or set to its lower limit. For
digital communications to the tertiary device, the update interval of the transmitter
should be less than or equal to 1 second. The transmitters should be equipped with an
appropriate communications protocol and the dampening parameters should be turned off or
set to its lower limit.
The sensing lines that bring the pressure signals from the process to
the transmitter can become partially or totally blocked due to sludge, boron solidification
(PWRs), and other debris in the reactor coolant, causing sluggish dynamic performance in
the transmitter. According to NRC data, blockages, voids, and leaks account for nearly 70%
of the age-related problems in sensing lines. Nevertheless, the effects of ageing on
response time are even less significant than the effects on calibration. The response times
of 84% of transmitters tested in a 1994 study written by the author for Nuclear safety were
unaffected by ageing. Of the remainder, only 4% delivered response times that could be
considered failing.
Occupation
Thanks for visiting "The BidAmount Asian Art Forum | Chinese Art"
If you sell on eBay, or have a shop feel free to post images and descriptions and links.
Check back often for discussion about the latest news in the Chinese art and antique world. Also find out about the latest Asian art auctions at Sotheby's, Christie's, Bonhams and Tajans.
Auction results for: fine porcelain, ceramics, bronze, jade, textiles and scholar's objects. As well as Japanese, Thai, Vietnamese and other Asian cultures.
Thank you,
Peter Combs
Topics and categories on The BidAmount Asian Art Forum | Chinese Art
Kangxi vases, Kangxi dishes and chargers, Kangxi ritual pieces, Kangxi scholar's objects, Qianlong famille rose, Qianlong enamels, Qianlong period paintings, Qianlong Emporer's court, Fine porcelain of the Yongzheng period. Chinese imperial art, Ming porcelain including Jiajing, Wanli, Xuande, Chenghua as well as Ming jades and bronzes.
Join the BidAmount Chinese and Asian art discussion board and forum today
The BidAmount Asian Art Forum | Chinese Art
A free Asian art discussion board and Asian art message board for dealers and collectors of art and antiques from China, Japan, Korea, Thailand, Cambodia, Vietnam and the rest of Asia. Linked to all of the BidAmount Asian art reference areas, with videos from plcombs Asian Art and Bidamount on YouTube. Sign up also for the weekly BidAmount newsletter and catalogs of active eBay listing of Chinese porcelain, bronze, jades, robes, and paintings.
The art of calligraphy - and for the ancient Chinese it certainly was an art - aimed to demonstrate superior control and skill using brush and ink. Calligraphy established itself as one of the major Chinese art forms during the Han dynasty (206 BCE - 220 CE), and for two millennia after, all educated men were expected to be proficient at it.
The Museum’s collections of Asian art span nearly five millennia and encompass the cultures of China, the Himalayas, India, Japan, Korea, and Southeast Asia. In 2007, the Museum launched an initiative to create dedicated galleries for the collection, beginning with a gallery for the arts of Korea ...
Chinese art is full of symbolism, in that artists typically seek to depict some aspect of a totality of which they are intuitively aware.
China Online Museum is the finest online museum of Chinese art. It features Chinese calligraphy, painting, ceramics, bronzes, carving, and other artworks.
Chinese Ceramics & Works of Art. Overview Upcoming auctions Contacts Auction results ... Christie’s sales of Chinese ceramics and works of art showcase centuries of Chinese history. Held throughout the year in London, New York, Paris and Hong Kong, they attract a wide audience of collectors and connoisseurs vying for pieces as diverse as ...
Explore Asian Art Week. Contact the Specialist Department. Chinese Paintings ... Senior Specialist, Head of Sale. ehammer@christies.com. Tel:+1 212 641 5760. Bid in-person or online for the upcoming auction:Fine Chinese Paintings on 10 September 2019 at New York. Bid in-person or online for the upcoming auction:Fine Chinese Paintings on 10 ...
Discover an abundance of must-see art from all corners of a vast continent at Christie’s NY Asian Art Week. From contemporary classical and Chinese paintings to works with exemplary provenance from the Art Institute of Chicago, our Rockefeller Paza galleries will be full of ancient treasures and contemporary masterworks in a salute to the vibrant arts of Asia.
Sold to benefit The Art Institute of Chicago’s Asian Art Acquisition Fund, the sale features 84 lots with a focus on Ming and Qing porcelains, and offers a rare insight into the taste for collecting Chinese ceramics and works of art in the Midwest from the end of the 19th century through the 1980s. Highlights include two Wanli wucai garlic-head vases, a Qianlong mark and period, blue and ...
Specialist, Chinese Paintings, Christie's London Dr Malcolm McNeill is a Specialist in Chinese Paintings at Christie’s, based in London. He previously worked as an assistant curator of the Chinese collections and the Victoria and Albert Museum in London, as a researcher at the British Museum, and as a translator and tour guide at the National Palace Museum in Taipei.
The Christie's Education 2020 Conference: The Chinese Art Market 18 Jun 2019 Christie’s Education is delighted to announce our first international academic conference in Asia which will take place in Hong Kong from 26-27 November 2020 at the Hong Kong Convention and Exhibition Centre and will run in parallel with Christie’s Hong Kong Autumn Auctions.
The summer Chinese Art sale in Hong Kong will feature works of art from several private collections, including Qing porcelains and textile from the collection of the legendary Chinese art dealer A. W. Bahr (1877–1959), fine gilt bronze Buddhist sculptures from an old Hong Kong collection, an East Asian collection of Qing dynasty wine cups and jades, and a Japanese collection of Song ceramics ...
Sotheby's Chinese Works of Art Department holds two auctions each year in London, New York, Hong Kong and Paris.
Chinese Art - View Auction details, bid, buy and collect the various artworks at Sothebys Art Auction House.
With more than 340 Chinese works of art dating from the Neolithic to the Republic periods, highlights of this sale include a selection of Qing Imperial monochromes from the collection of Arnold and Blema Steinberg, early ceramics from the Art Institute of Chicago and Chinese porcelain and works of art from the collection of Henry Arnhold.
Results: Sotheby's Asia Week achieved $52.4 million in six strong auctions, exceeding pre-sale estimates. With 76.5% of lots sold and 60.3% of lots surpassing high estimates, the Asian art sales at Sotheby's indicate continued collector interest in the finest works of art from China, India and and the Himalayas.
Today's sale of Important Chinese Art will proceed as planned with sessions at 10 AM and 2 PM EDT. Sotheby's will be monitoring the weather conditions throughout the day and will be available to coordinate alternative bidding options should conditions make it difficult for clients to attend the auction in person.
Bonhams Chinese Art department is renowned for offering the finest works of art representing the richness and breadth of China's artistic heritage, particularly Imperial porcelain, white and spinach green jades, cloisonné and Buddhist art. Specialised international auctions are held globally, including London, Hong Kong and San Francisco.
Bonhams : Chinese Works of Art We use cookies to remember choices you make on functionality and personal features to enhance your experience to our site. By continuing to use our site you consent to the use of cookies. Please refer to our privacy and cookie policies for more information.
Bonhams Fine Art Auctioneers & Valuers: auctioneers of art, pictures, collectables and motor cars. We use cookies to remember choices you make on functionality and personal features to enhance your experience to our site. By continuing to use our site you consent to the use of cookies. ... Chinese Art (US) General enquiries
Bonhams : Fine Chinese Art We use cookies to remember choices you make on functionality and personal features to enhance your experience to our site. By continuing to use our site you consent to the use of cookies. Please refer to our privacy and cookie policies for more information.
Bonhams Fine Art Auctioneers & Valuers: auctioneers of art, pictures, collectables and motor cars Bonhams : Asian Art We use cookies to remember choices you make on functionality and personal features to enhance your experience to our site.
Bonhams are international auctioneers of fine Chinese and Japanese art. We specialise in rare Imperial and Export Chinese ceramics and works of art, as well as Japanese ceramics, fine and decorative works of art from the Neolithic Period to the 20th century. View on map
Bonhams Fine Art Auctioneers & Valuers: auctioneers of art, pictures, collectables and motor cars. We use cookies to remember choices you make on functionality and personal features to enhance your experience to our site. By continuing to use our site you consent to the use of cookies. ... Asian Art Bonhams. Work. 22 Queen St.