Flow Control - Jan 2012
supplier of variable area meters The company offers both lowflow and high flow glass tube meters The company quotes 2 percent 3 percent and 10 percent accuracy for its high flow glass tube meters depending on the model It quotes accuracies of 5 percent and 10 percent on the low flow glass tube meters Brooks has a line of armored metal tube VA meters called the MT Series These meters have corrosion resistant options for metering aggressive fluids Transmitters with 4 20mA and HART are offered as options for remote monitoring Blue White Industries bluwhite com offers primarily acrylic and polysulfone VA meters Polysulfone is a type of plastic that is tolerant of high temperatures The company offers both tube and block models The block type meters are rectangular instead of round and are designed for panel mounting Blue White quotes flowrates of 025 to 100 gallons per minute GPM on some of its machined acrylic meters The largest line size of these meters is 2 inches Where They Stand Variable area flowmeters are considered to be traditional technology meters They are the least expensive and least sophisticated of the traditional meters They are relatively simple in construction when compared to a turbine or positive displacement meter Yet variable area meters have maintained their market size over the years even though this size is less than that of turbine or positive displacement meters One reason why VA meters have maintained their presence in the market is that suppliers have offered improvements such as transmitter outputs and have built VA meters designed for specific applications This often means choosing particular materials of construction along with a different shaped tube or float This increases the versatility of VA meters and makes them more appealing to end users with specific needs Another reason for their growth is that they fill a genuine need in the market In some cases end users simply need a flow no flow indication or they are satisfied with 2 percent or 5 percent accuracy Variable area meters may also do well in regions where cost is a major consideration and high accuracy is not always required Depending on application VA meters may do well in China India Australia Malaysia and Indonesia KROHNE is positioned to supply these regions with its variable area manufacturing facility in Chengde China Another major VA supplier positioned to sell into the Asian region is Tokyo Keiso tokyokeiso co jp of Japan Variable area meters have a fascinating past and they could have a bright future How bright their future will be depends on how much research and development suppliers decide to put into them By incorporating more advanced features such as transmitter outputs more varied materials of construction different float designs and more industry approvals VA suppliers can potentially position themselves for expansion At the moment much research and development money is going into Coriolis and ultrasonic meters That is not likely to change but if VA suppliers can continue to improve their products and develop higher accuracies the variable area flowmeter market has a chance to expand FC Jesse Yoder Ph D is president of Flow Research Inc in Wakefield Mass a company he founded in 1998 He has 24 years of experience as an analyst and writer in process control Dr Yoder specializes in flowmeters and other field devices including pressure and temperature products He has written over 150 journal articles on instrumentation topics Dr Yoder can be reached at jesse@ flowresearch com www flowresearch com For more information on Flow Researchs research in the area of variable are flow measurement see FlowVA com Circle 20 or Request Info Instantly at www FlowControlNetwork com www FlowControlNetwork com January 2012 29
You must have JavaScript enabled to view digital editions.
