GENERAL
Q - Where can I download the Apps?
A - The Apple App Store for iPhone and iPad
VIBRATION
Q - Why is API-617 referenced [In the Machinery Vibration Guide] for Centrifugal Compressors while all other machine classes reference ISO standards.
A - Reflects industry practice. API 617 is the preferred standard for Centrifugal Compressors and is the most widely referenced for these machines. References to the ISO standards are much more common for other machine classes and accelerometer based measurements.
BALANCE
Q - Rotor zone offers an option of phase lagging or phase leading in the balancing programs. What is this and how do I know which one my instrument is using?
A - Absolute phase can either be measured forward (leading) or backwards (lagging) from the speed reference. Different devices and manufacturers use different systems. Because rotor.zone is manufacturer independent we offer both choices. In the vast majority of devices absolute phase is always lagging which is why the rotor.zone balancing tools always set lagging as the default option.
Q - Other than the trial weight selector the rotorzone balancing tools don’t show any units for weight or vibration. What units are being used?
A - In the rotor.zone balancing tools what you put in is what you get out. All units entered will be the output units with regard to vibration and mass units (i.e if the Trial Weight is in Grams the output displayed on the chart will be in Grams also). Select an appropriate measurement unit based on the available transducers, the bearing type and machine speed. Note that the balancing calculator weight output is always displayed as an integer (whole number).
Q - The rotor zone graphical balancing tools show the correction weight being placed half way down the blade. Is this the correct position?
A - No, the display for both the rotor.zone graphical balance tools is a vector plot not a literal representation of the machine. All weights (trial and correction) must be placed at the same radius.
Q - Is the Graphical Phase Balance available for the iPhone
A - Graphical Phase balance is only listed as available on the iPad due to screen size requirements. It can be downloaded and used on the IPhone but this is not recommended as the small screen size on the phone makes it difficult to use.
FLUID MACHINERY
Q - Why does the pipe size utility make the pipes so big? my (book) tables are always one size smaller.
A - Sizing is based on 7f/s velocity for optimal efficiency. In the past (when energy was cheaper) a figure of 10f/s was commonplace.
Q - Why are imperial units shown as US?
A - Typically this system is used in North America and flow units are specifically in US Gallons rather than imperial gallons.
