Chapter 3 And 4 Flashcards
A special kind of head pressure measuring method allowing the measurement of head pressure in a liquid without the pressure sensor coming in contact with the process fluid
Blubber
Monitors all level points in a tank from the zero percent level (bottom of the measuring device) to 100% full.
Continous level measurement
A distance from the surface of a liquid that extends downward
Depth
Measures the process variable directly in terms of itself ( e.g a sight glass or dipstick).
Direct level measurement
A sealed cyndrically shaped tube used to measure bouyancy
Displacer
There are three types of flat glass level gauges , reflex , transparent and welded pad. The heavy thick bodied glass promotes safety in high temperature and high pressure hydrocarbon service
Flat-glass level gauge
An instrument that used cables ,pulleys , levers or any other mechanism to convey the position of a float to a liquid level
Float gauge
A distance from zero reference point to the surface
Height
Liquid head pressure measurement expression;also expressed pounds per square inch (psi)
Inches of water column
Measures another process variable(e.g head pressure or weight) in order to infer level
Indirect level measurement
The measurement from the bottom of a tank to the surface of the product
Innage
A plane where two materials meet . Can be between two liquids , a liquid and a slurry , and or liquid and foam
Interface level
The act of establishing the height of a liquid surface in reference to zero point
Level measurement
The pressure exerted by the height of a column of liquid;the most common indirect level measurement.
Liquid (hydrostatic) head pressure
A device comprised of a strain gauge bonded to a robust support column called a force beam ; together these are capable of supporting the entire weight os a vessel and its contents ; a transducer that measures force or weight.
Load cell
The curved upper surface of a column of liquid having either a convex or concave shape
Meniscus
Uses a tightly controlled gamma radiation source with a detector to infer a level in a tank and used when other technologies are unsuccessful;located on the outside of a tank and impervious to the effects of adverse process conditions;commongamma radiation sources are the radioisotopes cobalt 60 and cesium 137
Nuclear device
A measurement of level based upon percentage with zero percent level at the bottom of the measuring device and 100% level being at the top
Percent level measurement
Level is measured at one distinct point in a tank
Point level measurement
Liquid head pressure measurement expression; also expressed as inches of water column
Pounds per square inch (Psi)
Has a single flat glass panel capable of refracting light off a prism like back side creating a silvery contrast above the liquid level that allows it to be seen from a distance
Reflex level gauge
A natrow strip of calibrated ribbon(steel) used to measure length
Tape gauge
Has two transparent flat glass panels,front and back, thqt form a vertical chamber in conjunction with the metal sides where the process level can be seen and measure using this vertical chamber.
Transparent level gauge
A reflex or clear glass tube open into a vessel on top and bottom
Tubular type sight glass
The measurement from the surface of the product to the top of the tank
Ullage(outage)
An accurate distance measuring instrument usually inserted at the top of the vessel; emmits a pulse of energy that is reflected off the surface of the material back to the receiver ; may be either a single unit (transponder) or two separate units ( transmitter aand receiver
Ultrasonic and radar device
Generally made of flat glass and integrally mounted to the vessel by either welded or flanged connection with threaded pipe; extremely rugged to prevent vessel drainout
Welded pad gauge
Most common types of level sensing and measurement devices in process industries
Gauge or sigthglass Float Tape gauge Differential pressure cell Bubbler Displacer Ultrasonic device Nuclear device Load cell
A trademark name for one manufacturer multiport tube having four impact points spaced across the pipe and facing the flow with another tube sensing static pressure measures the average pressure produced by the four impact points
Annubar tube
A magnetic flow meter designed to determine volumetric flow of electrically conductive liquids slurries and corrosive and or abrasive materials
Electromagnetic flow meter
Magmeter
Flow rate( an instantaneous flow measurement) and total flow (a summation of instantaneous flow rates over a time interval or an accumulation of counts provided by a positive displacement device)’measured in volume or mass u its respect to time
Flow measurement
Similar to a venture tube but has an extended tapered i let commonly installed in a short piece of pipe called a spool piece.
Flow nozzle
A measure of how much fluid moves through a pipe or channel with a given period of time
Flow rate
Flowing liquids and gases that mix easily because of the continual movement between molecules
Fluid
Measuring one variable of a process to infer another
Indirect flow measurement
Smooth flowing fluid
Laminar flow
The most common type of true mass flow meter;a meter that elimantes the need to compensate for typical process variations such as temperature , pressure,density,and even viscosity
Mass flow meter coriolis
A unit of measure for the weight being passed through the pipe to allowed pressures upstream and downstream of an orifice plateto be measure
Oriface flange
A piece of 1/8 to 1/12 inch thick metal with a calibrated hole drilled or cut through types of orifice plates include the concentric plate eccentric bore, and segmental plate
Orifice plate
A common way to indicate a flowing process with 100% equating to an actual quantity such as gallons per minute (gpm)
Percentage flow rate
An L shaped tube that is inserted into a pipe with its open end facing the tube and another tube sensing static pressure
Pilot tube
When flow is measured in absolute volumes where the flowing materials is admitted into a chamber known volume and the transferred to a discharge point ; a counter registers the number of times the chamber fills and discharges
Positive displacement flow measurement
Piston oval gear nutating disk and rotary vane types of positive displacement flow meters
Positive displacement meter
A mathematical computation describing the flow of fluids numerically
Reynolds number
A direct read variable area (tapered) flow tube where the fluid enters through the bottom then flows upward lifting a free floating indicator plummet (float) the position of the float references to the calibrated marks on the glass tube to indicate flow rate
Rotameter
A flow tube containing a free-spinning turbine (fan) wheel where the revolutions per minute (rpm) are proportional to flow rate ; the faster the flow the faster the turbine spins ;the output is fed directly into an instrument to indicate either flow rate or total flow
Turbine meter
Fluid flowing with turbulance
Turbulent flow
A primary element used in pipelines to create a differential pressure such that when converted to flow units (e.g.gpm) the flow in the line is measured
A unit of measure for the volume being passed through a certain location in a pipe or channel per unit ; usually measured in gallons per minute and cubic feet per minute
The most common types of flow sensing and measuring devices
Orifice plates Venturi tubes Flow nozzles Pilot tubes Annubar Rotameters Electromagnetic meter Turbine meters Mass flow meters
