API MPMS 5.4:2005 pdf download

API MPMS 5.4:2005 pdf download.Manual of Petroleum Measurement Standards Chapter 5—Metering Section 4—Accessory Equipment for Liquid Meters.
5.4.6.1 ADJUSTER (CALIBRATOR)
A mechanical meter adjuster, or calibrator, changes the drive-system gear ratio between the volume-sensing portion of the meter and the primary register. The calibrator adjusts the register so that it is direct reading (that is, it provides a unity meter factor). For example, if precisely 100.0 units of volume are delivered by a meter, the register should he adjusted to indicate 100.0 units. Adjusters may he gear changing, friction driven, or clutch driven; depending on the design, the adjustment range may cover from I to 10 percent of throughput.
Different types of adjusters are capable of handling different torque loads. Friction-driven and clutch-driven adjusters show decreased sensitivity and repeatability when torque is increased. Increased torque reduces life in all types of adjusters. If adjustment to a unity meter factor is not required, the adjusting device should be omitted from the meter, and a direct drive shaft to the register should be installed.
5.4.6.2 REGISTER
A shaft-driven primary register is attached directly to the meter. The primary register displays the selected standard units of measurement, such as gallons, barrels, or cubic meters; the register also displays fractions of these units, if required. A primary register may be a totalizer only or a totalizer with a separate non-resettable register. A prirnaiy register is usually secured and sealed to the meter to prevent tampering (see 5.4.13).
5.4.6.3 PRINTER
A shaft-driven primary printer may accompany a primary register. The primary printer records on a measurement ticket the amount of liquid that is delivered. The ticket is printed in standard units of measurement, such as gallons, barrels, or cubic meters, and in decimal fractions of these units, if required.
Impact or pressure-roller printers are capable of printing one or more paper copies. The number of copies is limited by the type of paper and the clarity that is required. Mechanical printers usually show the lowest digit to the nearest whole number. Ticket forms are inserted, printed, and removed manually.
5.4.6.4 TEMPERATURE COMPENSATOR
A temperature compensator is a variable-ratio mechanism located in the meter’s drive train. It has a temperature sensor that works with the variable-ratio mechanism to correct the indicated volume to standard reference temperature, 60°F, 15°C, or 20°C. The temperature compensator must be set for the appropriate thermal coefficient ot expansion of the liquid hydrocarbon that is measured.
The location of the temperature compensator in relation to primary or other accessory readout devices depends on which of the devices arc to be compensated and which are to remain uncompensated. Where practical, mechanical temperature compensators should he avoided. Temperature compensation is bcst achieved by approved electronic methods within the flow computer.
5.4.6.5 PULSE GENERATOR
A pulse generator provides pulses in a quantity that is directly proportional to meter throughput. Pulsing devices can have various types of output signal, including switch closures, square-wave signals, and sine-wave signals. The devices can also have various frequency outputs.
5.4.6.6 REMOTE TRANSMISSION
A remote-transmission device is used to transmit a measurement signal to a remote device, such as a driving device, that in turn can operate most meter shaft-driven accessories.
5.4.6.7 PRESET DEVICE
A preset device can be preset for any quantity of meter throughput. At the pre-selected quantity, the device will stop the flow of liquid or will perform other, desired functions automatically, it may or may not be an indicating device.
5.4.6.8 GEAR-CHANGE ADAPTER
A gear-change adapter changes the output shaft speed by a fixed ratio and is sometimes used to achieve a given output for accessory devices.
5.4.6.9 RIGID EXTENSION
A rigid extension is a convenience device used to elevate meter accessories some distance above the meter itself.