API MPMS 5.4:2005 pdf download.Manual of Petroleum Measurement Standards Chapter 5- -Metering Section 4- Accessory Equipment for Liquid Meters.
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 lactor). For example. if precisely 100.0 units of volume are delivered by a meter. the register should be adjusted to indicate 1(X)A) units. Adjusters may be 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 no 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 sLandard units of measurement, such as gallons. barrels, or cubic meters: the register also displays fractions of these units. if required. A primary register may he a total i/cr only or a totaliicr with a separate non-rcsctiablc register. A primary register is usually secured and scaled 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. Thc 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 rcquired. Mechanical printers usually show the lowest digit to the nearest whole number. Ticket Ibrms arc inscrted. printed, and removed manually.
5.4.6.4 TEMPERATU RE 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, (0”F. I 5”C. or 20°C. The temperature compensator must be set for the appropriate thermal coefficient 01’ expansion of the liquid hydrocarbon that is measured.
API MPMS 5.4:2005 pdf download
