API MPMS 5.4:2005(2015) pdf download
API MPMS 5.4:2005(2015) 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 pnn ides a unity meter facior. For esample, if precisely 100.0 units of volume are delivered by a meter. the register should he adjusted to indicate 100.0 units, Adjusters may be gear changing. friction driven, or clutch driven: depending tin the design, the adjustment range may cover (turn I to It) percent of throughput.
[)itTerent types of adjusters are capable of handling differ’ ent torque loads. Friction-driven and clutch-driven adjusters show decreased sensitivity and repcatahility when torque is increased, Increased torque reducc. life in all types of adjusters. If adjustment to a unity meter (actor is not required, the adjusting device should he omitted from the meter. and a direct dnve shaft to the register should he installed.
5.4.6.2 REGISTER
A shaft-driscn 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 totaliier only or a totalizer with a separate non-resenable register. A primary register is usually secured and sealed to the meter to present tampering (sec 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 delivcrcd. 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 pecssurc-rolkr printers arc 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. flckci forms arc inserted, printed, and removed manually.
5.4.6.4 TEMPERATURE COMPENSATOR
A temperature compensator is a s’ariahle.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, 60E I 5CC. or 20°C. The temperature compensator must be set fur the appropriate thermal coefficient of espansion of the liquid hydrocarbon that is measured,
54.7.2 READOUT
An electrically dnsen ptirnaiy readout indicate. quantities in the desired standani units of mcasurcmcnt. such as gallons. barrels, cubic meters: it also indicates decimal fractions of these units, if required, The accuracy of the readout depends on system resolution, which is pniponional to the number of pulses per unit quantity.
Eketiumechankal registers are limited in speed. Their adequacy should therefore he considered hcfnie a decision is made about installation. Electronic readouts are not limited in speed. hut they depend on electrical power fur proper performance. l)wing a power fail. standby power is needed to venfy and retain meter registration if a mechanical means is not asailable.
5.4.7.3 PRINTER
.Several types of electrical printers are asailable, The two common wws include electrnniechanical mechanisms in the final stages. The first type is designed so that each adjacent digit advances the next digit into position as it would in a mechanical readout. This type of printer is simple, inexpensive. and widely used. hut it has limited speed and longevity.
