ASTM F998-2018 pdf free download

ASTM F998-2018 pdf free download.Standard Specification for Centrifugal Pump, Shipboard Use
1. Scope
1.1 This specification covers the requirements applicable to the design and construction of centrifugal pumps for shipboard application. The three classes of service covered by this specification are as follows: 1.1.1 Class 1—Freshwater, 1.1.2 Class 2—Seawater, and 1.1.3 Class 3—Hydrocarbon pumps (less than 1500 SSU). 1.2 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard. 1.3 This international standard was developed in accor- dance with internationally recognized principles on standard- ization established in the Decision on Principles for the Development of International Standards, Guides and Recom- mendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
3. Terminology
3.1 Definitions: 3.1.1 best effıciency point (BEP), n—the capacity and head in which the pump efficiency is the highest. 3.1.2 BHP, n—power delivered to the pump from the driver in brake horse power. 3.1.3 capacity, n—the total volume output per unit of time. 3.1.4 centrifugal pump, n—a kinetic machine converting mechanical energy into hydraulic energy through rotating motion. 3.1.5 close coupled pumps, n—in this arrangement, no coupling is provided between the pump and the motor shafts, and the pump housing is flange mounted to the motor. The pump impeller is directly mounted to the motor shaft. 3.1.6 coupled pumps, n—in this arrangement, the pump and the motor must use a coupling to transmit the power from the driver to the pump shaft. 3.1.7 gallons per minute (GPM), n—U.S. customary unit for capacity. 3.1.8 head, n—the expression of the energy content of the liquid referred to in any arbitrary datum. It is expressed in units of energy per unit of weight liquid. The measuring unit for head is foot (metre) of liquid. 3.1.9 head, total discharge, n—the sum of the pump’s discharge gauge head, the velocity head at the gauge connection, and the elevation difference between the pump centerline and the gauge centerline. 3.1.10 head, total, n—the measurement of energy increase per unit weight of the liquid, imparted to the liquid by the pump, and is the difference between the total discharge head and the total suction head. 3.1.11 head, total suction, n—the sum of the pumps suction gauge head, the velocity head at the gauge connection, and the elevation difference between the pump inlet centerline and the gauge centerline. 3.1.12 head, maximum rated, n—the most head a pump can generate with the correct impeller diameter for the service conditions. 3.1.13 hydrostatic test, n—applying static pressure to the assembled pump or pressure containing components to deter- mine structural integrity of the unit.3.1.14 maximum allowable working pressure, n—the maxi- mum discharge pressure that could occur in the pump when it is operated at the rated speed and suction pressure for a given application. 3.1.15 maximum BHP rated impeller, n—the highest power required by a pump with the correct impeller diameter for the service condition. 3.1.16 minimum continuous flow, n—the lowest possible flow rate at which the pump can run without generating excessive heat within the unit or damage to the pump. 3.1.17 net positive suction head available (NPSHA), n—the total suction head absolute, determined at the first stage impeller datum, less the absolute vapor pressure ofthe liquid at a specific capacity. 3.1.18 net positive suction head required (NPSHR), n—the amount of suction head over vapor pressure required at the pump to prevent more than a 3 % loss in total head from the first stage of the pump at a specific capacity. 3.1.19 nonmetallic materials, n—any material that would not be recognized as a metal. Examples include plastics, fiberglass resins, carbon fiber, fiberglass-reinforced vinyl ester, polytetrafluoroethylene (PTFE), or any similar material. 3.1.20 non-overloading power characteristics, n—this char- acteristic requires that the driver be sized for the highest possible power requirement from the pump. 3.1.21 OEM, n—original equipment manufacturer of the pump unit. 3.1.22 pounds per square inch absolute (PSIA), n—the U.S. customary measure of pressure with zero as a true absolute zero in pounds per square inch. 3.1.23 pounds per square inch gauge (PSIG), n—the U.S. customary measure of pressure with zero being adjusted to atmospheric pressure in pounds per square inch.