UL 448:2017 Centrifugal Stationary Pumps for Fire-Protection Service.
1.1 These requirements cover centrifugal fire pumps intended for use in water-supply systems for fire-protection service.
1.2 The pumps covered by these requirements are intended for installation and use in accordance with the Standard for the Installation of Stationary Pumps for Fire Protection, NFPA 20.
2.1 Except as indicated in 2.2, a component of a product covered by this standard shall comply with the requirements for that component.
2.2 A component is not required to comply with a specific requirement that:
a) Involves a feature or characteristic not required in the application of the component in the product covered by this standard, or
b) Is superseded by a requirement in this standard.
2.3 A component shall be used in accordance with its rating established for the intended conditions of use.
2.4 Specific components are incomplete in construction features or restricted in performance capabilities. Such components are intended for use only under limited conditions, such as certain temperatures not exceeding specified limits, and shall be used only under those specific conditions.
3 Units of Measurement
3.1 Values stated without parentheses are the requirement. Values in parentheses are explanatory or
4 Undated References
4.1 Any undated reference to a code or standard appearing in the requirements of this standard shall be interpreted as referring to the latest edition of that code or standard.
5.1 For the purposes of this standard, the following definitions apply.
5.2 CORROSION-RESISTANT MATERIAL — A material having resistance to corrosion equivalent to or exceeding that of a brass, bronze, monel, or Series 300 stainless steel alloy.
5.3 PRESSURE, MAXIMUM NET — The maximum net pressure developed by the pump at the rated speed which typically occurs at or near shutoff pressure.
5.4 PRESSURE, MAXIMUM WORKING — For performance tests specified in this standard, the maximum pressure developed at the pump discharge flange under any condition of intended use determined by the sum of the maximum net pressure developed by the pump and the allowed positive suction pressure. For production tests, this value may be lower, based on the conditions imposed by the particular installation for which the pump is constructed. The maximum net pressure and maximum positive suction pressure that are marked on the pump are those that indicate the acceptability of a pump (the limiting pressures) for an installation.
5.5 PRESSURE, NET (TOTAL HEAD):
a) For a split-case, end-suction, in-line pump, multistage multiport, or a vertical-turbine pump in a suction vessel, the algebraic difference in psi (kPa) between pressures measured at the
discharge flange and at the suction flange, corrected to the pump centerline and corrected for differences in velocity head at the points of gauge attachment.
b) For a vertical-turbine pump in a sump or well, the pressure measured by a pressure gauge attached just beyond the discharge head, corrected for the velocity head at the point of gauge attachment and for the vertical distance from the pumping water level to the center of the gauge.UL 448 pdf download.