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10 CFR § 431.464 - Test procedure for the measurement of energy efficiency, energy consumption, and other performance factors of pumps.

---
identifier: "/us/cfr/t10/s431.464"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "10 CFR § 431.464 - Test procedure for the measurement of energy efficiency, energy consumption, and other performance factors of pumps."
title_number: 10
title_name: "Energy"
section_number: "431.464"
section_name: "Test procedure for the measurement of energy efficiency, energy consumption, and other performance factors of pumps."
chapter_name: "DEPARTMENT OF ENERGY"
subchapter_number: "D"
subchapter_name: "ENERGY CONSERVATION"
part_number: "431"
part_name: "ENERGY EFFICIENCY PROGRAM FOR CERTAIN COMMERCIAL AND INDUSTRIAL EQUIPMENT"
positive_law: false
currency: "2026-03-24"
last_updated: "2026-03-24"
format_version: "1.1.0"
generator: "[email protected]"
authority: "42 U.S.C. 6291-6317; 28 U.S.C. 2461 note."
regulatory_source: "64 FR 54141, Oct. 5, 1999, unless otherwise noted."
cfr_part: "431"
---

# 431.464 Test procedure for the measurement of energy efficiency, energy consumption, and other performance factors of pumps.

(a) *General pumps*—(1) *Scope.* This paragraph (a) provides the test procedures for determining the constant and variable load pump energy index for:

(i) The following categories of clean water pumps that have the characteristics listed in paragraph (a)(1)(iii) of this section.

(A) End suction close-coupled (ESCC);

(B) End suction frame mounted/own bearings (ESFM);

(C) In-line (IL);

(D) Radially split, multi-stage, vertical, in-line casing diffuser (RSV); and

(E) Submersible turbine (ST) pumps.

(ii) The additional following categories of clean water pumps that have the characteristics listed in paragraph (a)(1)(iii) of this section:

(A) Radially-split, multi-stage, horizontal, end-suction diffuser casing (RSHES);

(B) Radially-split, multi-stage, horizontal, in-line diffuser casing (RSHIL);

(C) Small vertical in-line (SVIL); and

(D) Vertical Turbine (VT).

(iii) Pump characteristics:

(A) Flow rate of 25 gpm or greater at BEP and full impeller diameter;

(B) Maximum head of 459 feet at BEP and full impeller diameter and the number of stages required for testing (*see* section 1.2.2 of appendix A of this subpart);

(C) Design temperature range wholly or partially in the range of 15 to 250 °F;

(D) Designed to operate with either:

(*1*) A 2- or 4- or 6-pole induction motor, or

(*2*) A non-induction motor with a speed of rotation operating range that includes speeds of rotation between 2,880 and 4,320 revolutions per minute (rpm) and/or 1,440 and 2,160 rpm and/or 960 and 1,439 revolutions per minute, and in each case, the driver and impeller must rotate at the same speed;

(E) For ST, and VT pumps, a 6-inch or smaller bowl diameter; and

(F) For ESCC, and ESFM pumps, a specific speed less than or equal to 5,000 when calculated using U.S. customary units.

(2) *Testing and calculations.* Determine the applicable constant load pump energy index (PEI<sub>CL</sub>) or variable load pump energy index (PEI<sub>VL</sub>) using the test procedure set forth in appendix A of this subpart.

(b) *Dedicated-purpose pool pumps*—(1) *Scope.* This paragraph (b) provides the test procedures for determining the weighted energy factor (WEF), rated hydraulic horsepower, dedicated-purpose pool pump nominal motor horsepower, dedicated-purpose pool pump motor total horsepower, dedicated-purpose pool pump service factor, and other pump performance parameters for:

(i) The following varieties of dedicated-purpose pool pumps:

(A) Self-priming pool filter pumps;

(B) Non-self-priming pool filter pumps;

(C) Waterfall pumps; and

(D) Pressure cleaner booster pumps;

(ii) Served by single-phase or polyphase input power;

(iii) Except for:

(A) Submersible pumps; and

(B) Self-priming and non-self-priming pool filter pumps with hydraulic output power greater than or equal to 2.5 horsepower.

(2) *Testing and calculations.* Determine the weighted energy factor (WEF) using the test procedure set forth in appendix B or appendix C of this subpart, as applicable.

(c) *Circulator pumps*—(1) *Scope.* This paragraph (c) provides the test procedures for determining the circulator energy index for circulator pumps that are also clean water pumps, including on-demand circulator pumps and circulators-less-volute, and excluding submersible pumps and header pumps.

(2) *Testing and calculations.* Determine the circulator energy index (CEI) using the test procedure set forth in appendix D of this subpart Y.

[82 FR 36923, Aug. 7, 2017, as amended at 87 FR 57299, Sept. 19, 2022; 88 FR 17978, Mar. 24, 2023]