Customer Service:
Mon - Fri: 8:30 am - 6 pm EST

HI: Hydraulic Institute

HI, the Hydraulic Institute, is a nonprofit organization that develops and publishes pump standards. Headquartered in Parsippany, United States, HI membership includes most major U.S. pump manufacturers as active members. With HI standardization efforts closely linked to those of several other SDOs, HI influence goes on to spread far beyond even its own robust membership. Standards from HI are available both individually, directly through the ANSI webstore, and as part of a Standards Subscription. If you or your organization are interested in easy, managed, online access to standards that can be shared, a Standards Subscription may be what you need - please contact us at: [email protected] or 1-212-642-4980 or Request Proposal Price.

Below are HI's best-selling standards. To find additional standards, please use the search bar above.

 Back to All Publishers Home

ANSI/HI 9.6.2-2021

Rotodynamic Pumps for Assessment of Applied Nozzle Loads

In this revision, the committee developed new content on nozzle load evaluations including: mechanical pipe strain forces, hydraulic pressure reaction forces, thermal growth or contraction forces, pump casing stresses and deformation, relative movement between stationary and rotating components, shaft misalignment, hold down bolts, base plate stresses and deflection, and anchor-bolt stresses. In addition, normative content was added or updated to address material adjustment factors related to temperature.

ANSI/HI 14.6-2022

Rotodynamic Pumps for Hydraulic Performance Acceptance Tests

This standard provides acceptance criteria and uniform procedures for performance, net positive suction head, and hydrostatic pressure testing, and data recording and reporting of test results for rotodynamic pumps. It provides acceptance grades that can be specified for various types of applications. It also defines test procedures that will result in consistent and repeatable results.

ANSI/HI 9.6.6-2022

Rotodynamic Pumps for Pump Piping

This is a revision of the 2016 edition. This standard applies to inlet (suction) and outlet (discharge) piping for rotodynamic pumps in all worldwide markets. It identifies and details the required and recommended practices forpump piping. Major updates in this revision includes a format change to aid users to more easily identify and reference requirements of the standard. Technical updates were made throughout the standard, and changes to some straight pipe length requirements following flow disturbing fittings and prior to the pump inlet were made.

ANSI/HI 9.6.4-2022

Rotodynamic Pumps for Vibration Measurement and Allowable Values

This standard applies to rotodynamic pumps and covers the evaluation of vibration when the vibration measurements are made on stationary parts associated with bearings (bearing housings). It provides specific maximum allowable vibration values measured on bearing housings of rotodynamic pumps in field and factory test environments. Topics covered in this standard include bearing housing vibration measurement, speeds above and below 600 rpm, vibration measurement instrumentation, vibration acceptance levels for field and factory tests, acceptance test installation and operating conditions, allowable pump bearing housing vibration, suggested vibration test report, factors affecting vibration, vibration criteria at the top of the motor for vertical pumps.

ANSI/HI 9.8-2018

Rotodynamic Pumps for Pump Intake Design

Ideally, the flow of liquid into any pump should be uniform, steady, and free from swirl and entrained air. Lack of uniformity through inlet connection can result in pumps not operating to optimum design condition and at a lower hydraulic efficiency. This technically advanced standard discusses the proper design for rectangular intakes, formed suction intakes, circular pump stations, trench-type intakes for clear liquids and for solids-bearing liquids, tanks – pump suction, can vertical turbine pump intakes, unconfined intakes, and circular plan wet pit for solids-bearing liquids.

ANSI/HI 9.6.1-2017

Rotodynamic Pumps Guideline for NPSH Margin

The purpose of this guideline is to establish recommended net positive suction head available (NPSHA) above the published NPSH required (NPSHR) that will lead to acceptable pump performance and service life.

ANSI/HI 11.6-2017

Rotodynamic Submersible Pumps: for Hydraulic Performance, Hydrostatic Pressure, Mechanical and Electrical Acceptance Tests

This standard applies to customer acceptance testing of rotodynamic submersible pumps driven by electric motors, unless otherwise agreed or specified. A submersible pump is defined as a close-coupled pump/motor unit designed to operate submerged in the pumped liquid. This definition includes submersible pumps operating in either a wet-pit or dry-pit environment.

ANSI/HI 9.6.7-2015

Rotodynamic Pumps - Guideline for Effects of Liquid Viscosity on Performance

ANSI/HI 9.6.7 outlines the method for predicting performance of rotodynamic pumps in Newtonian liquids of viscosity greater than water. The standard applies to single and multi-stage rotodynamic pumps having radial impellers ns = 60, (Ns = 3000), handling liquids exhibiting Newtonian behavior, and a kinematic viscosity greater than 1 and less than 4000 centistokes.

ANSI/HI 9.6.3-2017

Rotodynamc (Centrifugal and Vertical) Pumps - Guideline for Allowable Operating Region

This guideline discusses the effects of operating a rotodynamic pump continuously or for a long duration at rates of flow greater than or less than the pumpÆs best efficiency point (BEP) rate of flo

ANSI/HI 9.6.5-2016

Rotodynamic Pumps Guideline for Condition Monitoring

This guideline is for rotodynamic pumps, including both sealed and sealless pump designs as stated in each section.


As the voice of the U.S. standards and conformity assessment system, the American National Standards Institute (ANSI) empowers its members and constituents to strengthen the U.S. marketplace position in the global economy while helping to assure the safety and health of consumers and the protection of the environment.