Hydraulic Institute Specification for General Purpose Overhung Rotodynamic Pumps

By Peter Gaydon, Deputy Executive Director

The Hydraulic Institute (HI) was established in 1917 (105 years ago) and shortly afterward began developing standards. In 1983, the standards were published in a 369-page hardcover blue book that was titled Hydraulic Institute Standards 14th edition. The blue color of the book is referenced because HI still receives inquiries and comments about it, and they emphasize the “blue book.”

Since that time, HI has expanded its standards to cover many thousands of pages of content with most subjects being a single standard, guideline or guidebook. The expansion of the publications allowed HI to cover more topics and, in more depth, as required by the industry. However, the downside to this is that it became confusing as to what standard or guideline was needed. For example, when a specification simply states, “per Hydraulic Institute Standards,” the manufacturer does not know what the specifier intended.

As a first step to provide clarity, a HI committee of pump manufacturers and engineering procurement and construction (EPC) companies published HI 30.1 Specification for General Purpose OH1 Rotodynamic Pumps. The specification is available as a free download at pumps.org/standards. It provides users with clearer and more precise specifications and gives the pump manufacturer reassurance that the contents within have been vetted by the industry. It also serves the specifying engineer by providing requirements they can easily implement, help them find the appropriate standard references and offers “notes to specifier” for further consideration. To aid the specifier in adopting the requirements into their specifications, it was written consistent with the Construction Specification Institute (CSI) three-part format as follows:

Part 1: General requirements, such as submittal documents, delivery, storage and handling, quality and warranties.

Part 2: Product requirements, describes products, materials, equipment, fabrication, systems, assemblies, their quality requirements, service conditions and performance criteria, factory testing and spare parts.

Part 3: Execution, deals with the scope of work to be performed during the installation, field testing and startup of the equipment on-site.

Part 1: General Requirements

Part 1 of the specification defines the scope and summarizes the applicable pump types. It outlines reference standards, nomenclature, definitions and details the allowance of alternate designs. It also provides descriptions of what the responsibilities are for the purchaser, vendor and contractor.

An OH1 pump is a rotodynamic pump that is horizontal, overhung, flexibly coupled and has a foot mounted casing as defined in ANSI/HI 14.1-14.2 Rotodynamic Pumps for Nomenclature and Definitions. The scope of the specification is OH1 Rotodynamic Pumps (Image 1), but limited to general service pumps with certain attributes as follows:

• rotation clockwise or counterclockwise
• semi-open or enclosed impeller
• radial and mixed flow single stage end suction pumps
• clear liquids (solids less than 2% by volume)
• nonhazardous, nonflammable, nontoxic liquid
• rate of flow up to 2270 cubic meters per hour (m3/h) (10,000 gallons per minute [gpm])
• operating temperature range: -30 to 175 C (-20 to 350 F)
• working pressure: up to 25 bar (260 pounds per square inch [psi])
• specific speeds up to 120 metric units (6,000 U.S. customary units)

Part 2: Product Requirements

The product requirements section covers the minimum requirements for application data, factory testing, materials of construction, casing and pressure containing components, impeller, power end, shaft and shaft sleeves, shaft seals, static sealing, coupling, guards, driver, baseplate and auxiliary piping and tubing. This section of the specification contains the bulk of the pump design and factory testing requirements, which typically includes options for the specifier to consider. An example of this is related to the shaft seal for the pump. Included below are sections 30.1.2.4 and 30.1.2.9 from the specification, which provide examples of how guidance and references are provided in addition to the requirements. This allows for flexibility and enables the specifier to optimize the requirements for the application.

30.1.2.3 Factory testing requirements

Note to Specifier: Field testing and commissioning is covered in Part 3. Test requirements shall be identified by the specifier in the data sheet and/or inspection and test plan.

30.1.2.3.1 Hydraulic performance shall be verified per ANSI/HI 14.6. The purchaser may specify certified testing, acceptance grades and other tests per ANSI/HI 14.6.

30.1.2.3.2 A hydrostatic test shall be performed per ANSI/HI 14.6 Appendix B.

30.1.2.3.3 Assembly check reports (clearances/fits as dictated by the vendor, unless otherwise agreed upon).

References: [13] ANSI/HI 14.6, [17] BS EN 10204

30.1.2.9 Shaft seal

Note to specifier: Consult vendor and refer to HI Mechanical Seals for Pumps: Application Guidelines for seal selection and auxiliary systems.

30.1.2.9.1 The shaft seal shall be compression packing or single mechanical seal (cartridge or component type).

30.1.2.9.2 If pump is designed with a packed box sealing system, the specifier may request wear resistant material combinations on the rotating surfaces in direct contact with packing, e.g. hardened materials, metallic coatings, ceramic coatings, composite materials.

References: [16] HI Seal Guidebook

Part 3: Execution

The execution section provides requirements and allowances for installation, physical inspection, field performance testing, operation testing and field painting. Just as important to a successful project as the design requirements in Part 2, are the execution of the items in Part 3. Perhaps the most important aspect for a pumping system to be reliable is proper installation and operational checks, which is covered in this section. Examples of the installation and operational testing requirements are provided for reference, which clearly state the requirements and all responsible parties.

30.1.3.1 Installation

30.1.3.1.1: Contractor shall install the pumping units in accordance with the instructions provided by the vendor and as indicated on the approved drawings.

30.1.3.1.2: Installation shall include furnishing the required oil and grease for initial operation by the contractor. The grades of oil and grease shall be in accordance with the vendor’s recommendations.

30.1.3.1.3: Prepare the surfaces of the foundation and baseplate for grout, as required by the grout vendor’s instructions.

30.1.3.1.4: Any field modifications or changes required shall be documented and approved by purchaser or owner
as required. As-built/as-installed drawings are to be retained and placed with the IOM and other records for the life of the equipment.

References: [11] ANSI/HI 14.3, [12] ANSI HI 14.4, [9] ANSI/HI 9.8, [7] ANSI/HI 9.6.6, [3] ANSI/HI 9.6.2

30.1.3.4 Operation Testing

Note to Specifier: If a system operational demonstration is required, the specifier should produce a detailed operational plan. Owner/operator of equipment should mutually agree upon the sequence and duration of operational testing.

30.1.3.4.1: Operational requirements and duration shall be specified for each system.

30.1.3.4.2: After field performance testing has been completed and accepted, provide an operational test demonstrating the system(s) is functioning as specified and indicated with all instrumentation and control functioning in the automatic mode (as applicable). The system shall be operated and maintained in a continuous online and demonstrate
full-function for test duration. Time for filling, draining, flushing, stabilizing, adjusting or any other startup activity shall not be included in the test
duration time.

30.1.3.4.3: Upon any failure, the contractor shall remedy the situation, reschedule and retest without any operational demonstration time having accrued unless otherwise determined by the Owner.

Specifications can be complex; therefore, the requirements stated within need to be clearly understood, provide guidance and reference the appropriate standards. This specification is the first of its kind developed by HI in an effort to achieve these goals and provide clarity to what is meant by “per Hydraulic Institute Standards.” The success and usefulness of this specification document will determine if additional specifications will be developed, or if the current scope
needs to be expanded upon. This would include, but is not limited to other overhung types, vertically suspended or between bearing pumps.

Download the specification for free at pumps.org/standards and use it for reference, to develop specifications or provide feedback in the comment form.

This blog was originally posted on Pumps & Systems on February 20, 2023.

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