Jiangsu Haifa Machinery Manufacturing Co., Ltd.

Application of API 610 OH6 High-Speed Integral Gear-Driven Pumps in High-Pressure, Low-Flow Chemical Process Units

1. Demand for OH6 High-Speed Pumps in High-End Petrochemical Units

With the development of the refining, ethylene, coal chemical, natural gas chemical, and new energy industries, process units continue to evolve toward larger scale and higher parameters. In certain high-pressure, low-flow continuous conveying conditions, traditional multistage centrifugal pumps suffer from issues such as excessive stage counts, large structural dimensions, and complex maintenance. The OH6 high-speed integral gear-driven-stage overhung pump defined in API 610 employs a high-speed impeller design, utilizing a gear speed-increasing mechanism to raise the pump shaft speed, enabling a single-stage impeller to achieve relatively high head output. This makes it particularly suitable for high-pressure-ratio, low-flow,-reliability operating conditions. At present, OH6 pumps are widely used in refinery hydrotreating units, ethylene cracking units, propane dehydrogenation (PDH aromatics complex units, coal-to-chemicals, and new energy chemical systems.

1. Structural Characteristics of API 610 OH6 Pumps

The OH6 pump is a high-speed overhung centrifugal pump defined by API 610. main structural features include:

1. Single-stage overhung impeller configuration

2. Integral gear speed-increasing gearbox

3. High-speed output shaft system

4. High-speed bearings and lubrication system- API 682 mechanical seal configuration

Compared with conventional OH2 process pumps, the OH pump enhances unit-stage energy conversion capability by increasing impeller peripheral speed, allowing higher head to be achieved within a more compact equipment footprint. Typical application parameters:

1. Flow rate: low to medium flow range

2. Head: high-head operating conditions

3. Speed: typically higher than standard motor-driven pumps

4. Operating characteristics: continuous operation, infrequent start-stop cycles, high reliability requirements

Therefore, the OH6 pump not a replacement for standard process pumps, but rather an optimized solution for specific high-energy-density operating conditions.

1. Typical Applications of OH6 Pumps in Chemical Process Units

3.1 High-Pressure Injection Systems in Hydrotreating Units

In hydrocracking and hydrotreating units, certain process media must be continuously conveyed to high-pressure reaction systems. Such conditions typically feature:

1. High system pressure




2. Relatively low flow rates




3. Flammable media




4. Long continuous operating cycles

The OH6 high-speed pump utilizes a high-speed impeller to relatively high head, reducing the number of stages required compared with traditional multistage pumps and improving equipment compactness.

32 Liquid Booster Systems in Ethylene and Propylene Units

Liquid hydrocarbon media in ethylene cracking and PDH units typically exhibit high saturated vapor pressure, imposing stricter requirements on cavitation performance and operational stability. Key design considerations for OH6 pumps include:

1. NPSH margin




2. Inducer design




3. High-speed rotor stability




4. seal reliability

By optimizing the hydraulic model, cavitation can be reduced and long-term unit operability improved.

3.3 Coal Chemical and Methanol Units

In large-scale coal-to-methanol and syngas-to-chemicals projects, high-pressure low-flow pumps are primarily applied in:

1. Process liquid injection




2. Catalyst circulation systems




3. Special additive conveying




4. High-pressure auxiliary processes

The compact structure of the OH6 high-speed pump helps reduce unit footprint and improves system layout efficiency.

1. Key Technologies in OH6 Pump Design

4.1 High-Speed Rotor Dynamics Design

Due to the relatively high operating speed of OH6 pumps, the design phase requires:

1. Rotor Dynamic Analysis

Critical Speed Analysis
-balance Response Analysis

Through high-speed rotor calculations, resonance during pump operation is avoided, improving continuous operation reliability.

4.2 API 682 Mechanical Seal Systems

In the petrochemical industry, OH6 pumps are typically with API 682 mechanical seal systems based on media characteristics. Common arrangements include:

1. API Plan 11




2. API 21




3. API 23




4. API 52/53A




5. API Plan74

For high-temperature flammable, or toxic media, double mechanical seals may be employed to enhance equipment safety levels.

1. Material and Manufacturing Requirements

Given the complex long-term operating environment of OH6 pumps,etted components must be selected according to the media:

1. 316 stainless steel

2. 2205/2507 duplex stainless steel

3. 904L

4. Alloy 20

5. Hastelloy C series materials

In addition, high-speed rotating components require precision machining, high-speed dynamic balancing, and operational verification.

1. Jiangsu Haifa API 610 Process Pump Technology Applications

Jiangsu Haifa Machinery Manufacturing Co.,. has long been engaged in the R&D and manufacturing of petrochemical process pumps, with products covering the API 610 OH series, BB series double-casing multistage pumps, VS series vertical barrel pumps, and API 685 sealless magnetic drive pumps. The company's products are designed manufactured in accordance with:

1. API 610 / ISO 13709

2. API 682

3. API 685- ISO 5199and other international standards.

For refining, coal chemical, natural gas, new energy, and fine chemical projects, Jiangsuifa provides complete process pump solutions including: Pump selection

1. Hydraulic design

2. Material optimization

3. Seal scheme design

4. Operational reliability analysis

Website: www.jslgpump.com

1. Technical Reference Standards and Literature

API Standard 610 / ISO 13709 — Centrifugal Pumps for Petroleum, Petrochemical and Natural Gas Industries This standard specifies structural, performance, material, vibration, and reliability requirements for centrifugal pumps in the petroleum, petrochemical, and natural gas industries, serves as an important basis for OH6 high-speed pump design.

API Standard 682 — Pumps — Shaft Sealing Systems for Centrifugal and Rotary Pumps
Used to guide mechanical seal system design for petrochemical pumps, specifying requirements for high-speed pump seal selection, auxiliary systems, and operational reliability.

API RP 684 — Tutorial on the API Standard Paragraphs Covering Rotor Dynamics and Balance
Provides guidance on rotor dynamics analysis and balancing techniques for high-speed rotating equipment.

Gülich J.F. — Centrifugal Pumps, Springer
This professional reference systematically presents centrifugal pump hydraulic design, cavitation performance, efficiency optimization, and high-speed pump design theory.

ISO 1940-1 Mechanical Vibration — Balance Quality Requirements for Rotors
Specifies dynamic balance quality grade requirements for rotating components, providing a basis for high-speed pump rotor manufacturing.

Conclusion

As modern chemical process units advance toward higher parameters, greater efficiency, and intelligent operation, the API 610 OH6 high-speed integral gear-driven pump will play an increasingly important role in high-pressure, low-flow systems. Through high-speed hydraulic design, advanced rotor analysis technology, and API-standardized manufacturing systems, OH6 pumps are capable of meeting long-term continuous operation requirements in refining, coal chemical, and new energy sectors. Jiangsu Haifa Machinery Manufacturing Co., Ltd. will continue focus on R&D of API 610 process pumps, high-speed pumps, and special-condition pumps, providing safe, efficient, and reliable pump equipment for the global chemical industry.