API610 OH2  pump is "Overhung, Radially Split, Back Pull Out", which means cantilever, radial splitting, and rear pull-out. All of its structural designs revolve around a core concept: maximizing maintenance convenience and minimizing downtime.
Parameter project OHH series
Flow rate up to 2250 m ³/h
Lift up to 360 meters
Maximum working pressure 75 bar
Suitable temperature range: -75 ° C to+425 ° C.

Suitable for pumping clean and slightly polluted, cold or hot, chemically or aggressive liquids
In refineries
In petrochemical plants
In cryogenic engineering
In coal processing
In chemical industry, fibre industry and general processing industry
In auxiliary circuits of power plants
In medium-sized and large heating and air-conditioning plants
In environmental protection engineering
In offshore industry and seawater desalination plants

Product attributes:

Maximum head :>150m

Maximum fiow:>400L/min

Driving type:Motor

Working impeller number:Single-Stage Pump

Working impeller inlet way:Middle Pressure Pump

Pump shaft positon:Horizontal Pump

Pump shell combination:Horizontal Split Pumps

Installation height:Suction Centrifugal

Impeller structure:Closed

Transportation package:Wooden Case

Specification:API 610 standard

Origin:Dalian,Liaoning,China

Size:DN25~400

Flow:0~4000m3/H

Head:0~300m

Temperature:-80~450 Degress Celsius

Pressure:~5MPa

Material:
Carbonsteel; chromed steel; austeniticstainlesssteel; duplexsteel; Titanium and Titanium Alloys; Hastelloy C-276 and other special materials; It depends the customer's request.

1. OHH series (universal main type)
This is the most widely used OH2 pump by Sulzer, with the widest range of models in the industry, suitable for most heavy-duty conditions such as refining, petrochemicals, and offshore platforms.

Parameter project OHH series
Flow rate up to 2250 m ³/h
Lift up to 360 meters
Maximum working pressure 75 bar
Suitable temperature range: -75 ° C to+425 ° C.

The optional 600 # flange means that the pump body has the potential to withstand higher pressures.
The export size ranges from 25 to 400 mm, and the interface size covers a wide range.
The maximum speed can reach up to 3600 rpm, which is a typical direct coupled speed of a power frequency motor.
The core design has twice the load capacity of API 610 nozzle, rigid shaft, finned fan cooling bearing box, and containerized mechanical seal (API 682), which are known for their extremely high reliability and can withstand greater pipeline stress.

OHHL series (low flow high lift type)
Specially designed to fill the gap in the low flow region of the OHH spectrum, especially suitable for light hydrocarbons, high-pressure replenishment, and other working conditions.

Parameter project OHHL series
Flow rates ranging from 1 to 60 m ³/h are focused on the low flow range.
The head of 20 to 450 meters achieves extremely high head at low flow rates.
The maximum working pressure of 51 bar meets the requirements of low flow and high pressure.
Suitable for a wide temperature range of -75 ° C to 425 ° C, consistent with the OHH series.
A smaller outlet diameter ranging from 25 to 50 mm.
The core design features a unique low flow impeller and diffuser design, achieving a stable head flow curve; The core components such as bearings and seals are fully compatible with the OHH series, significantly reducing spare parts inventory. The universality of components is the core economic advantage of the Sulzer OH2 pump family.

PRELF series (extremely low flow type)
When the flow demand is extremely low and conventional pumps are difficult to operate efficiently and reliably, PRELF is a specially optimized solution.

Parameter project PRELF series
The minimum flow rate covers extremely low flow conditions starting from 3 m ³/h.
A head of up to 210 meters can still ensure a high head at extremely low flow rates.
The maximum working pressure of 40 bar is suitable for medium pressure systems.
The applicable temperature range of -46 ° C to 180 ° C is slightly narrower compared to OHH/OHHL, but still covers most chemical working conditions.
Core design: Sulzer designed multi blade open radial impeller; The head curve is stable; The impeller and shell can be cut to precisely match the Best Efficiency Point (BEP); Optional inducer to meet low NPSH requirements. This is a pump that can be customized for cutting to solve challenging low flow centrifugal pump conditions.
3. Summary
Sulzer's OH2 pump family achieves full flow coverage from 3 m ³/h to 2250 m ³/h through three series, capable of withstanding temperatures up to 425 ° C and pressures up to 75 bar.

General operating conditions: Choose the OHH series.

Low flow and high head operating conditions: Choose the OHHL series (which can share spare parts with OHH).

For extremely low flow or special demand conditions: choose the PRELF series.

I hope this detailed technical parameter will be of direct help to your selection work. If you need to recommend pump types for a specific operating condition (such as specific medium, temperature, and flow rate), we can continue to explore.

Product attributes:   Maximum head :>150m   Maximum fiow:>400L/min
   Driving type:Motor   Working impeller number:Single-Stage Pump   Working impeller inlet way:Middle Pressure Pump   Pump shaft positon:Horizontal Pump   Pump shell combination: Horizontal Split Pumps         Installation height:Suction Centrifugal   Impeller structure:Closed   Transportation package:Wooden Case  Specification:API 610 standard  Trademark:Dalian Kehuan Pump Co.,Ltd  Origin: Dalian,Liaoning,China  

The OH2 pump family achieves full flow coverage from 3 m ³/h to 2250 m ³/h through three series, and can withstand temperatures up to 425 ° C and pressures up to 75 bar.

General operating conditions: Choose the OHH series.

Low flow and high head operating conditions: Choose the OHHL series (which can share spare parts with OHH).

For extremely low flow or special demand conditions: choose the PRELF series.

I hope this detailed technical parameter will be of direct help to your selection work. If you need to recommend a pump type for a specific working condition (such as specific medium, temperature, and flow rate), we can continue to explore

Size:DN25~400 Flow:0~4000m3/H
 Head:0~300m
 Temperature:-80~450 Degress Celsius Pressure:~5MPa Material: 
 Carbonsteel; chromed steel; austeniticstainlesssteel; duplexsteel; Titanium and Titanium Alloys; Hastelloy C-276 and other special materials; It depends the customer's request.   
 S-5  S-6  C-6  S-8  A-7  A-8  D-1  D-2   Casing  Cast steel  Cast steel  CA15/CA6NM  Cast steel  AUST SS  316 AUS  DUPLEX  SUPER DUPLEX   Impeller  Cast steel  12%CR  CA15/CA6NM  316 AUS  AUST SS  316 AUS  DUPLEX  SUPER DUPLEX   Shaft  AISI4140  AISI4140  SS420  316N  AUST SS  316N  2205  2507   Wear rings  12%CR  12%CR  12%CR  316 Hard faced  AUST SSHard faced  316 Hard faced  Duplex Hard faced  SUPER Duplex 
Hard faced   Bearing Frame  Cast steel  Cast steel  Cast steel  Cast steel  Cast steel  Cast steel  Cast steel  Cast steel

The following is a breakdown of its iconic structural features:

Structural features and design essence
1. The pull-out design is the most iconic feature of OH2. The bearing frame (bracket) of the pump is separated from the pump body and connected through a separate "intermediate frame". During maintenance, simply remove the bolts between the pump body and the intermediate frame to pull out the entire rotor components (impeller, shaft, seal, bearing frame) as a whole, without dismantling the inlet and outlet pipelines and motor. This greatly simplifies maintenance work.
2. The radial split pump body is horizontally split at the axis centerline. This is not only convenient for casting and processing, but also for inspecting the pump casing and sealing chamber when needed.
3. The bearing arrangement adopts a bearing frame supported at both ends, with the bearings located on the other side of the impeller, providing stable support. Bearings are usually paired angular contact ball bearings (used to withstand radial and axial loads) or a combination of cylindrical roller bearings and thrust bearings.
4. The sealing chamber provides standard sealing chamber sizes that comply with API 682 standards, and can be installed with single end, double end, or series mechanical seals, even packing seals, with strong adaptability.
5. The sealing flushing, cooling, and bearing cooling interfaces specified in the standard API scheme for cooling and flushing ensure safe operation under high temperature conditions.
🏭  The main application industries of OH2 pump
Due to its sturdy, reliable, and easy to maintain characteristics, OH2 pumps are almost used in all process industries that require the transportation of clean or slightly particulate liquids, especially in situations where temperature and pressure are moderate but reliability is extremely high.

Why are typical working conditions and sections in the application industry the main venue for OH2?
Petrochemical industry - Feed pumps, reflux pumps, and circulation pumps for various types of towers (such as distillation towers and absorption towers)
• Solvent transfer pump
Hot water/hot oil circulation pump (temperature up to 400 ° C) temperature resistance: The separated bearing frame design has minimal thermal expansion, making it particularly suitable for high temperature conditions.
Convenient maintenance: The chemical plant plans frequent maintenance, and the rear pull design saves a lot of time.
Side line pumps and product pumps for refining and atmospheric/vacuum distillation units
• Slurry pump for catalytic cracking (mild particles)
Standardization and reliability of light oil pumps with high temperatures in hydrogenation units: fully compliant with API standards, meeting the requirements for long-term operation of refineries.
Chemical Industry • Material Diversity for Various Acid, Alkali, and Organic Media Transfer Pumps: A wide range of material options are available, from carbon steel and stainless steel to high alloy and non-metal materials.
Oil and gas storage and transportation, crude oil and refined oil loading and unloading, and pipeline transportation pumps are efficient and reliable: with a wide range of flow and head, they can adapt to continuous heavy load operation.
Energy and Public Works • Boiler Feedwater Pump (Medium Pressure), Condenser Recovery Pump
Balancing economy and reliability of process water booster pumps: while meeting pressure requirements, the total cost of ownership is low.
⚖️  Advantages, disadvantages, and positioning of OH2 pump
In order to visually demonstrate the precise positioning of the OH2 pump, the following figure analyzes its core value and applicable boundaries:

🔄  OH2 vs. OH3: Classic Choice
This is the most common comparison in selection, as the two account for over 95% of the market for OH type pumps.

Features OH2 (rear pull-out) OH3 (integral/front pull-out)
The bearing frame is separated from the pump body and connected through an intermediate frame. Integrate with the pump body as a whole.
Maintenance method: Pull out the entire rotor component backwards. To pull out the rotor component forward, the impeller needs to be removed first.
Excellent adaptability to high temperatures. The bearing frame is independent, and thermal expansion has little impact on the center. Generally. The overall structure is prone to deformation at high temperatures, which affects the center.
The structural length is relatively long (due to the presence of a middle frame). More compact, with a smaller footprint.
The cost is usually higher (with more parts). Usually lower.
Typical applications require high temperatures, important conditions, and frequent maintenance. Normal temperature, general, pursuing compact and economical working conditions.
The Golden Rule of Selection:

Medium temperature>150 ° C, or high maintenance frequency ->OH2 is preferred.

Medium temperature<150 ° C, compact space, limited budget ->optional OH3.

Summary: API 610 OH2 pump is the benchmark for "reliability and maintainability" in the process industry. It may not be the cheapest or most compact option, but when production continuity is crucial, especially in the face of high temperature conditions and scheduled maintenance, OH2 offers unparalleled convenience and peace of mind through its classic 'rear pull-out' design. Choosing OH2 means choosing the most robust guarantee that has been validated for decades for critical processes.

Technical characteristics and application industries of Sulzer OH2 pump.
Firstly, it needs to be clarified that OH2 is not a specific pump model, but an internationally recognized code for a pump type (short shell, two end support, single-stage, horizontal, radial split core pump) defined by the API 610 standard. Sulzer is a leading global pump manufacturer, and its pump series that complies with the API 610 OH2 standard is the SCC series. Therefore, when we talk about the technical characteristics of Sulzer OH2 pumps, we actually refer to the core technology and design advantages demonstrated by Sulzer SCC series pumps in meeting and exceeding API 610 OH2 requirements.
1、 Core technical features of Sulzer OH2 pump (SCC series)
The design of the Sulzer SCC series not only complies 100% with the strict API 610 standard, but also incorporates Sulzer's patented technology and engineering experience, making it outstanding in reliability, efficiency, and maintainability.
Durable and reliable overall design
Heavy duty bearing seat: Adopting a highly rigid heavy-duty bearing seat, it can effectively absorb pipeline loads and vibrations, ensuring long-term stable operation of the rotor.
Centerline support: The pump casing adopts a centerline support design. This means that regardless of changes in operating temperature, the center height of the pump remains unchanged, effectively avoiding alignment failure caused by thermal expansion and contraction, which is a key design under high temperature conditions.
Back to back bearing arrangement: Angular contact ball bearings (bearing axial force) adopt a "back-to-back" arrangement, which can withstand bidirectional thrust and effectively control the axial movement of the rotor, improving operational stability.
Excellent hydraulic performance and high efficiency and energy saving
Advanced hydraulic model: Based on rich experience and CFD (Computational Fluid Dynamics) optimization, the hydraulic design of impellers and volutes is efficient, with a wide efficiency zone and good anti cavitation performance.
Adjustable impeller clearance: With optional impeller wear rings and shell wear rings, the operating clearance can be easily adjusted and restored to maintain high efficiency during long-term operation.
Excellent sealing and shaft sealing solutions
Wide sealing compatibility: The shaft seal area is designed flexibly and can easily adapt to various sealing forms:
Mechanical seal: Supports all API solutions such as single end face, double end face, series connection, dry gas seal, etc., and is equipped with efficient seal flushing solutions (PLAN 11, 21, 23, 32, 52, 53, etc.).
Packing seal: Packing box can also be configured.
Containerized seal: It is recommended to use containerized mechanical seals, which are easy to install, have good sealing performance, and do not require on-site adjustment.
Excellent maintenance friendliness
Rear pull-out design: The entire rotor component (including bearings, mechanical seals, impellers, etc.) can be fully extracted from the rear end of the pump casing without moving the pump body and inlet/outlet pipelines. This greatly facilitates inspection, maintenance, and replacement, reducing downtime.
Standardization and modularization: Many components have a high degree of standardization, making it easy to manage and replace spare parts.
Flexibility in material selection
We provide a variety of material combinations, including carbon steel, stainless steel (such as 316L), duplex steel, super duplex steel, Hastelloy alloy, titanium, etc., to meet the transportation needs of ordinary water, oil products, strong corrosive and high-temperature media.
Comprehensive monitoring and diagnostic options
It can be equipped with complete API monitoring instruments, such as bearing temperature sensors, vibration probes, etc., and support integration into equipment health management systems to achieve predictive maintenance.
2、 Main application industries
Due to its high reliability, high temperature and pressure resistance, and suitability for harsh media, Sulzer OH2 (SCC) pumps are the preferred choice for the following key industrial applications:
Oil and Natural Gas
Refinery: Hot oil pumps, feed pumps, reflux pumps, product pumps in atmospheric and vacuum distillation units, catalytic cracking, hydrocracking, delayed coking and other units.
Petrochemical industry: Heat medium pumps, tower bottom pumps, and feed pumps for ethylene, propylene, aromatic hydrocarbon and other equipment.
Long distance pipelines: main pumps and booster pumps for transporting crude oil and refined oil products.
Chemical and Petrochemical Industry
Various process pumps are used to transport high temperature, high pressure, toxic, harmful, flammable, explosive or valuable chemicals.
For example, the transportation of media such as benzene, toluene, xylene, solvents, monomers, polymers, etc.
Energy and Electricity
Thermal power plant: pre pump for boiler feedwater pump, condensate pump, hot water circulation pump.
Geothermal power generation: high-temperature geothermal brine transfer pump.
other industries
Liquefied natural gas: High pressure transfer pumps in LNG receiving stations.
Coal chemical industry: high temperature and high pressure sections such as coal gasification, coal liquefaction, and methanol to olefin production.
Steel industry: transportation of light oil, wash oil and other media in coking plants.
summary
The Sulzer OH2 pump (i.e. its SCC series) represents the industrial standard for high-end process centrifugal pumps. Its technical features revolve around the compliance and transcendence of API 610 standard, with centerline support, rear pull-out design, and heavy-duty bearing structure being the cornerstone to ensure its long-term, fault free, and easy to maintain operation under high temperature, high pressure, and harsh working conditions. It is almost applied in all heavy process industries that have strict requirements for the reliability of pump equipment, and is a key equipment to ensure safe, continuous, and efficient production in factories. Technical characteristics and application industries of Foss OH2 pump
Okay, we will provide you with a detailed analysis of the technical characteristics and application industries of Flowserve OH2 pumps. Similar to Sulzer, Volkswagen's OH2 pump also fully complies with the API 610 standard and is its flagship product line that has been tested for a long time. The most famous and widely used OH2 pump by Volkswagen is the API OH2/API OH3 series (such as the OH2/OH3 horizontal multi-stage pump, which is also commonly classified as such), but when it comes to standard single-stage two end supported OH2 pumps, their classic representative is the "Durco" Mark 3 series and subsequent optimized models.
Flowserve OH2 pump integrates the technical essence of several famous brands (such as Durco and Byron Jackson), and its core features are as follows:
1、 Key Technical Features of Foss OH2 Pump
Volkswagen's design philosophy emphasizes operational reliability, full lifecycle cost optimization, and global service support while meeting API standards.
Durable 'heavy-duty' design
Heavy duty bearing body: Using heavy-duty and large-sized bearing housings, it provides excellent rigidity, effectively isolates external pipeline stress, and ensures long-term stability of the alignment accuracy of the bearing and rotor system.
Integral casting/forging parts: Key pressure bearing components such as pump casings and bearing seats are cast or forged with high-strength materials, which have good structural integrity and can withstand higher pressure and temperature fluctuations.
Innovative rotor dynamics and shaft seal technology
Optimized rotor design: The rotor undergoes rigorous dynamic analysis (finite element analysis) and high-speed dynamic balancing to ensure vibration values far below API standard requirements throughout the entire operating range and smooth operation.
Seal priority "shaft seal area: The shaft seal area has ample space and flexible design, optimized specifically to accommodate various complex API flushing schemes (Plan 11, 21, 23, 32, 52, 53, etc.). Easy installation of ChemPro mechanical seals or other branded containerized seals produced by Volkswagen.
Axial force balance: Through the careful design of impeller back blades, balance holes, or balance drums (in multi-stage design), residual axial forces are effectively managed to extend the life of thrust bearings.
Maintenance friendliness and interchangeability
Complete pull-out design: The standard API OH2 structure allows the entire bearing rotor seal assembly to be pulled out from the rear end as a whole without disassembling the inlet and outlet pipelines and pump casing, greatly simplifying maintenance work.
Centerline support: The pump casing is supported by a centerline to avoid misalignment caused by thermal expansion, making it particularly suitable for high temperature conditions (up to 400 ° C or above).
Standardization of components: Within the Volkswagen product family, many standard parts (such as bearings, seal chamber dimensions) have universality, which helps reduce spare parts inventory.
Efficient hydraulic performance
Advanced hydraulic model: Utilizing CFD fluid simulation and long-term accumulated hydraulic databases to optimize the impeller and volute, achieving a wide range of high efficiency zones while balancing design point efficiency and adaptability to operating conditions.
Replaceable wear parts: equipped with impeller mouth rings and shell wear rings, which can be replaced after wear to restore pump efficiency and reduce long-term operating energy consumption.
Wide selection of materials and configurations
We provide a full range of materials from carbon steel, 316 stainless steel, alloy 20, duplex/super duplex steel, Hastelloy alloy to titanium, covering various needs from clean water to strong corrosive media.
Multiple configuration options are available, such as foot installation, centerline installation, different steering, etc.
Integrated intelligent monitoring
It can be equipped with Volkswagen's Intellis status monitoring system, integrating vibration and temperature sensors to achieve real-time data acquisition, analysis, and warning, and support predictive maintenance.
2、 Main application industries
Due to its excellent reliability, adaptability to harsh operating conditions, and global technical service network, the Volkswagen OH2 pump dominates in the following key process industries:
Oil and Natural Gas
Upstream: offshore platform water injection pump, crude oil delivery pump.
Refining: It is the "main pump type" of refineries, widely used in high-temperature hot oil pumps, tower bottom pumps, feed pumps, reflux pumps and other units such as atmospheric and vacuum distillation, catalytic cracking, hydroprocessing, delayed coking, etc.
Petrochemicals: Heat medium pumps, quench oil pumps, and product pumps in ethylene cracking and aromatic hydrocarbon complex units.
Chemical and Petrochemical Industry
The production process pumps for various basic and fine chemicals transport high-temperature, high-pressure, toxic, flammable, explosive or high-value process fluids.
Energy and Electricity
Conventional thermal power: boiler feedwater pre pump, condensate polishing pump, hot water circulation pump.
Combined cycle power plant: feedwater pump and process pump for waste heat boiler system.
Oil and gas transportation and storage
Long distance pipelines: main pumps and booster pumps for crude oil, refined oil, and natural gas pipelines.
LNG receiving station: BOG (evaporated gas) recondenser pump, high-pressure export pump.
Other heavy industries
Coal chemical industry: key pumps for high-temperature and high-pressure processes such as coal gasification, coal to oil, and methanol to olefin production.
Pulp and paper: black liquor circulation pump, chemical addition pump.
summary
The Volkswagen OH2 pump is one of the global benchmark products for high-end process industry centrifugal pumps. The core technical feature lies in the reliability engineering design based on the API 610 standard, which has been verified by numerous rigorous working conditions worldwide. Compared with the Sulzer SCC series, both are highly consistent in their core design concepts (centerline support, rear pull-out), representing the highest level in the industry. The main differences may be reflected in the specific hydraulic model, local structural details, preference for sealing system integration (Volkswagen strongly promotes its own sealing), and the layout strategy of the global service network.
When choosing, the Volkswagen OH2 pump is the preferred choice for users who pursue ultimate operational reliability, strong global technical support, and hope to cooperate with suppliers with a full range of fluid product lines. It has particular advantages in factories that have signed long-term service agreements (LTSA) with Volkswagen.