Marelli OH2 end-suction, full centerline mounted, radial split, overhung horizontal single and double volute centrifugal pump

API-610 OH2 and ISO 13709 compliant for General Refinery Services centrifugal, single stage, full centerline mounted with high shaft rigidity for processes engineers requiring efficient high pressure and high temperature services

The Marelli SMK pump seres has a range of customized features to specific application requirements that process engineers require for upstream oil and gas, midstream, downstream refining, petrochemical and chemical processing.

  • Flows to 7,000 gpm (1,600 m³/hr)
  • Heads to 1,200 ft (256 m)
  • Suction Pressure 551 psi (38 bar)
  • Temperature Range -238 to 842°F (-150 to 450°C)

Precision engineered API/ISO 13709 process pumps meeting rigorous engineering requirements for heavy duty, high temperature applications while receding the total life cycle cost and improving mean time between repairs.



  • Hydrocracking
  • Topping
  • Gas condensate
  • HDS
  • Merox LPG
  • Amine
  • Sour water
  • Coking
  • Platforming


Crude oil and gas pipelines

Offshore and onshore oil and gas

Reverse osmosis


Proven to be reliable, efficient and long-lasting, Marelli OH2 pumps provide a number of operational benefits for process engineers and plant operators:

  • API 610 11th Edition/ISO 13709 full compliance for reliability and accountability
  • Suitable with 60 Hz and 50 kW motors
  • Higher efficiencies due to a design with tangential discharge and a wide variety of hydraulics to match exact duty points
  • Centerline mounted pump casing maintains alignment during operation and elevated temperatures
  • Low suction specific speed and low NPSH characteristics with a wide choice of impellers for optimum efficiency over a large operating range
  • Finned bearing housing to provide maximum heat dissipation under API 610 compliance
  • Isolation chamber at bearing housing with a thermal barrier among mechanical seal chamber and bearing housing
  • Deflection system with fins to improve cooling
  • Labyrinth bearing seals to avoid external contamination and maximize seal and lubrication life
  • Highly maintainable and replaceable wear rings to reduce overall life cycle costs
  • Socket welded flanged drains and vents as standard (gussets and bracing also available)
  • Choice of multiple impellers in each hydraulic pump casing for optimum efficiency over a wide operating range
  • A variety of instrumentation options are available for monitoring all key operating perimeters (temperature, pressure, vibrations and more)

US 60 Hz

  • Heads to                                                  1,200 ft
  • Flows to                                                   7,000 gpm
  • Standards                                               API 610 OH2
  • Maximum Motor Power                           938 HP
  • Temperature Range                                -238 to 842°F
  • Maximum Case Working Pressure          725 psi
  • Maximum Suction Pressure                     551 psi
  • Differential Head                                      1,200 ft
  • Maximum Viscosity                                   Consult Factory
  • Mounting Configuration                           Horizontal-end top
  • Seal Configurations                                 API 682
  • Available Flanges                                   300#, 600# ANSI FF/RF
  • Suction and Discharge Sizes               Up to 12″
  • API Plans                                                All API 682 Configurations

Metric 50 Hz

  • Heads to                                                  256 m
  • Flows to                                                   1,280 m3/hr
  • Standards                                                ISO 13709
  • Maximum Motor Power                           700 kW
  • Temperature Range                                -150 to 450°C
  • Maximum Case Working Pressure         50 bar
  • Maximum Suction Pressure                     38 bar
  • Differential Head                                      360 m
  • Maximum Viscosity                                 Consult factory
  • Mounting Configuration                           Horizontal-end top
  • Seal Configurations                                 API 682
  • Available Flanges                                300#, 600# ANSI FF/RF
  • Suction and Discharge Sizes            up to 30.48 cm
  • API Plans                                        All API 682 Configurations
Pressure CasingCarbon Steel (A216 WCB)12% CHR316 AUSDuplex
ImpellerCast IronCarbon Steel12% CHR316 AUS12% CHR316 AUSDuplex
Wear RingsCast Iron12% CHR HardenedHard-faced 316 AUS12% CHR HardenedHard-faced 316 AUSHard-faced Duplex
ShaftCarbon SteelAISI 4140316 AUS12% CHR316 AUSDuplex
Bearing HousingCarbon Steel (A216 WCB)
Base GasketAUS, Spiral Wound316 AUS Spiral WoundAUS, Spiral Wound316 AUS, Spiral WoundDuplex SS Spiral Wound

Customized High Temperature Features




Cooled mechanical seal chamber










External cooling for bearing housing with finned heat exchanger fed with inert fluid and/or water






Convection venting for bearing housing with a low noise fan placed at the rear in the coupling side

High Suction Pressure Options


Heavy duty bearing housings

Mechanical seals to meet safety and environmental requirements

Pump casing and seal chamber

Engineered bearings

Lubrication System

  • Purge ports with drain valve
  • Test gauges for condition analysis
  • Oil mist lubrication system with purge ports
  • Outboard oil mist system for assuring flow through each bearing

For Coking Services

  • Backwash system for wear rings and neck bushing
  • Specific coke crusher available

Baseplate Designs

  • Pre-grouted and non-grouted for all driver types
  • Special base designs to match oversize drivers, pump and turbines
  • Tailor made baseplates available
  • Skid mounting and oil field designs available

About Sundyne

Sundyne is the world leader in delivering low-flow, high-head, integrally geared centrifugal pumps and compressors, sealless magnetic drive pumps and diaphragm gas compressors. Sundyne’s precision-engineered, highly reliable, safe & efficient pumps and compressors are used in chemical, petrochemical, hydrocarbon, hydrogen, carbon capture, renewable fuels, power generation and industrial applications. Sundyne pumps and compressors are available in API, ANSI/ASME, ISO, and other industry compliant designs.