Product Overview
The SAP 012R belongs to the Sunfab SAP 012-108 DIN series of lightweight-casing axial piston pumps, featuring a bent-axis design with fixed displacement for demanding mobile hydraulic applications. The series covers a displacement range of 12–108 cm³/rev at a maximum working pressure of 400 bar. The mounting flange conforms to DIN 4-hole (ISO 7653D) standard, with shaft dimensions per DIN 5462 / ISO 14. The SAP DIN Optimised variant reduces operating noise by up to 6 dB compared to the standard SAP series, making it suitable for electric motor drive applications.
The SCP-034L belongs to the Sunfab SCP 012-130 ISO series of fixed-displacement axial piston pumps, with a nominal displacement of 34.2 cm³/rev, a maximum working pressure of 400 bar, and a maximum continuous speed of 2250 rpm. Weight is approximately 8.5 kg. This model is the direct upgrade replacement for the HAWE SC034LISO, with identical mounting dimensions and hydraulic parameters, widely used in concrete pump truck boom hydraulic systems and industrial hydraulic power units.
Both products are manufactured to exact Sunfab original specifications, delivering true drop-in interchangeability — identical mounting flange, shaft specification, port positions, and displacement rating. Every unit undergoes 100% simulated operating condition testing before shipment, with volumetric efficiency verified under rated pressure.
Technical Specifications
SAP 012R-N-DL4-L35-SOS-000
Model: SAP 012R-N-DL4-L35-SOS-000 (Item Code: 1253204)
Series: SAP 012-108 DIN
Displacement: 12.6 cm³/rev (0.77 in³/rev)
Max Continuous Working Pressure: 400 bar (5800 PSI)
Max Continuous Speed: 2300 rpm
Rotation Direction: Right hand (clockwise, viewed from shaft end)
Mounting Flange: DIN 4-hole (ISO 7653D)
Shaft Specification: DIN 5462 / ISO 14
Sealing Type: Nitrile
Connection Cover: S0 Standard 40°
Theoretical Flow at 2300 rpm: Approx. 29 L/min
Max Theoretical Torque: Approx. 6.7 N·m
Pump Type: Bent axis, fixed displacement, single flow
Weight: Approx. 4.5 kg (depending on configuration)
SCP-034L-N-142-W30-SOS-100
Model: SCP-034L-N-142-W30-SOS-100
Series: SCP 012-130 ISO / SAE
Displacement: 34.2 cm³/rev (2.09 in³/rev)
Max Continuous Working Pressure: 400 bar (5800 PSI)
Max Continuous Speed: 2250 rpm
Rotation Direction: Left hand (counterclockwise, viewed from shaft end)
Mounting Flange: SAE B 4-hole / ISO standard
Shaft Specification: SAE B splined shaft (13-tooth)
Sealing Type: Nitrile
Control Type: Fixed displacement (no variable control)
Weight: Approx. 8.5 kg
Pump Type: Bent axis, fixed displacement, single flow
System Type: Open-circuit hydraulic system
Key Technical Advantages
1. High Volumetric Efficiency from Bent-Axis Design
Both SAP and SCP series utilize a bent-axis configuration in which pistons directly drive the cylinder barrel, achieving higher mechanical efficiency than swashplate designs. Piston-to-bore clearances are held to micron-level tolerances through precision grinding, and valve plate surfaces receive mirror-finish lapping to minimize internal leakage. This architecture maintains stable volumetric efficiency even at 400 bar working pressure, suitable for heavy-duty continuous operation.
2. Lightweight Casing & Compact Installation Envelope
The SAP 012-108 DIN series employs a lightweight casing design that covers 12–108 cm³/rev displacement within a compact installation envelope. The pump can be mounted directly on a power take-off (PTO) or on a frame bracket via an intermediate shaft. Mounting flanges and shafts conform to DIN / ISO standards for broad compatibility.
3. Low-Noise Operation
The SAP DIN Optimised variant optimizes internal flow paths and port timing to reduce operating noise by up to 6 dB compared to the standard SAP series, while maintaining high-speed performance — particularly suitable for electric motor drive and noise-sensitive indoor or vehicle applications.
4. Wide Speed Range with Stable Output
The SAP 012R delivers stable flow output across 500–2300 rpm, while the SCP-034L supports continuous operation up to 2250 rpm. The bent-axis architecture maintains smooth operating characteristics throughout the speed range with excellent flow linearity, meeting the demands of variable-speed mobile machinery.
5. Material & Process Reliability
Core friction pairs use high-strength bearing steel, heat-treated and precision-ground for superior wear resistance. All contact surfaces are fitted with O-ring seals, and the shaft end employs a double-seal configuration to prevent oil leakage from the pump and power take-off interface. Housing materials receive corrosion-resistant treatment for outdoor and harsh-environment operation.
Application Areas
Concrete Pump Trucks: Boom hydraulic system drive — SCP-034L is a direct upgrade replacement for HAWE SC034LISO, compatible with SANY, Zoomlion, and other mainstream pump truck brands
Construction Machinery: Excavator hydraulic systems, loader implement drives, road roller vibration circuits
Commercial Vehicles: Tipper truck hydraulic lift systems, street sweepers, garbage compactor hydraulic power units
Agricultural Equipment: Tractor hydraulic hitch systems, combine harvester travel and implement drives
Industrial Hydraulic Power Units: Die-casting machines, injection molding machines, machine tool hydraulic systems
Expert Maintenance Tips
1. Installation Alignment Requirements
Bent-axis piston pumps demand high alignment precision between the drive shaft and pump shaft. During installation, ensure coupling concentricity deviation does not exceed 0.05 mm and angular deviation does not exceed 0.5°. For splined shaft connections, apply appropriate grease to the spline surface to prevent dry-friction wear.
2. Mandatory Case Pre-Fill
The pump housing must be filled with clean hydraulic fluid before initial startup. Starting a bent-axis pump dry will rapidly damage the valve plate and piston/cylinder interface. Fill through the highest case port with fluid filtered to ≤10 μm until oil overflows.
3. Suction Line Requirements
Suction line diameter must accommodate the pump’s flow demand at maximum speed. At 2300 rpm, the SAP 012R theoretical flow is approximately 29 L/min — a minimum suction line ID of 25 mm is recommended. At 2250 rpm, the SCP-034L flow is approximately 77 L/min — a minimum suction line ID of 32 mm is recommended. The suction inlet should sit at least 100 mm below the reservoir oil level.
4. Fluid Cleanliness Control
Maintain hydraulic system cleanliness at NAS 9 or ISO 18/16/13 or better. The valve plate in bent-axis piston pumps is sensitive to particulate contamination. Install a 10 μm nominal filtration element in the suction line; replace after the first 200 hours, then inspect or replace every 500 hours.
5. Periodic Shaft Seal Inspection
The shaft-end double-seal configuration may age or wear over extended service. Inspect for oil seepage at the shaft end every 2000 hours. When replacing seals, simultaneously inspect the shaft spline for wear — if spline teeth show visible stepping or pitting, replace the shaft or the complete pump.
