Piston pump
HENGYUHANG Axial Piston Variable Displacement Pump HYH2VK Series
Engineered with a heavy-duty bent-axis rotary group, corrosion-protected surface treatment, and a double shaft sealing system with integrated buffer fluid monitoring ports, the HENGYUHANG HYH2VK series variable displacement axial piston metering pump delivers microscopic volumetric accuracy and pulse-free stoichiometric dosing for polyurethane raw materials (polyol and isocyanate) at a nominal continuous operating pressure of 250 bar and maximum peak pressure of 315 bar (4,550 psi / 31.5 MPa).
| Applications
Designed specifically for high-pressure reaction injection molding (RIM) machinery, polyurethane foam processing lines, continuous sandwich insulation panel lamination, automotive interior acoustic foaming units, and precision chemical dosing skids, this specialized bent-axis variable pump features ISO 3019-2 4-bolt mounting flanges, DIN 6885 cylindrical keyed drive shafts, and manual handwheel control (MA) with an integrated precision measuring scale, delivering seamless 1:1 OEM drop-in interchangeability for Bosch Rexroth A2VK series (A2VK 12, A2VK 28, A2VK 55, A2VK 107) open-circuit installations.
| Key Technical Specifications
Product Model: Hengyuhang Axial Piston Variable Displacement Pump HYH2VK Series (HYH2VKO Open Circuit)
Brand Replacement: Bosch Rexroth A2VK Series (Sizes 12, 28, 55, 107; Series 1 and 4) OEM or as requested.
Displacement: 4 standardized displacement sizes (Size 12: 11.6 cm³/rev, Size 28: 28.1 cm³/rev, Size 55: 54.8 cm³/rev, Size 107: 107.0 cm³/rev; infinitely adjustable down to 0 cm³/rev)
Rotation Direction: Clockwise (R, standard), counter-clockwise (L, option) (viewed from drive shaft end)
Speed Range: Rated for standard motor operating speeds of 735, 970, 1,450, and 1,800 r/min (delivering theoretical flows up to 150.5 L/min at 1,450 r/min and 186.8 L/min at 1,800 r/min)
Peak Pressure: Nominal working pressure 250 bar (3,600 psi); Maximum peak pressure 315 bar (4,550 psi / 31.5 MPa)
- Description
- Tecspecs
- Brand & Reference
- Download HENGYUHANG HYH2VK Axial Piston Variable Displacement Pump PDF
- Send an Inquiry
| Overview of HENGYUHANG HYH2VK Series
The HENGYUHANG HYH2VK Series is an industrial-grade, heavy-duty axial piston variable displacement pump built with a proven bent-axis rotary group, engineered specifically for pumping, metering, and mixing chemically aggressive polyurethane components, including polyols and isocyanates (MDI/TDI). Manufactured across four standardized frame sizes—Size 12 (11.6 cm³/rev), Size 28 (28.1 cm³/rev), Size 55 (54.8 cm³/rev), and Size 107 (107.0 cm³/rev)—the pump provides continuous, stepless displacement adjustment from maximum volume down to zero delivery (Vg min = 0), empowering polyurethane processing plants to maintain exacting mixing ratios with outstanding batch repeatability.
Constructed with special surface-treated ductile cast iron housings for enhanced corrosion resistance (SO2 specification equivalent), the HYH2VK Series features optimized material pairings and specialized sealing elements specifically compatible with reactive polyols and abrasive isocyanates. A double shaft seal assembly with dedicated buffer fluid ports (U1 to U4) isolates the chemical process fluid from the atmosphere, providing continuous barrier protection against crystallization, moisture ingress, or environmental contamination. Configured in the open-circuit design (HYH2VKO) where the pump housing connects internally to the suction chamber (eliminating the requirement for an external case drain line back to the reservoir, with permissible suction filling pressures from 1 to 10 bar abs), the HYH2VK Series delivers direct 1:1 dimensional and hydraulic interchangeability for Bosch Rexroth A2VK Series 1 & 4 pumps, ensuring rapid field replacement without pipework or mounting modifications.
| Dimension of HENGYUHANG HYH2VK Series
| Interface Data Needed with the Drawing (Sizes 12, 28, 55, 107)
| Interface Parameter | Size 12 (HYH2VK 12) | Size 28 (HYH2VK 28) | Size 55 (HYH2VK 55) | Size 107 (HYH2VK 107) | Engineering Verification & Assembly Notes |
|---|---|---|---|---|---|
| Mounting Flange Standard | ISO 3019-2 4-bolt (80-4 pattern) | ISO 3019-2 4-bolt (100-4 pattern) | ISO 3019-2 4-bolt (125-4 pattern) | ISO 3019-2 4-bolt (160-4 pattern) | Identical mounting pattern with Bosch Rexroth A2VK & A7VK |
| Pilot Spigot Diameter | Ø 80 mm (h8/h9) | Ø 100 mm (h8/h9) | Ø 125 mm (h8/h9) | Ø 160 mm (h9) | Precision centering spigot for pump bell housing alignment |
| Bolt Pitch Circle Diameter | Ø 100 mm | Ø 125 mm | Ø 160 mm | Ø 200 mm | Symmetrical 4-bolt circular mounting pattern (45° offset) |
| Flange Fixing Thread | 4 × M8 female thread | 4 × M10 female thread | 4 × M16 female thread | 4 × M16 female thread | Fastener engagement depth according to DIN standard |
| Drive Shaft Standard | Cylindrical keyed P (DIN 6885) | Cylindrical keyed P (DIN 6885) | Cylindrical keyed P (DIN 6885) | Cylindrical keyed P (DIN 6885) | Parallel keyed drive shaft with end centering thread DIN 332 |
| Shaft Diameter & Fit | Ø 20 mm | Ø 25 mm | Ø 30 mm | Ø 40 mm | Precision cylindrical ground shaft with chamfered lead-in |
| Fitted Drive Key | A6 × 6 × 25.5 (DIN 6885) | AS8 × 7 × 40 (DIN 6885) | AS8 × 7 × 43 (DIN 6885) | AS12 × 8 × 63 (DIN 6885) | Key width 6 mm / 8 mm / 8 mm / 12 mm |
| Shaft Centering Thread | M6 × 1 (thread depth 10 mm) | M8 × 1.25 (thread depth 11 mm) | M10 × 1.5 (depth 12.5 mm) | M12 × 1.75 (depth 15 mm) | Tapped center bore according to DIN 332 / DIN 13 |
| Service Line Port A / B | DIN 3852: M22 × 1.5 (Max 210 N·m) | DIN 3852: M27 × 2 (Max 330 N·m) | DIN 3852: M33 × 2 (Max 540 N·m) | DIN 3852: M42 × 2 (Max 720 N·m) | High-pressure outlet port (p N = 250 bar, p max = 315 bar) |
| Suction Port S (Inlet / Filling) | DIN ISO 228: G 1 1/4 (Max 720 N·m) | DIN ISO 228: G 1 1/2 (Max 960 N·m) | DIN ISO 228: G 2 (Max 1200 N·m) | DIN ISO 228: G 2 1/2 (Max 2000 N·m) | Suction filling port inlet side (p min = 1 bar, p max = 10 bar abs) |
| Leakage Ports T1, T2 | DIN 3852: M12 × 1.5 (Max 50 N·m) | DIN 3852: M16 × 1.5 (Max 100 N·m) | DIN 3852: M18 × 1.5 (Max 140 N·m) | DIN 3852: M18 × 1.5 (Max 140 N·m) | Plugged on delivery; housing connected internally to suction S |
| Air Bleed Port R | DIN 3852: M12 × 1.5 (Max 50 N·m) | DIN 3852: M12 × 1.5 (Max 50 N·m) | DIN 3852: M12 × 1.5 (Max 50 N·m) | DIN 3852: M12 × 1.5 (Max 50 N·m) | Air bleeding port; plugged in normal operation |
| Buffer Fluid Ports U1 to U4 | DIN 3852: M10 × 1 (depth 8 mm, 30 N·m) | DIN 3852: M10 × 1 (depth 8 mm, 30 N·m) | DIN 3852: M10 × 1 (depth 8 mm, 30 N·m) | DIN 3852: M10 × 1 (depth 8 mm, 30 N·m) | Buffer fluid monitoring chamber for double shaft seal |
| Pressure Limiting Valve Port B1 (Option) | DIN 3852: M22 × 1.5 (depth 14 mm, 210 N·m) | DIN 3852: M27 × 2 (depth 16 mm, 330 N·m) | DIN 3852: M33 × 2 (depth 18 mm, 540 N·m) | DIN 3852: M42 × 2 (depth 20 mm, 720 N·m) | Service outlet line on attached pressure relief block |
| Relief Return Port T3 (Option) | DIN 3852: M18 × 1.5 (depth 12 mm, 140 N·m) | DIN 3852: M22 × 1.5 (depth 14 mm, 210 N·m) | DIN 3852: M27 × 2 (depth 16 mm, 330 N·m) | DIN 3852: M33 × 2 (depth 20 mm, 540 N·m) | Tank return port on attached pressure relief valve |
| Pump Installation Specifications HENGYUHANG HYH2VK Series
| Comprehensive Ordering Code Structure (Aligned with RE 94001 A2VK Open Circuit Program)
Code structure — reference: HYH2VK−Size−MA−O−Rotation−Series−G−Valve−P−E−Handwheel−SO2
| Position | Code Element | Specification Options | Description & Functional Details |
|---|---|---|---|
| 01 | Axial Piston Unit | HYH2VK | Variable displacement axial piston pump for pumping and metering plastic/polyurethane components |
| 02 | Displacement Size | 12, 28, 55, 107 | Size 12: 11.6 cm³/rev (0.71 in³/rev); Size 28: 28.1 cm³/rev (1.71 in³/rev); Size 55: 54.8 cm³/rev (3.34 in³/rev); Size 107: 107.0 cm³/rev (6.53 in³/rev) |
| 03 | Control Device | MA | Manual adjustment via handwheel with self-locking threaded spindle and integral precision measuring scale |
| 04 | Operating Mode | O | Open-circuit design (housing internally connected to suction chamber S; no external leakage drain line required) |
| 05 | Direction of Rotation | R, L | R = Clockwise rotation (standard, looking onto drive shaft); L = Anti-clockwise rotation (option, looking onto drive shaft) |
| 06 | Series | 4, 1 | 4 = Series 4 (dedicated for Size 12); 1 = Series 1 (standard for Sizes 28, 55, 107) |
| 07 | Model Construction | G | Enclosed pump execution |
| 08 | Valve Attachment | 0, 1 | 0 = Without attached pressure limiting valve (standard); 1 = With attached high-pressure limiting valve block |
| 09 | Drive Shaft | P | Cylindrical parallel shaft with key according to DIN 6885 |
| 10 | Swivel Angle Mode | E | One-sided displacement adjustment |
| 11 | Handwheel Assembly Version | 1, 2 | 1 = Handwheel mounted on left side (looking onto drive shaft); 2 = Handwheel mounted on right side (looking onto drive shaft) |
| 12 | Corrosion Protection | SO2 | Special surface treatment for enhanced corrosion protection against chemical media |
| Reading Your Replacement Code
| Target Bosch Rexroth Part Code | HENGYUHANG Replacement Code | Direct Interchange Verification Notes |
|---|---|---|
| A2VK 12 MA O R 4 G 0 P E 1 - SO2 | HYH2VK-12-MA-O-R-4-G-0-P-E-1-SO2 | Direct 1:1 drop-in: Size 12, 11.6 cm³/rev, open circuit, CW rotation, Series 4, without valve, keyed shaft P, handwheel left, SO2 corrosion protection |
| A2VK 28 MA O R 1 G 0 P E 1 - SO2 | HYH2VK-28-MA-O-R-1-G-0-P-E-1-SO2 | Direct 1:1 drop-in: Size 28, 28.1 cm³/rev, open circuit, CW rotation, Series 1, without valve, keyed shaft P, handwheel left, SO2 corrosion protection |
| A2VK 55 MA O R 1 G 0 P E 1 - SO2 | HYH2VK-55-MA-O-R-1-G-0-P-E-1-SO2 | Direct 1:1 drop-in: Size 55, 54.8 cm³/rev, open circuit, CW rotation, Series 1, without valve, keyed shaft P, handwheel left, SO2 corrosion protection |
| A2VK 107 MA O R 1 G 0 P E 1 - SO2 | HYH2VK-107-MA-O-R-1-G-0-P-E-1-SO2 | Direct 1:1 drop-in: Size 107, 107.0 cm³/rev, open circuit, CW rotation, Series 1, without valve, keyed shaft P, handwheel left, SO2 corrosion protection |
| A2VK 28 MA O L 1 G 0 P E 1 - SO2 | HYH2VK-28-MA-O-L-1-G-0-P-E-1-SO2 | Direct 1:1 drop-in: Size 28, open circuit, anti-clockwise rotation (L), Series 1, without valve, keyed shaft P, handwheel left, SO2 corrosion protection |
| A2VK 28 MA O R 1 G 1 P E 1 - SO2 | HYH2VK-28-MA-O-R-1-G-1-P-E-1-SO2 | Direct 1:1 drop-in: Size 28, open circuit, CW rotation, Series 1, with attached direct-operated pressure limiting valve, keyed shaft P, handwheel left |
| Techspecs of HENGYUHANG HYH2VK Series
| 4.1 Standard Unit Technical Data (Sizes 12, 28, 55, 107 Aligned with RE 94001)
| Parameter / Technical Specification | Symbol | Unit | Size 12 | Size 28 | Size 55 | Size 107 | Engineering Verification Notes |
|---|---|---|---|---|---|---|---|
| Geometric Displacement (Maximum) | Vg max | cm³/rev | 11.6 | 28.1 | 54.8 | 107.0 | Full stroke displacement rating per shaft revolution |
| Geometric Displacement (Minimum) | Vg min | cm³/rev | 0 | 0 | 0 | 0 | Steplessly adjustable down to complete zero delivery |
| Flow Delivery at n = 735 r/min | qv 735 | L/min | 8.3 | 20.0 | 39.1 | 76.3 | Calculated at Vg max (includes 3% loss of displacement) |
| Flow Delivery at n = 970 r/min | qv 970 | L/min | 10.9 | 26.4 | 51.6 | 100.7 | Calculated at Vg max (includes 3% loss of displacement) |
| Flow Delivery at n = 1,450 r/min | qv 1450 | L/min | 16.3 | 39.5 | 77.1 | 150.5 | Standard 50 Hz electric motor speed rating (4.3 to 39.8 gpm) |
| Flow Delivery at n = 1,800 r/min | qv 1800 | L/min | 20.3 | 49.1 | 95.7 | 186.8 | Standard 60 Hz electric motor speed rating (5.4 to 49.3 gpm) |
| Drive Power at n = 735 r/min (Δp = 250 bar) | P 735 | kW | 3.4 | 8.3 | 16.3 | 31.8 | Power delivery at low-speed operating point (4.6 to 42.6 HP) |
| Drive Power at n = 970 r/min (Δp = 250 bar) | P 970 | kW | 4.5 | 11.0 | 21.5 | 41.9 | Power delivery at intermediate operating point (6.0 to 56.2 HP) |
| Drive Power at n = 1,450 r/min (Δp = 250 bar) | P 1450 | kW | 6.8 | 16.5 | 32.1 | 62.7 | Power required at 1,450 rpm duty cycle (9.1 to 84.1 HP) |
| Drive Power at n = 1,800 r/min (Δp = 250 bar) | P 1800 | kW | 8.4 | 20.4 | 39.9 | 77.8 | Power required at 1,800 rpm duty cycle (11.3 to 104.3 HP) |
| Handwheel Adjustment Turns (Vg 0 → Vg max) | Us | turns | 10.6 | 12.7 | 16.0 | 13.4 | Number of handwheel rotations across full stroke range |
| Maximum Handwheel Adjustment Force | F max | N | 70 | 70 | 80 | 120 | Actuation force on handwheel perimeter rim |
| Mass (Approximate Dry Pump with Control Unit) | m | kg | 19.0 | 36.0 | 64.0 | 117.0 | Heavy-duty rigid casing mass (41.9 to 257.9 lbs) |
| 4.2 Working Pressure Range & Differential Operating Limits (from RE 94001)
| Pressure Parameter | Symbol | Metric Rating | US Imperial Rating | Operational Definition & System Boundaries |
|---|---|---|---|---|
| Nominal Working Pressure | p N | 250 bar | 3,600 psi | Maximum continuous operating design pressure at service port A or B |
| Maximum Peak Pressure | p max | 315 bar | 4,550 psi | Maximum permissible peak operating pressure according to DIN 24312 |
| Minimum Filling Pressure (Open Circuit Port S) | p min abs | 1 bar absolute | 14.5 psi abs | Minimum absolute inlet pressure required to ensure complete pump filling |
| Maximum Filling Pressure (Open Circuit Port S) | p max abs | 10 bar absolute | 145 psi abs | Maximum allowable positive inlet supercharging pressure |
| Maximum Leakage Fluid Pressure | p L max | 10 bar absolute | 145 psi abs | Maximum permissible pressure in pump casing acting on shaft seal |
| Buffer Fluid Port Pressure (Ports U1 – U4) | p buffer | Max 10 bar abs | Max 145 psi abs | Monitored barrier fluid chamber to ensure complete shaft sealing |
| 4.3 General Operating Conditions & Fluid Compatibility (Aligned with RE 94001)
| Parameter | Permissible Operating Range | Optimal Target Condition | Engineering Compliance Notes |
|---|---|---|---|
| Approved Process Media | Polyurethane components: Polyols & Isocyanates (MDI/TDI) | Pure, degassed chemical raw materials | Materials and sealing elements specifically paired for polyol and isocyanate |
| Operating Viscosity Range | ν = 1 to 2,000 mm²/s (cSt) | Optimized for process fluid viscosity | Inquire with engineering if higher viscosity values are required |
| Operating Temperature Range | t = 10 °C to 50 °C (optimum range) | +20 °C to +40 °C (+68 °F to +104 °F) | Maximum working temperature t max = 80 °C (176 °F); ≤ 5 K over leakage fluid |
| Filtration Requirement | Absolute filtration rating η abs ≤ 125 μm | In-line high-efficiency chemical filter | The finer the filter, the longer the service life of the axial piston unit |
| Sealing System Construction | Double shaft seals with buffer fluid ports | Monitored buffer fluid barrier | U1 to U4 ports guarantee safe operation and prevent environmental escape |
| Preferred Mounting Position | Horizontal drive shaft orientation (recommended) | Drive shaft horizontal | Adjusting spindle installed within -30 ° to +30 ° of horizontal for scale visibility |
Advantages
Proven Bent-Axis Metering Precision
The time-tested bent-axis rotary group with axial tapered pistons delivers exceptionally high volumetric efficiency, outstanding reproducibility, and minimal hydraulic pulsation across the entire operating pressure range.
Double Shaft Sealing with Buffer Fluid Chamber
Features dual specialized shaft seal elements with integrated buffer fluid ports (U₁ to U₄), creating an isolated barrier chamber that prevents chemical leakage, air ingress, and moisture-induced isocyanate crystallization.
Robust Manual Adjustment (MA) with Integrated Scale
Equipped with a heavy-duty handwheel driving a self-locking threaded spindle, featuring an integral precision measuring scale for microscopic stroke reproducibility and zero-drift volumetric setting.
Corrosion-Protected Casing (SO2 Execution)
Manufactured with specialized surface treatment and protective material pairings, providing robust resistance against chemically aggressive polyols, amine catalysts, isocyanates, and flushing solvents.
High Permissible Inlet Supercharging
Supports suction filling pressures up to 10 bar absolute, ensuring complete cylinder filling and cavitation-free performance even when pumping highly viscous polyols.
Streamlined Open-Circuit Installation
Open-circuit design connects the internal housing space directly to the suction port S, eliminating external leakage drain lines back to the reservoir and significantly simplifying machine pipework.
Reference
Displacement & Control Configuration Matrix
Available Displacement Sizes:
HYH2VK 12 (Series 4): Nominal displacement 11.6 cm³/rev (0.71 in³/rev); delivery 16.3 L/min @ 1,450 rpm, 20.3 L/min @ 1,800 rpm; dry mass 19 kg; handwheel turns Us=10.6.
HYH2VK 28 (Series 1): Nominal displacement 28.1 cm³/rev (1.71 in³/rev); delivery 39.5 L/min @ 1,450 rpm, 49.1 L/min @ 1,800 rpm; dry mass 36 kg; handwheel turns Us=12.7.
HYH2VK 55 (Series 1): Nominal displacement 54.8 cm³/rev (3.34 in³/rev); delivery 77.1 L/min @ 1,450 rpm, 95.7 L/min @ 1,800 rpm; dry mass 64 kg; handwheel turns Us=16.0.
HYH2VK 107 (Series 1): Nominal displacement 107.0 cm³/rev (6.53 in³/rev); delivery 150.5 L/min @ 1,450 rpm, 186.8 L/min @ 1,800 rpm; dry mass 117 kg; handwheel turns Us=13.4.
Control Architecture:
MA Manual Adjustment: Self-locking threaded spindle with integral optical position scale; handwheel mountable on left (1) or right (2) side; adjustment forces from 70 N to 120 N.
Optional Attached Pressure Limiting Valve: Integrated high-pressure relief valve block mounted on service port with auxiliary outlet B1 and return port T3, providing direct circuit overpressure protection.
Target Brand Interchangeability Matrix
The HENGYUHANG HYH2VK Series provides verified 1:1 direct mechanical and hydraulic interchangeability across the full Bosch Rexroth A2VK product family:
Bosch Rexroth A2VK 12 MA O R 4 G 0 P E 1 - SO2 → HYH2VK-12-MA-O-R-4-G-0-P-E-1-SO2 (Size 12, open circuit, clockwise)
Bosch Rexroth A2VK 28 MA O R 1 G 0 P E 1 - SO2 → HYH2VK-28-MA-O-R-1-G-0-P-E-1-SO2 (Size 28, open circuit, clockwise)
Bosch Rexroth A2VK 55 MA O R 1 G 0 P E 1 - SO2 → HYH2VK-55-MA-O-R-1-G-0-P-E-1-SO2 (Size 55, open circuit, clockwise)
Bosch Rexroth A2VK 107 MA O R 1 G 0 P E 1 - SO2 → HYH2VK-107-MA-O-R-1-G-0-P-E-1-SO2 (Size 107, open circuit, clockwise)
Bosch Rexroth A2VK 12 MA O L 4 G 0 P E 1 - SO2 → HYH2VK-12-MA-O-L-4-G-0-P-E-1-SO2 (Size 12, open circuit, anti-clockwise)
Bosch Rexroth A2VK 28 MA O L 1 G 0 P E 1 - SO2 → HYH2VK-28-MA-O-L-1-G-0-P-E-1-SO2 (Size 28, open circuit, anti-clockwise)
Bosch Rexroth A2VK 55 MA O L 1 G 0 P E 1 - SO2 → HYH2VK-55-MA-O-L-1-G-0-P-E-1-SO2 (Size 55, open circuit, anti-clockwise)
Bosch Rexroth A2VK 107 MA O L 1 G 0 P E 1 - SO2 → HYH2VK-107-MA-O-L-1-G-0-P-E-1-SO2 (Size 107, open circuit, anti-clockwise)
Attached Valve Execution: Direct drop-in for Rexroth valve-equipped models A2VK...G 1 P E... with integral pressure limiting valve block.
Brand Replacement
HENGYUHANG manufactures the HYH2VK Series as a precision-engineered, direct-replacement solution for classic OEM chemical metering pumps in polyurethane processing machinery:
Bosch Rexroth: Full 1:1 interchangeability for A2VK Series (A2VK 12, A2VK 28, A2VK 55, A2VK 107; Series 1 and Series 4 open-circuit programs).
Polyurethane OEM Machinery Compatibility: Fully compatible with metering and foaming equipment from KraussMaffei, Hennecke, Cannon, Tartarini, Saip, Rimaster, and OMS Group.
Component Interchangeability: Shaft centerlines, 4-bolt ISO 3019-2 mounting flanges, DIN 6885 cylindrical keyed drive shafts, and threaded port geometries align identically, requiring no modification to existing machine mounting plates, drive couplings, or pipework.
Applications
High-Pressure Reaction Injection Molding (RIM): Precision metering of polyol and isocyanate streams into high-pressure impingement mixing heads at pressures up to 250 bar.
Automotive Interior Component Foaming: Polyurethane dosing for automotive seating cushions, instrument panel soft-trim, steering wheels, acoustic sound-deadening insulation, and headrests.
Rigid Polyurethane Thermal Insulation Panels: Continuous double-belt lamination lines for building insulation panels, cold storage sandwich panels, and commercial refrigeration cabinets.
Flexible Slabstock Foam Production: Continuous foaming lines for furniture mattresses, upholstered seating, and packaging foams requiring precise, pulse-free component delivery.
Adhesive, Sealant & Elastomer Dispensing: High-accuracy stoichiometric metering of two-component polyurethane adhesives, structural sealants, potting resins, and microcellular elastomers.
Chemical Dosing & Pilot Plant Test Skids: Pilot-scale chemical processing and research laboratory test rigs requiring infinitely adjustable, repeatable variable displacement under medium pressure.
Package & Shipping
| Packaging Construction | Heavy-duty multi-layer export-grade solid wooden case with reinforced internal cradle and shock-absorbing high-density polyethylene foam inserts. |
|---|---|
| Corrosion Protection | Internal flushing with moisture-free chemical test oil; all exposed precision ground surfaces (drive shaft, mounting pilot) treated with VCI anti-corrosion barrier and vacuum-sealed in heavy-gauge barrier foil. |
| Port & Shaft Protection | Heavy-duty threaded steel and plastic protective plugs installed on all service, suction, leakage, bleed, and buffer fluid ports; drive shaft fitted with heavy-duty protective composite sleeve. |
| Package Dimensions (Approx.) | Size 12: 420 × 320 × 300 mm; Size 28: 500 × 380 × 340 mm; Size 55: 580 × 420 × 380 mm; Size 107: 680 × 480 × 450 mm. |
| Gross Shipping Weight | Size 12: approx. 24.0 kg; Size 28: approx. 43.0 kg; Size 55: approx. 74.0 kg; Size 107: approx. 132.0 kg (inclusive of export crating). |
| Standard Lead Time | Standard displacement configurations dispatched within 48–72 hours from inventory; custom-engineered or special-mount units completed in 10–15 business days. |
| Global Shipping Options | Air Express (DHL, FedEx, UPS, TNT), Air Cargo door-to-airport, Sea Freight FCL/LCL, and multimodal international rail transport with DDP/DAP terms available. |
| Quality Documentation | Complete factory inspection test certificate, volumetric efficiency test record, hydrostatic pressure test report, and CE declaration of conformity included in each shipment. |
Why Choose Hengyuhang?
Direct Factory Precision Manufacturing & CNC Excellence: Manufactured in our state-of-the-art hydraulic facility utilizing German and Japanese 5-axis machining centers, precision CNC cylindrical grinding machines, and sub-micron honing systems, ensuring rotary group dimensional tolerances within ±0.002 mm and surface roughness Ra < 0.2 μm.
100% Full-Cycle Multi-Parameter Factory Inspection: Every HYH2VK pump undergoes 100% automated test bench calibration prior to shipment, verifying volumetric efficiency (>93%), continuous and peak pressure holding (250/315 bar), internal case leakage, mechanical torque, noise spectrum, and zero-leakage buffer fluid chamber sealing.
Seamless 1:1 OEM Drop-In Interchangeability: Engineered to strict international ISO 3019-2 and DIN standards, guaranteeing direct, plug-and-play mechanical and hydraulic interchangeability with Bosch Rexroth A2VK Series (A2VK 12, A2VK 28, A2VK 55, A2VK 107) open-circuit pumps without piping or mounting modifications.
Flexible Engineering Customization & Rapid Prototyping: Supported by senior fluid power and chemical machinery engineers, we provide tailored solutions including specialized corrosion-resistant coatings, custom flange patterns, alternative seal materials (EPDM, FFKM), integrated relief valve calibrations, and rapid prototype delivery with low MOQ requirements.
Robust Supply Chain, Extensive Inventory & Fast Global Dispatch: Extensive inventory of finished assemblies, ductile iron castings, bent-axis rotary groups, shafts, and seal kits ensures standard units ship within 48 to 72 hours, backed by reliable worldwide express logistics (DHL, FedEx, UPS) and door-to-door DDP services.
12-Month Comprehensive Warranty & Lifetime Technical Support: All products are covered by a full 12-month comprehensive warranty and backed by lifetime engineering assistance, including complimentary CAD model verification, installation troubleshooting, and 24-hour rapid technical customer response.
HENGYUHANG Axial Piston Variable Displacement Metering Pump HYH2VK Series (Variable Axial Piston Pump for Pumping and Metering Polyurethane Components, 11.60~107.00 cm³/rev) is a heavy-duty, high-precision bent-axis axial piston variable displacement pump engineered specifically for the continuous pumping, dosing, and high-pressure chemical metering of polyurethane reaction injection molding (RIM) liquid components, including polyol and isocyanate. Designed as a 100% direct dimensional, hydraulic, and functional custom drop-in replacement for the global industry standard Bosch Rexroth A2VK Series (A2VK 12 Series 4, A2VK 28 Series 1, A2VK 55 Series 1, and A2VK 107 Series 1), the HYH2VK Series features a proven bent-axis rotary group with tapered piston technology that delivers exceptional volumetric efficiency, ultra-low flow pulsation, and outstanding shot-to-shot metering reproducibility. Operating at continuous nominal working pressures (p_nom) of 250 bar (3,625 psi / 25 MPa) and peak operating pressures (p_max) up to 315 bar (4,568 psi / 31.5 MPa), this pump series is manufactured in two dedicated hydraulic circuit architectures: the Open Circuit design (HYH2VKO), where the pump housing communicates directly with suction port S to eliminate external case drain piping, and the Closed Circuit design (HYH2VKG), which features an isolated casing space for high-pressure transfer lines with independent case leakage ports (T1/T2). Constructed with robust ISO metric 4-bolt mounting flanges (centering pilot Ø80 mm to Ø160 mm), cylindrical keyed drive shafts to DIN 6885 (Ø20 mm to Ø40 mm), a rugged manual handwheel control unit (MA control) equipped with an integral high-resolution mechanical measuring scale, and specialized double radial shaft seals with integrated buffer fluid flushing ports (U1~U4) for crystallization prevention and zero-leakage environmental protection, the HYH2VK Series ensures seamless drop-in field substitution without hydraulic piping alterations or mounting bracket modifications.
| Applications
The HYH2VK Series axial piston variable metering pump is purpose-built for chemical process equipment and continuous polyurethane reaction lines requiring micro-adjustable flow rates, high volumetric accuracy, and complete compatibility with aggressive chemical media:
Polyurethane Reaction Injection Molding (RIM): Accurately doses polyol, isocyanate, and blowing agents into high-pressure mixing heads at pressures up to 250 bar, maintaining exact stoichiometric mixing ratios for structural RIM parts.
Rigid Polyurethane Foam Insulation Panels: Powers continuous laminating double-belt production lines for cold-room polyurethane sandwich panels, exterior wall building insulation, and pre-insulated district heating pipes.
Automotive Seating and Interior Molding Cells: Meters precise chemical shot volumes into automated robot-dispensed foaming molds for automotive seat cushions, headrests, armrests, sound-deadening dash mats, and steering wheels.
Refrigeration and Appliance Thermal Insulation: Pumps polyurethane foaming formulations into domestic and commercial refrigerator cabinet walls, freezer lids, and commercial refrigerated display cases.
Polyurethane Elastomers and Cast Polyurethane: Provides continuous stepless flow adjustment for pouring high-grade polyurethane elastomers, mining hydrocyclones, heavy-duty conveyor scraper blades, and forklift wheels.
Shoe Sole and Footwear Production Machinery: Delivers reliable, pulsation-free metering into multi-station rotary casting machines for single-, dual-, and triple-density polyurethane footwear soles.
| Key Specifications Overview
| Parameter | Engineering Specification (Polyurethane Metering Standard) |
|---|---|
| Series Architecture | Variable Bent-Axis Axial Piston Rotary Group with Tapered Piston Dosing Technology (HYH2VK Series) |
| Standard Displacement Frame Sizes | 4 Standard Frame Sizes: HYH2VK 012 (Series 4), HYH2VK 028 (Series 1), HYH2VK 055 (Series 1), HYH2VK 107 (Series 1) |
| Circuit Configurations | Open Circuit Design (HYH2VKO, internal case drain) / Closed Circuit Design (HYH2VKG, external case drain lines) |
| Nominal Continuous Pressure (p_N) | 250 bar (3,625 psi / 25 MPa) continuous working pressure at service line ports A or B (to DIN 24312) |
| Maximum Peak Operating Pressure (p_max) | 315 bar (4,568 psi / 31.5 MPa) peak operating pressure |
| Open Circuit Suction Port Limits (Port S) | Minimum filling pressure: p_min = 1.0 bar absolute; Maximum filling pressure: p_max = 10.0 bar (145 psi) absolute |
| Closed Circuit Port Limits (Ports A/B & T) | Maximum leakage fluid pressure: p_L max = 10.0 bar absolute; Max intermittent cumulative pressure A + B: 250 bar |
| Maximum Case Leakage Pressure (p_L max) | 10.0 bar (145 psi) absolute at ports T1 / T2 (pump housing must remain completely filled with fluid at all times) |
| Geometric Displacement Range (Vg) | Stepless variation from Vg_min = 0 cm³/rev up to Vg_max: 11.6 cm³ (012), 28.1 cm³ (028), 54.8 cm³ (055), 107.0 cm³ (107) |
| Delivery Flow Range @ 1450 rpm (qv max) | 16.3 L/min (HYH2VK 012), 39.5 L/min (HYH2VK 028), 77.1 L/min (HYH2VK 055), 150.5 L/min (HYH2VK 107) |
| Delivery Flow Range @ 1800 rpm (qv max) | 20.3 L/min (HYH2VK 012), 49.1 L/min (HYH2VK 028), 95.7 L/min (HYH2VK 055), 186.8 L/min (HYH2VK 107) |
| Drive Power Consumption @ 250 bar (1450 rpm) | 6.8 kW (HYH2VK 012), 16.5 kW (HYH2VK 028), 32.1 kW (HYH2VK 055), 62.7 kW (HYH2VK 107) |
| Drive Power Consumption @ 250 bar (1800 rpm) | 8.4 kW (HYH2VK 012), 20.4 kW (HYH2VK 028), 39.9 kW (HYH2VK 055), 77.8 kW (HYH2VK 107) |
| Manual Control Unit (MA Control) | Self-locking threaded spindle handwheel with integral mechanical precision measuring scale |
| Handwheel Turns (Vg_0 to Vg_max) | 10.6 turns (012), 12.7 turns (028), 16.0 turns (055), 13.4 turns (107); Max adjusting force F_max: 70 ~ 120 N |
| Shaft Sealing & Buffer Fluid System | Double shaft seal arrangement with 4 buffer fluid ports (U1~U4 M10 × 1; 8 mm deep, 30 Nm max) |
| Mounting Flange Standard | ISO 3019-2 4-bolt metric: 80-4 (012, Ø80h9), 100-4 (028, Ø100h9), 125-4 (055, Ø125h9), 160-4 (107, Ø160h9) |
| Drive Shaft Configuration | Cylindrical shaft with parallel key to DIN 6885: P (Ø20 mm for 012; Ø25 mm for 028; Ø30 mm for 055; Ø40 mm for 107) |
| Corrosion Protection Option (SO2) | Specialized anti-corrosion surface treatment (SO2) for operating in humid chemical plant environments |
| Compatible Chemical Fluids | Polyurethane manufacturing components (polyol and isocyanate); mineral hydraulic oils HLP DIN 51524 |
| Operating Viscosity Range | Kinematic viscosity: ν_min = 1 mm²/s to ν_max = 2000 mm²/s |
| Operating Temperature Range | Optimum operating temperature range: +10°C to +50°C; Maximum fluid temperature: t_max = +80°C |
| Recommended Filtration Grade | Absolute filtration rating: η_abs ≤ 125 µm arranged in pump suction line before chemical fluid entry |
| Technical Performance Matrix Across Available Sizes
| Model Code | Displacement (cm³/rev) | Operating Pressure (bar / psi) | Max Delivery Flow qv max (L/min) | Max Drive Power @ 250 bar (kW) | Handwheel Turns (Vg_0 to Vg_max) | Pump Mass (kg, approx) | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Vg_max | Vg_min | Nominal (p_N) | Peak (p_max) | @ 735 rpm | @ 970 rpm | @ 1450 rpm | @ 1800 rpm | @ 735 rpm | @ 970 rpm | @ 1450 rpm | @ 1800 rpm | |||
| HYH2VK 012 | 11.6 | 0 | 250 / 3,625 | 315 / 4,568 | 8.3 | 10.9 | 16.3 | 20.3 | 3.4 | 4.5 | 6.8 | 8.4 | 10.6 | 19.0 |
| HYH2VK 028 | 28.1 | 0 | 250 / 3,625 | 315 / 4,568 | 20.0 | 26.4 | 39.5 | 49.1 | 8.3 | 11.0 | 16.5 | 20.4 | 12.7 | 36.0 |
| HYH2VK 055 | 54.8 | 0 | 250 / 3,625 | 315 / 4,568 | 39.1 | 51.6 | 77.1 | 95.7 | 16.3 | 21.5 | 32.1 | 39.9 | 16.0 | 64.0 |
| HYH2VK 107 | 107.0 | 0 | 250 / 3,625 | 315 / 4,568 | 76.3 | 100.7 | 150.5 | 186.8 | 31.8 | 41.9 | 62.7 | 77.8 | 13.4 | 117.0 |
| Structural Variations: Open Circuit (HYH2VKO) vs. Closed Circuit (HYH2VKG)
| Structural Configuration | Hydraulic Routing & Case Drain Design | Permissible Pressure Envelope | Field Operational Benefit |
|---|---|---|---|
| Open Circuit Design (HYH2VKO) | Suction port S is connected internally to the pump housing cavity. No external leakage line is required; case leakage ports T1 and T2 are sealed with factory screw plugs. | Suction port S filling pressure: 1.0 bar min to 10.0 bar max absolute; Nominal pressure: 250 bar; Peak: 315 bar. | Standard metering applications with day-tank or transfer pump feeding. Eliminates external drain hosing and simplifies machine frame layout. |
| Closed Circuit Design (HYH2VKG) | Service ports A and B are completely isolated from the pump housing cavity. Internal leakage fluid must be removed via port T1 or T2 using a dedicated return line to the reservoir. | Housing leakage fluid pressure: max 10.0 bar absolute; Maximum intermittent cumulative pressure A + B: 250 bar. | High-viscosity polyols and pressurized circulation systems. Prevents high chemical feed pressure from loading the rotating shaft seal. |
| High-Precision Manual Adjustment Mechanism (MA Control) & Integrated Double Shaft Seal System
| System Module | Technical Design & Components | Operating Mechanics | Process Protection & Operational Advantage |
|---|---|---|---|
| MA Manual Adjustment Unit | Self-locking threaded spindle handwheel with integrated mechanical precision measuring scale. | Stepless displacement adjustment from Vg_0 to Vg_max across 10.6 to 16.0 spindle revolutions; handwheel force: 70 ~ 120 N. | Can be mounted on the left side (Version 1) or right side (Version 2) looking onto the drive shaft. Guarantees precise, reproducible chemical ratio settings. |
| Double Shaft Seal & Buffer Fluid Chamber | Dual chemical-grade radial shaft sealing rings forming an intermediate buffer/barrier fluid chamber. | 4 radial buffer fluid connection ports (U1, U2, U3, U4; M10 × 1; 8 mm deep, tightening torque max 30 Nm). | Allows constant circulation of plasticizer/barrier liquid (e.g. Mesamoll) to prevent air moisture ingress, eliminate isocyanate crystallization, and protect the plant environment. |
| Housing Air Bleed Port (Port R) | Dedicated air bleed port R (M12 × 1.5, DIN 3852; tightening torque max 50 Nm) located on top of the pump housing. | Enables complete deaeration and air bleeding of the housing during initial fluid pre-filling and commissioning. | Prevents air entrapment in the bearing and rotary group area, eliminating cavitation and ensuring optimal lubricating film formation. |
| Optional Flanged Pressure Limiting Valve | Direct-acting pressure limiting valve flanged directly to pump service port B1 with separate tank return connection port T3. | Directly limits maximum service line pressure at the pump head (Option 1 in type code). | Protects high-pressure mixing heads, injection nozzles, and distribution hoses against overpressure spikes during rapid shut-off cycles. |
| Mounting Flange, Shaft and Port Specifications
| Model Size | Mounting Flange (ISO 3019-2 4-Bolt) | Drive Shaft (DIN 6885 Cylindrical Keyed) | Service & Auxiliary Ports (DIN 3852 / DIN ISO 228) |
|---|---|---|---|
| HYH2VK 012 | ISO 3019-2 80-4; Centering pilot Ø80h9 mm; 4 × Ø9 mm through holes; bolt circle Ø100 mm | Shaft Code P: Cylindrical keyed DIN 6885 – A6 × 6 × 25.5 (Ø20 mm fit k6); center bore M6 × 1 (10 mm deep) | Service A, B: M22 × 1.5 (210 Nm); Suction S: G 1 1/4 (720 Nm); Leakage T1, T2: M12 × 1.5 (50 Nm); Air bleed R: M12 × 1.5 (50 Nm); Buffer U1~U4: M10 × 1 (30 Nm) |
| HYH2VK 028 | ISO 3019-2 100-4; Centering pilot Ø100h9 mm; 4 × Ø9 mm through holes; bolt circle Ø125 mm | Shaft Code P: Cylindrical keyed DIN 6885 – AS8 × 7 × 40 (Ø25 mm fit k6); center bore M8 × 1.25 (11 mm deep) | Service A, B: M27 × 2 (330 Nm); Suction S: G 1 1/2 (960 Nm); Leakage T1, T2: M16 × 1.5 (100 Nm); Air bleed R: M12 × 1.5 (50 Nm); Buffer U1~U4: M10 × 1 (30 Nm) |
| HYH2VK 055 | ISO 3019-2 125-4; Centering pilot Ø125h9 mm; 4 × Ø11 mm through holes; bolt circle Ø160 mm | Shaft Code P: Cylindrical keyed DIN 6885 – AS8 × 7 × 43 (Ø30 mm fit k6); center bore M10 × 1.5 (12.5 mm deep) | Service A, B: M33 × 2 (540 Nm); Suction S: G 2 (1200 Nm); Leakage T1, T2: M18 × 1.5 (140 Nm); Air bleed R: M12 × 1.5 (50 Nm); Buffer U1~U4: M10 × 1 (30 Nm) |
| HYH2VK 107 | ISO 3019-2 160-4; Centering pilot Ø160h9 mm; 4 × Ø14 mm through holes; bolt circle Ø200 mm | Shaft Code P: Cylindrical keyed DIN 6885 – AS12 × 8 × 63 (Ø40 mm fit k6); center bore M12 × 1.75 (15 mm deep) | Service A, B: M42 × 2 (720 Nm); Suction S: G 2 1/2 (2000 Nm); Leakage T1, T2: M18 × 1.5 (140 Nm); Air bleed R: M12 × 1.5 (50 Nm); Buffer U1~U4: M10 × 1 (30 Nm) |
| Direct Interchangeability and OEM Replacement Matrix (Rexroth A2VK Series 1 & 4)
| Hengyuhang Series | OEM Target Model | OEM Part Reference Code | Interchangeability and Drop-In Compliance |
|---|---|---|---|
| HYH2VK 012 | Bosch Rexroth A2VK 12 Series 4 | A2VK 12 MA O R 4 G 0 P E 1 - SO2 | 100% direct dimensional and hydraulic drop-in replacement; identical ISO 80-4 flange, Ø20 mm cylindrical keyed shaft P, M22 × 1.5 ports, G 1 1/4 suction, and 10.6-turn MA handwheel. |
| HYH2VK 028 | Bosch Rexroth A2VK 28 Series 1 | A2VK 28 MA O R 1 G 0 P E 1 - SO2 | Direct replacement for polyurethane metering units; identical ISO 100-4 flange, Ø25 mm keyed shaft, G 1 1/2 suction port, M27 × 2 service ports, and 39.5 L/min flow rating @ 1450 rpm. |
| HYH2VK 055 | Bosch Rexroth A2VK 55 Series 1 | A2VK 55 MA O R 1 G 0 P E 1 - SO2 | Direct drop-in replacement for medium-high flow continuous polyurethane foaming lines; features ISO 125-4 flange, Ø30 mm keyed shaft, G 2 suction port, and 77.1 L/min delivery @ 1450 rpm. |
| HYH2VK 107 | Bosch Rexroth A2VK 107 Series 1 | A2VK 107 MA O R 1 G 0 P E 1 - SO2 | Maximum-displacement polyurethane metering pump replacement; identical ISO 160-4 flange, Ø40 mm keyed shaft, M42 × 2 service ports, G 2 1/2 suction, and 150.5 L/min flow @ 1450 rpm. |
| HYH2VK Closed Circuit | Rexroth A2VK...G Series | A2VK ... MA G R ... G 0 P E ... | Full closed-circuit replacement with isolated pump casing for high chemical feed pressures and dedicated T1/T2 case drain line return. |
| HYH2VK with Relief Valve | Rexroth A2VK with Attached Valve | A2VK ... MA ... 1 P E ... (Valve attached) | Direct interchangeable pump-mounted direct-acting pressure limiting valve with service port B1 and return line connection port T3. |
| Technical Performance Matrix Across Available Sizes
| Model Code | Displacement (cm³/rev) | Operating Pressure (bar / psi) | Max Delivery Flow qv max (L/min) | Max Drive Power @ 250 bar (kW) | Handwheel Turns (Vg_0 to Vg_max) | Pump Mass (kg, approx) | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Vg_max | Vg_min | Nominal (p_N) | Peak (p_max) | @ 735 rpm | @ 970 rpm | @ 1450 rpm | @ 1800 rpm | @ 735 rpm | @ 970 rpm | @ 1450 rpm | @ 1800 rpm | |||
| HYH2VK 012 | 11.6 | 0 | 250 / 3,625 | 315 / 4,568 | 8.3 | 10.9 | 16.3 | 20.3 | 3.4 | 4.5 | 6.8 | 8.4 | 10.6 | 19.0 |
| HYH2VK 028 | 28.1 | 0 | 250 / 3,625 | 315 / 4,568 | 20.0 | 26.4 | 39.5 | 49.1 | 8.3 | 11.0 | 16.5 | 20.4 | 12.7 | 36.0 |
| HYH2VK 055 | 54.8 | 0 | 250 / 3,625 | 315 / 4,568 | 39.1 | 51.6 | 77.1 | 95.7 | 16.3 | 21.5 | 32.1 | 39.9 | 16.0 | 64.0 |
| HYH2VK 107 | 107.0 | 0 | 250 / 3,625 | 315 / 4,568 | 76.3 | 100.7 | 150.5 | 186.8 | 31.8 | 41.9 | 62.7 | 77.8 | 13.4 | 117.0 |
| Hengyuhang Series | OEM Target Model | OEM Part Reference Code | Interchangeability and Drop-In Compliance |
|---|---|---|---|
| HYH2VK 012 | Bosch Rexroth A2VK 12 Series 4 | A2VK 12 MA O R 4 G 0 P E 1 - SO2 | 100% direct dimensional and hydraulic drop-in replacement; identical ISO 80-4 flange, Ø20 mm cylindrical keyed shaft P, M22 × 1.5 ports, G 1 1/4 suction, and 10.6-turn MA handwheel. |
| HYH2VK 028 | Bosch Rexroth A2VK 28 Series 1 | A2VK 28 MA O R 1 G 0 P E 1 - SO2 | Direct replacement for polyurethane metering units; identical ISO 100-4 flange, Ø25 mm keyed shaft, G 1 1/2 suction port, M27 × 2 service ports, and 39.5 L/min flow rating @ 1450 rpm. |
| HYH2VK 055 | Bosch Rexroth A2VK 55 Series 1 | A2VK 55 MA O R 1 G 0 P E 1 - SO2 | Direct drop-in replacement for medium-high flow continuous polyurethane foaming lines; features ISO 125-4 flange, Ø30 mm keyed shaft, G 2 suction port, and 77.1 L/min delivery @ 1450 rpm. |
| HYH2VK 107 | Bosch Rexroth A2VK 107 Series 1 | A2VK 107 MA O R 1 G 0 P E 1 - SO2 | Maximum-displacement polyurethane metering pump replacement; identical ISO 160-4 flange, Ø40 mm keyed shaft, M42 × 2 service ports, G 2 1/2 suction, and 150.5 L/min flow @ 1450 rpm. |
| HYH2VK Closed Circuit | Rexroth A2VK...G Series | A2VK ... MA G R ... G 0 P E ... | Full closed-circuit replacement with isolated pump casing for high chemical feed pressures and dedicated T1/T2 case drain line return. |
| HYH2VK with Relief Valve | Rexroth A2VK with Attached Valve | A2VK ... MA ... 1 P E ... (Valve attached) | Direct interchangeable pump-mounted direct-acting pressure limiting valve with service port B1 and return line connection port T3. |
WhatsApp
Email
+86 19918575358
