Hydraulic Relief Valve MRV Series
Yuken MRV / MBRV Compatible
A relief valve is the pressure ceiling of a hydraulic system — it decides the maximum load your pump, hoses and actuators will ever see. YXCHK manufactures the MRV direct-acting and MBRV two-stage relief valve families in 02 (NG6) and 03 (NG10) sizes, rated at 25 MPa, as drop-in equivalents for the Yuken MRV and MBRV series. Every unit is 100% factory tested and Intertek certified.
25 MPa · NG6 / NG10
What a Relief Valve Actually Does
A hydraulic relief valve is a normally-closed pressure control device. It stays shut while system pressure is below its setting; once pressure reaches the setting, the valve opens and diverts flow to tank, capping the pressure the rest of the circuit can experience. Without it, a blocked actuator or closed directional valve would drive pump pressure until something fails — a hose, a seal, or the pump itself.
Three duties are common in industrial circuits. Main system relief sits on the pump line and sets the machine's maximum pressure — this is the P-port configuration. Port relief protects an individual actuator line against shock or thermal expansion — the A and B port configurations. Vent / unloading duty uses a pilot-operated valve whose remote vent port can dump pump flow to tank on command, which is how many machines unload during idle.
The YXCHK pressure control line covers all three: MRV in P, A and B configurations, MBRV as a two-stage balanced type, and the MPCV pilot-operated check valve for load holding. All are dimensionally matched to the Yuken pattern in 02 (NG6) and 03 (NG10) sizes.
MRV Direct-Acting vs MBRV Two-Stage
The choice between the two families is about pressure stability across the flow range, not about pressure rating — both are 25 MPa.
| Attribute | MRV — Direct-Acting | MBRV — Two-Stage (Balanced Pilot) |
|---|---|---|
| Operating principle | Pressure acts directly on spring-loaded poppet | Small pilot stage controls larger main stage |
| Max working pressure | 25 MPa | 25 MPa |
| Max T-port pressure | 25 MPa | 25 MPa |
| Flow — 02 / NG6 size | 100 L/min | 100 L/min |
| Flow — 03 / NG10 size | 200 L/min | 200 L/min |
| Pressure-flow curve | Steeper — pressure rises with flow | Flatter — more stable across range |
| Response speed | Faster (fewer moving stages) | Slightly slower, smoother |
| Port configurations | P / A / B | P port, 2-stage (-1 / -2 variants) |
| Best suited to | Simple circuits, port relief, shock protection | Main relief at high flow, stable pressure duty |
| Hydraulic fluid | Mineral oil per ISO 6743/4 | Mineral oil per ISO 6743/4 |
Complete MRV / MBRV Model Table
All 10 relief valve models currently in YXCHK production. Click any model for its full datasheet.
| YXCHK Model | Type | Size | Max Pressure | Max Flow | Port / Function | Replaces |
|---|---|---|---|---|---|---|
| MRV-02-P | Direct-acting | 02 (NG6) | 25 MPa | 100 L/min | P port — main relief | Yuken MRV-02 |
| MRV-02-A | Direct-acting | 02 (NG6) | 25 MPa | 100 L/min | A port — port relief | Yuken MRV-02 |
| MRV-02-B | Direct-acting | 02 (NG6) | 25 MPa | 100 L/min | B port — port relief | Yuken MRV-02 |
| MRV-03-P | Direct-acting | 03 (NG10) | 25 MPa | 200 L/min | P port — main relief | Yuken MRV-03 |
| MRV-03-A | Direct-acting | 03 (NG10) | 25 MPa | 200 L/min | A port — port relief | Yuken MRV-03 |
| MRV-03-B | Direct-acting | 03 (NG10) | 25 MPa | 200 L/min | B port — port relief | Yuken MRV-03 |
| MBRV-02-P-1 | 2-stage pilot | 02 (NG6) | 25 MPa | 100 L/min | P port, 2-stage | Yuken MBRV-02 |
| MBRV-02-P-2 | 2-stage pilot | 02 (NG6) | 25 MPa | 100 L/min | P port, 2-stage | Yuken MBRV-02 |
| MBRV-03-P-1 | 2-stage pilot | 03 (NG10) | 25 MPa | 200 L/min | P port, 2-stage | Yuken MBRV-03 |
| MBRV-03-P-2 | 2-stage pilot | 03 (NG10) | 25 MPa | 200 L/min | P port, 2-stage | Yuken MBRV-03 |
Related pressure control: MPCV-02-W and MPCV-03-W pilot-operated check valves (21 MPa, 100 L/min) for load-holding duty — see catalog.
Reading the Model Code
Using MBRV-03-P-2 as the worked example:
| Segment | Meaning | Options |
|---|---|---|
| MBRV | Valve family | MRV = direct-acting relief · MBRV = 2-stage balanced relief · MPCV = pilot-operated check |
| 03 | Body size | 02 = NG6 (100 L/min) · 03 = NG10 (200 L/min) |
| P | Port configuration | P = pump line · A = A port · B = B port · W = pilot-operated (MPCV) |
| 2 | Pressure range variant | -1 / -2 on MBRV models — confirm required adjustment range at inquiry |
If you are replacing an existing valve, copy the code from the nameplate exactly, including any suffix. The -1 and -2 variants on the MBRV series differ in pressure adjustment range, and fitting the wrong variant means the valve cannot be set to your required cracking pressure even though it bolts on correctly.
Four-Step Selection
Confirm size from flow — 02 or 03
The 02 (NG6) body handles up to 100 L/min; the 03 (NG10) body up to 200 L/min. Size from the flow that will actually pass through the valve when it is relieving — for a main relief, that is full pump delivery.
Choose direct-acting or two-stage
MRV for fast response and simple circuits, or where the valve only relieves occasionally against shock. MBRV where the valve relieves continuously at high flow and system pressure must stay flat — for example a fixed-displacement pump circuit that spends much of its cycle over relief.
Pick the port configuration
P for main system pressure limiting. A or B for protecting an individual actuator line against shock loads or thermal expansion when the directional valve is closed-centre — a common requirement on clamping circuits using an E-spool directional valve.
Verify setting range and fluid
Confirm the required cracking pressure sits inside the valve's adjustment range — state it at inquiry so the correct MBRV variant (-1 or -2) is supplied. Standard fluid compatibility is mineral oil per ISO 6743/4; specify other fluids explicitly.
Rexroth DB / DBW Cross-Reference Notes
Engineers replacing a Rexroth pressure valve often ask whether an MRV or MBRV will fit. The honest answer requires separating two questions: functional equivalence and mounting equivalence.
| Rexroth family | Function | Nearest YXCHK family | Mounting note |
|---|---|---|---|
| DB (direct-acting) | Pressure relief, direct type | MRV series | Different pattern — confirm sub-plate |
| DB (pilot-operated) | Pressure relief, pilot type | MBRV series | Different pattern — confirm sub-plate |
| DBW | Pilot relief with solenoid unloading | MBRV + directional valve | Circuit-level equivalent, not 1:1 part |
The practical rule: the MRV and MBRV families follow the Yuken mounting pattern, not the Rexroth DB/DBW pattern. Functionally they do the same job at comparable ratings, but you cannot assume the bolt pattern matches. Send the existing model code together with a photograph of the manifold face or the sub-plate drawing — YXCHK engineering confirms within 24 hours whether a direct fit is possible or an adapter plate is needed.
This differs from our directional valve line, where the ISO 4401 standard guarantees interchangeability across brands. For directional valves, see the 4WE6 cross reference table.
Frequently Asked Questions
What is the difference between MRV and MBRV relief valves?
MRV is direct-acting: pressure acts directly on a spring-loaded poppet, giving fast response but a steeper pressure-flow curve. MBRV is two-stage (pilot-operated): a small pilot controls a larger main stage, giving a flatter pressure characteristic and better stability at high flow. Both are rated 25 MPa. Choose MRV for simple circuits and fast response; MBRV where pressure must stay consistent as flow varies.
What do the -P, -A and -B suffixes mean on MRV valves?
The suffix identifies the port being controlled. MRV-02-P is the pump-line configuration for main system relief; MRV-02-A and MRV-02-B sense the A and B actuator ports for port-relief duty. All three share the same 02 (NG6) body, 25 MPa rating and 100 L/min capacity — selection depends only on which line needs protection.
Can a YXCHK MRV relief valve replace a Rexroth DB or DBW valve?
Functionally the families are equivalent, but mounting interfaces differ — MRV/MBRV follow the Yuken pattern, not Rexroth DB/DBW. Do not assume bolt-pattern interchangeability. Send your model code and manifold drawing; YXCHK engineering confirms within 24 hours whether a direct fit works or an adapter sub-plate is required.
Related Products & Guides
4WEH16 Electro-Hydraulic Series
NG16 pilot-operated, 31.5 MPa, 300 L/min.
DSG-02 Directional Valve
Yuken-compatible NG6, 21 MPa, 60 L/min.
Yuken Equivalent Guide
DSG-01 / 02 / 03 cross reference and model decoding.
Directional Valve Selection Guide
Size, spool, voltage and flow — five-step method.
Full Catalog (205 SKUs)
Directional, pressure control and check valve families.
Pressure Setting Consultation
Send circuit data — model and range confirmed in 24 h.