RP-18A-20-Y-Z Winner Hydraulics: 760 L/min Balanced Piston Relief Valve with Selectable Pilot Cavity
The Winner Hydraulics RP-18A-20-Y-Z is the highest-flow model in Winner’s balanced piston relief range with an integral pilot control cavity. It is rated for 760 L/min at 350 bar and installs in the 18A-2 (18AB-2) cavity with an M48 x 2.0 thread. Unlike the other models in the series, the RP-18A-20 lets you choose the pilot cavity: either a standard 8A-2 cavity or an 08W-2 cavity. That means one large-capacity main stage can match the pilot cartridge platform already used on your machine.
Understanding the RP-18A-20-Y-Z Part Number
| Code | Meaning | Options |
|---|---|---|
| RP | Pilot-operated relief | – |
| 18A | Main cavity | 18A-2 (18AB-2) |
| 20 | Main stage design | Balanced piston |
| Y | Spring | D: 1.7 bar (25 psi) min. control pressure; W: 7 bar (100 psi) min. control pressure |
| Z | Integral pilot cavity | 8: 8A-2 cavity; 8W: 08W-2 cavity |
Example configurations: RP-18A-20-D-8, RP-18A-20-W-8, RP-18A-20-D-8W, RP-18A-20-W-8W.
How the Valve Operates
The pilot cartridge installed in the integral cavity sets the relief pressure. When pressure at port 1 exceeds this setting, the balanced piston pilot-opens port 2 and meters flow from port 1 to port 2 (P to T) to regulate system pressure. The pilot setting defines the pressure differential between the ports. Back pressure at port 2 adds directly to the setting at a 1:1 ratio. Port 2 is rated for full pressure.
RP-18A-20-Y-Z Technical Data
| Specification | Value |
|---|---|
| Valve type | Pilot-operated, balanced piston relief, main stage with integral control cavity |
| Main cavity | 18A-2 (18AB-2) |
| Thread | M48 x 2.0 |
| Pilot cavity (Z) | 8A-2 (Z = 8) or 08W-2 (Z = 8W) |
| Rated flow | 760 L/min (200.77 gpm) |
| Max. operating pressure | 350 bar (5000 psi) |
| Hex size | 41.2 mm (1-5/8 in) |
| Installation torque | 465–500 Nm (343–369 lbf-ft) |
| Typical response time | 10 ms |
| Max. leakage | Approx. 82 cc/min at 70 bar (1000 psi) |
| Weight | 0.94 kg (2.07 lb) |
Highlights
- 760 L/min relief capacity in one screw-in cartridge
- Choice of 8A-2 or 08W-2 integral pilot cavity
- D or W spring to suit the required minimum control pressure and pressure drop
- Port 2 rated for full system pressure
- Stainless-steel filter screen on the pilot port for contamination resistance
- Heat-treated, high-precision ground working parts
- WINNERcoat® zinc-nickel plating, salt-spray tested to DIN EN ISO 9227 for up to 1000 hours
- Pressure rating tested to NFPA T2.6.1, with 90/90 fatigue rating assurance
- 100% functional test before shipment
- Multiple seal kit materials available
Selection Guidance from Winner
- Not suitable for load-holding applications, due to spool leakage.
- If high pressure drop could cause cavitation, noise or manifold erosion, Winner recommends the balanced poppet RP-18A-2G-Y-8.
- For rapid response and ultra-low leakage requirements, Winner offers its RD series.
Proportional Pilot Options
With the 8A-2 pilot cavity (Z = 8), Winner Hydraulics commonly pairs the RP-18A-20 with:
- PRB-8A-2D-Y-Z, PRB-8A-2C-Y-Z: direct-acting proportional pilot relief
- PRA-8A-2C-Y-Z, PRA-8A-2D-Y-Z-74: inverse direct-acting proportional pilot relief
RP-18A-20-Y-Z vs. RP-18A-2G-Y-8
| Feature | RP-18A-20-Y-Z | RP-18A-2G-Y-8 |
|---|---|---|
| Main stage | Balanced piston | Balanced poppet |
| Pilot cavity | 8A-2 or 08W-2 | 8A-2 |
| Rated flow | 760 L/min | 760 L/min |
| Typical response time | 10 ms | 7 ms |
| Max. leakage | Approx. 82 cc/min at 70 bar | Approx. 0.7 cc/min at reseat |
Balanced Piston Relief Range by Size
- RP-10A-20-Y-8 / RP-10W-2S-Y-8 / RP-22MA-2S-Y-8: 95 L/min
- RP-3A-20-Y-8: 200 L/min
- RP-16A-20-Y-8: 380 L/min
- RP-18A-20-Y-Z: 760 L/min
Get a Quote for the RP-18A-20-Y-Z Winner Hydraulics
Atlantech Drives supplies original Winner Hydraulics cartridge valves to industrial customers worldwide, with fast shipping. Tell us the spring code (D or W) and pilot cavity (8 or 8W) you need, and our commercial team will confirm availability, seal material, pricing and lead time for your RP-18A-20 order. Request your quote today.
