PRB-8A-2D-Y-Z Winner Hydraulics Direct-Acting Proportional Pilot Relief Valve
The Winner Hydraulics PRB-8A-2D-Y-Z is a standard direct-acting, poppet-type proportional relief valve with pilot capacity, for the 8A-2 cavity. It works on a “current up, pressure up” principle: with no command it sits at low pressure, and as coil current increases the relief setting rises proportionally. Rated to 350 bar with 1 L/min rated pilot flow (2 L/min maximum), it uses a 19 mm tube with a 22 W EC-19A coil. It is a common electro-proportional pilot for Winner relief main stages with an integral 8A control cavity.
How the PRB-8A-2D-Y-Z Operates
The analog input signal sets the solenoid force on the poppet. When pressure at port 1 overcomes that force, the poppet lifts and allows flow from port 1 to port 2, limiting pressure at the commanded value. With zero current the valve relieves at low pressure, and higher current raises the setting. Back pressure at port 2 (tank) adds to the setting at a 1:1 ratio.
PRB-8A-2D-Y-Z Technical Specifications
| Specification | Value |
|---|---|
| Valve type | Standard direct-acting, poppet-type, pilot capacity proportional relief valve |
| Function | Low pressure with no command |
| Cavity | 8A-2 |
| Thread | M16 x 1.5 |
| Rated flow | 1 L/min (0.26 gpm) |
| Maximum flow | 2 L/min (0.53 gpm) |
| Max. operating pressure | 350 bar (5000 psi) |
| Valve hex size | 22.22 mm (7/8 in) |
| Installation torque | 27–33 Nm (20–24 lbf-ft) |
| Max. leakage at reseat | Approx. 25 cc/min |
| Reseat | Exceeds 85% of cracking pressure |
| Hysteresis | < 8% with DC input; < 4% with dither |
| Linearity with dither | < 2% |
| Recommended dither | 100–250 Hz (best 140–200 Hz) |
| Coil | EC-19A, 22 W, 19 mm tube (ordered separately) |
| Weight | 0.207 kg (Z = N, without coil) |
Control Pressure Ranges (Y)
| Y code | Maximum pressure | Best proportional control range |
|---|---|---|
| W | Up to 350 bar | 35–350 bar |
| A | Up to 210 bar | 20–210 bar |
| B | Up to 105 bar | 10.5–105 bar |
| D | Up to 50 bar | 3.5–50 bar |
Control Options (Z)
| Z code | Option | Description |
|---|---|---|
| N | Non-adjustable | Standard version, with plastic tamper-resistant cover |
| P | Manual override, push style | For emergency or test use |
| M | Manual control adjustment screw | Allows manual pressure adjustment in case of electrical failure; supplied fully open from the factory |
Features
- Proportional pressure increase with rising current
- Low pressure at zero command
- Four control ranges, from 3.5 bar up to 350 bar
- Optional manual override (P) or manual adjustment screw (M)
- Continuous-duty rated coil with efficient wet-armature construction
- Low hysteresis (< 4%) and linearity (< 2%) with dither
- Heat-treated, 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
Winner recommends a current-sensing amplifier with dither for optimal control.
Main Stages Paired with the PRB-8A-2D-Y-Z
Winner lists the PRB-8A-2D-Y-Z as a direct-acting proportional pilot for its relief main stages with integral 8A control cavity, including:
- Balanced poppet: RP-10A-2G-Y-8, RP-3A-2G-Y-8, RP-16A-2G-Y-8, RP-18A-2G-Y-8
- Balanced piston: RP-10A-20-Y-8, RP-3A-20-Y-8, RP-16A-20-Y-8, RP-10W-2S-Y-8, RP-22MA-2S-Y-8, RP-18A-20-Y-Z
Need the Reverse Function?
| Model | At zero current | Pressure as current rises |
|---|---|---|
| PRB-8A-2D-Y-Z | Low pressure | Increases |
| PRA-8A-2D-Y-Z-74 | High pressure | Decreases |
| PRB-8A-2C-Y-Z | Low pressure | Increases (16 mm tube version) |
Winner’s datasheet directs buyers who need the inverse function to the PRA-8A-2D-Y-Z-74.
Buy the PRB-8A-2D-Y-Z Winner Hydraulics
Atlantech Drives supplies genuine Winner Hydraulics electro-proportional valves worldwide, with fast shipping. Tell us the control range (W, A, B or D), the option (N, P or M) and the coil voltage, and our commercial team will quote the PRB-8A-2D-Y-Z and its EC-19A coil with availability and lead time. Get your quote today.
