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The accumulator sense, pump unload pilot valve is used to sense pressure in an accumulator at port 2 of the valve and when the pressure at port 2 reaches the valve setting, port 3 connects to port 4 to vent a relief valve and unload the pump. This valve has a 20% ratio between unload setting and reset; when pressure at port 2 falls below 80% of the valve setting, port 3 is blocked from port 4 and the pump will come back online to recharge the accumulator.
The integral free-flow check valve is suitable for pump flows up to 15 gpm (60 L/min). For higher capacity pumps, another version of accumulator sense, pump unload cartridge, QPAB, which requires a separate check cartridge is available.
Note: Data may vary by configuration. See CONFIGURATION section.
| Cavity | T-21A |
| Series | 1 |
| Capacity | 15 gpm |
| Capacity (metric) | 60 L/min. |
| Maximum Operating Pressure | 5000 psi |
| Maximum Operating Pressure (metric) | 350 bar |
| Check Cracking Pressure | 4 psi |
| Check Cracking Pressure (metric) | 0,3 bar |
| Pressure Drop, Port 1 to Port 2 | 100 psi@15 gpm |
| Pressure Drop, Port 1 to Port 2 (metric) | 7 bar@60 L/min. |
| Pilot Flow Capacity | 46 in³/min. |
| Pilot Flow Capacity (metric) | 0,75 L/min. |
| Adjustment – No. of CW Turns from Min. to Max. setting | 5 |
| Valve Hex Size | 7/8 in. |
| Valve Hex Size (metric) | 22,2 mm |
| Valve Installation Torque | 30 – 35 lbf ft |
| Valve Installation Torque (metric) | 41 – 47 Nm |
| Adjustment Screw Internal Hex Size | 5/32 in. |
| Adjustment Screw Internal Hex Size (metric) | 4 mm |
| Locknut Hex Size | 9/16 in. |
| Locknut Hex Size (metric) | 15 mm |
| Locknut Torque | 80 – 90 lbf in. |
| Locknut Torque (metric) | 9 – 10 Nm |
| Model Weight | 0.42 lb. |
| Model Weight (metric) | 0.19 kg. |
| Seal kit – Cartridge | Viton: 990021006 |
Control
| C | Tamper Resistant – Factory Set |
| L | Standard Screw Adjustment |
| K | Handknob |
Adjustment Range
| A | 1000 – 3000 psi (70 – 210 bar), 1000 psi (70 bar) Standard Setting |
| B | 500 – 1500 psi (35 – 105 bar), 500 psi (35 bar) Standard Setting |
| C | 2000 – 5000 psi (140 – 350 bar), 2000 psi (140 bar) Standard Setting |
| D | 250 – 800 psi (18 – 55 bar), 250 psi (18 bar) Standard Setting |
Seal Material
| N | Buna-N |
| V | Viton |
Material/Coating
| /AP | Stainless Steel, Passivated |
| /LH | Mild Steel, Zinc-Nickel |
