2-way, pilot-shifted, proportional throttle

Capacity: 5 gpm20 L/min. | Cavity: T-21A
FKBA : 2-way, pilot-shifted, proportional throttle
Technical Features [ + ]

This valve is a 2-way, 2-position proportional throttle. Ports 2 and 3 are normally closed. Pilot pressure at port 1 creates a metering orifice between port 2 and 3 that is proportional to the pressure at 1. The force balance of the flow forces, spring and pilot pressure results in a degree of partial self-compensation as the load pressure changes.

Pressure at port 4 directly opposes pressure at port 1.

  • An optional tuning adjustment (L control) is offered to vary the pilot pressure required to control flow. The tuning adjustment provides a means to manually increase or decrease flow at a given pilot pressure. The adjustment range is 50 - 450 psi (3,5 - 30 bar), 100 psi (7 bar) Standard Setting.
  • These valves may be pressure compensated by an external, modulating, logic element. Use LR_C-XHN for a bypass circuit or LP_C-XHN for a restrictive circuit.
  • The valve provides a degree of self-compensation and may be used as a flow control. To increase the accuracy of flow control, an external, modulating, logic element can be used to maintain a constant flow over a wider range of flows and pressures. See performance curves for additional information.
  • Ports 1 and 4 should be limited to 500 psi (35 bar).
  • Pressure at port 4 directly opposes pressure at port 1.
  • Accurate pressure compensated control requires that a constant pressure differential be maintained across the valve.
  • Cartridges configured with EPDM seals are for use in systems with phosphate ester fluids. Exposure to petroleum based fluids, greases and lubricants will damage the seals.
  • Incorporates the Sun floating style construction to minimize the possibility of internal parts binding due to excessive installation torque and/or cavity/cartridge machining variations.
Technical Data [ + ]
Note: Data may vary by configuration. See CONFIGURATION section.
Cavity T-21A
Series 1
Capacity 5 gpm20 L/min.
Maximum Operating Pressure 5000 psi350 bar
Maximum Valve Leakage at 110 SUS (24 cSt) 2 in³/min.@1000 psi30 cc/min.@70 bar
Pilot Volume Displacement .02 in³0,33 cc
Minimum Pilot Pressure to Operate 100 psi7 bar
Hysteresis ± 2 %± 2 %
Adjustment - No. of CW Turns from Min. to Max. setting 55
Valve Hex Size 7/8 in.22,2 mm
Valve Installation Torque 30 - 35 lbf ft41 - 47 Nm
Adjustment Screw Internal Hex Size 5/32 in.4 mm
Locknut Hex Size 9/16 in.15 mm
Locknut Torque 80 - 90 lbf in.9 - 10 Nm
Model Weight .30 lb0,15 kg
Seal kit - Cartridge Buna: 990021007
Seal kit - Cartridge EPDM: 990021014
Seal kit - Cartridge Polyurethane: 990021002
Seal kit - Cartridge Viton: 990021006
Performance Curves [ + ]
FAQs [ + ]

There are exactly 250 Sun drops in a cubic inch or 15 in a cc.

Only external seals are serviceable.  Sun offers replacement seal kits for all cartridge models. The applicable kit part number can be found in the product page's Technical Data table or by using our Cartridge Seal Kit search function located under Accessories. Please note: Converting the external seals from one material to another does not ensure fluid compatibility with that material due to the existence of internal seals within the cartridge.
Additional Resources [ + ]