Normally closed, balanced poppet, logic element with integral T-8A control cavity - vent-to-open

Capacity: 30 gpm120 L/min. | Cavity: T-22A
DKFR8 : Normally closed, balanced poppet, logic element with integral T-8A control cavity - vent-to-open
Technical Features [ + ]

This is a normally closed, balanced poppet, switching element with an integral T-8A control cavity. With a 2-way valve in the closed position installed in the T-8A control cavity, the poppet remains closed. Opening the 2-way valve shifts the poppet to the open position, provided there is sufficient pressure at port 3.

  • Unique balanced construction provides predictable switching with 5000 psi (350 bar) at port 1 and port 2. Switching will only occur when both a minimum pilot pressure of 400 psi (30 bar) is present and pilot control valve is open.
  • These valves are hydraulically balanced between port 1 and port 2.
  • Port 1 and port 2 are fully sealed from port 3 and port 4. Ports 3 and 4 are positively sealed.
  • Any backpressure at the drain port is directly additive to the required pilot pressure for reliable operation.
  • Leakage rate between port 1 and port 2 is very low, typically less than 10 drops/min. at 5000 psi (0,7 cc/min at 350 bar).
  • Valve will reseat when the pilot pressure falls below 145 psi (10 bar).
  • NOTE: With the -8 control option, the main stage valve should first be installed to the correct torque value. The T-8A pilot control valve should then be installed into the main stage valve to its required torque value.
  • The -8 control option allows the pilot control valve to be incorporated directly into the end of the logic cartridge via the T-8A cavity. These pilot control cartridges are sold separately and include electro-proportional, solenoid, air pilot, and hydraulic pilot operation. See Pilot Control Cartridges.
  • All ports will accept 5000 psi (350 bar).
  • 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.
Back to Top
Technical Data [ + ]
Note: Data may vary by configuration. See CONFIGURATION section.
Cavity T-22A
Series 2
Capacity 30 gpm120 L/min.
Maximum Operating Pressure 5000 psi350 bar
Minimum Pilot Pressure Required to Shift Valve 300 psi20 bar
Control Pilot Flow See Performance DataSee Performance Data
Maximum Valve Leakage at 110 SUS (24 cSt) 10 drops/min.@5000 psi0,7 cc/min.@350 bar
Pilot Control Cavity T-8AT-8A
Pilot Control Valve Installation Torque 20 - 25 lbf ft27 - 33 Nm
Pilot Control Valve Hex Size 7/8 in.22,2 mm
Valve Hex Size 1 1/8 in.28,6 mm
Valve Installation Torque 45 - 50 lbf ft61 - 68 Nm
Model Weight .65 lb0,30 kg
Seal kit - Cartridge Buna: 990022007
Seal kit - Cartridge Polyurethane: 990022002
Seal kit - Cartridge Viton: 990022006
Back to Top
Performance Curves [ + ]
Performance Curve for DKFR8: Normally closed, balanced poppet, logic element with integral T-8A control cavity - vent-to-open
Back to Top
FAQs [ + ]
How big is a drop of hydraulic oil?  

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

Direct acting or pilot operated - what do I use?

Direct-acting valves are used to prevent over pressure, and pilot-operated valves are used to regulate pressure. If you are unsure, use a direct-acting valve. Sun's direct acting valves are very fast, dirt tolerant, stable, and robust. Sun's pilot-operated valves are moderately fast, they have a low pressure rise vs. flow curve, and they are easy to adjust.

I need to discharge a large accumulator. How can I increase the capacity of my discharge circuit?

Because of the very high ratio, the COFO has limited capacity. The discharge path is across a .050 inch (1,3 mm) diameter orifice. If you have large accumulators combined with low precharge pressures, this may not discharge the energy quickly enough. Using the COFO XDN cartridge in conjunction with an LODA XDN will provide capacity for larger applications.

What parts of the Sun cartridge valve are field serviceable?
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.
Back to Top
  • DKFRNormally closed, balanced poppet, logic element - vent-to-open
Back to Top
Notes [ + ]
  • Compound cartridge (pilot and main stage) assembly information is provided for reference only. Cartridges must be ordered separately and assembled at point of use.
Back to Top
Additional Resources [ + ]
Highlights
Technical Tips
Technical Information
Back to Top