Normally open, balanced poppet, logic element - vent-to-close

Capacity: 15 gpm60 L/min. | Cavity: T-21A
DODR : Normally open, balanced poppet, logic element - vent-to-close
Technical Features [ + ]

This is a normally open, balanced poppet, switching element. When the vent port (port 4) is blocked, the poppet remains in the open position. Venting port 4 shifts it to the closed position, provided there is sufficient pressure at port 3.

  • Unique balanced construction provides predictable switching with 5000 psi (350 bar) at both ports 1 and 2, with the vent (port 4) open and a minimum pilot pressure of 400 psi (30 bar) at port 3.
  • Valve will open when the pilot pressure falls below 145 psi (10 bar).
  • 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.
  • 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).
  • Port 4 may be externally connected to a pilot switching valve. The pilot valve should have a leakage rate of less than 10 drops/min. and be able to satisfy the pilot flow requirements. Sun model DAA*-*** solenoid pilot valve is ideal for this application.
  • 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.
Technical Data [ + ]
Note: Data may vary by configuration. See CONFIGURATION section.
Cavity T-21A
Series 1
Capacity 15 gpm60 L/min.
Maximum Operating Pressure 5000 psi350 bar
Minimum Pilot Pressure Required to Shift Valve 400 psi28 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
Valve Hex Size 7/8 in.22,2 mm
Valve Installation Torque 30 - 35 lbf ft41 - 47 Nm
Model Weight .35 lb0,15 kg
Seal kit - Cartridge Buna: 990021007
Seal kit - Cartridge Polyurethane: 990021002
Seal kit - Cartridge Viton: 990021006
Performance Curves [ + ]
FAQs [ + ]

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.

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

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.

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 [ + ]