Normally open, balanced poppet, logic element - pressure adjustable

Capacity: 15 gpm60 L/min. | Cavity: T-21A
DODP : Normally open, balanced poppet, logic element - pressure adjustable
Technical Features [ + ]

This is a normally open, balanced poppet, switching element. When pilot pressure is applied to port 3, the poppet remains open until the pilot pressure reaches the setting established by the integral pilot relief stage, at which point the poppet shifts to the closed position.

  • Unique balanced construction provides predictable switching with 5000 psi (350 bar) at both port 1 and port 2. When the remote pressure signal at port 3 exceeds the internal valve setting, the valve shifts to the closed position.
  • Any backpressure at the drain port is directly additive to the valve setting.
  • 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).
  • Valve will return to the spring-biased open position when pilot pressure reaches approx. 85% of cracking value.
  • 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
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
Seal kit - Cartridge Buna: 990021007
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.

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.

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.

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 [ + ]