Pilot-to-close, spring biased closed, unbalanced poppet logic element with position switch

Capacity: 50 gpm200 L/min. | Cavity: T-2A
LOFCZ : Pilot-to-close, spring biased closed, unbalanced poppet logic element with position switch
Technical Features [ + ]

These unbalanced, pilot-to-close logic valves are 2-way switching elements that are spring biased closed. Pressure at either work port 1 or 2 will oppose the spring and tend to open the valve while pressure at port 3 will tend to close it. The force generated by the pressure at port 3, plus the spring force, must be greater than the sum of the forces generated by the pressures at ports 1 and 2 for the valve to remain closed.

This valve incorporates a position switch to provide confirmation that the valve is closed.

  • The position switch in this valve provides confirmation that the valve is closed.
  • These valves have positive seals between port 2 and the pilot area.
  • This cartridge is supplied as a sealed, factory set unit and is not field serviceable. Any tampering will violate the product warranty.
  • When torquing this cartridge into its cavity, a crow's foot wrench or similar will be required since the position switch precludes the use of a deep socket wrench.
  • Because these valves are unbalanced, operation is pressure dependent. Opening and closing of the poppet are functions of the force balances on three areas: Port 1 = 100%, Port 2 = 80%, and the Pilot Area = 180%.
  • These valves are pressure responsive at all ports, therefore it is essential to consider all aspects of system operation through a complete cycle. Pressure changes at any one port may cause a valve to switch from a closed to an open position, or vice versa. All possible pressure changes in the complete circuit must be considered to assure a safe, functional system design.
  • All ports will accept 5000 psi (350 bar).
  • Position switch is CE approved.
  • An optional protective cover, with mounting hardware included, may be ordered separately. See kit number: 991-043.
  • 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-2A
Series 2
Capacity 50 gpm200 L/min.
Maximum Operating Pressure 5000 psi350 bar
Maximum Valve Leakage at 110 SUS (24 cSt) 1 drops/min.0,07 cc/min.
Pilot Volume Displacement .07 in³1,1 cc
Pilot Passage into Valve .035 in.0,9 mm
Area Ratio, A3 to A1 1.8:11.8:1
Area Ratio, A3 to A2 2.25:12.25:1
Transition leakage at 110 SUS (24 cSt) 2 in³/min.@1000 psi30 cc/min.@70 bar
Valve Hex Size 1 1/8 in.28,6 mm
Valve Installation Torque 45 - 50 lbf ft61 - 68 Nm
Seal kit - Cartridge Buna: 990202007
Seal kit - Cartridge Polyurethane: 990002002
Seal kit - Cartridge Viton: 990202006
Switch Specifications [ + ]
Note: Data may vary by configuration. See CONFIGURATION section.
Supply Voltage 20-30 VDC20-30 VDC
Operating Temperature Range -25 to 80 °C-25 to 80 °C
Vibration ≥ 50g, 0-500 impulses/sec≥ 50g, 0-500 impulses/sec
Shock >50 g, 1ms>50 g, 1ms
Reverse Polarity Protection YesYes
Maximum Output Load ≤ 400 mA, Duty Ratio 100%≤ 400 mA, Duty Ratio 100%
Short Circuit Protection Yes, Load Short UnlimitedYes, Load Short Unlimited
Turn On Time ≤ 25 ms≤ 25 ms
Hysteresis ≤ .002 in.≤ .002 in.
Thermal Shift - 0 to 80 °C ≤ ± .004 in.0,1 mm
EMC DIN EN 61000-6-1/2/3/4DIN EN 61000-6-1/2/3/4
Connector M12 X 1 (4) PinM12 X 1 (4) Pin
Connector Environment Rating IP65IP65
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.

Additional Resources [ + ]