Vent-to-open, spring biased closed, unbalanced poppet logic element with pilot source from port 2

Capacity: 100 gpm380 L/min. | Cavity: T-17A
LOHB : Vent-to-open, spring biased closed, unbalanced poppet logic element with pilot source from port 2
Technical Features [ + ]

These unbalanced, vent-to-open logic valves are 2-way switching elements that are spring-biased closed and have port 2 as a pilot source. With port 3 blocked, the valve will remain in the closed position in the 2 to 1 direction and will function as a check valve from 1 to 2. With port 3 vented, the valve will open provided there is sufficient pressure to overcome the spring force. The force generated at port 3, plus the spring force, must be greater than the sum of the forces acting at port 1 and port 2 for the valve to remain closed. NOTE: The pilot area (port 3) is 1.8 times the area at port 1 and 2.25 times the area at port 2.

  • These valves open quickly when vented. Time to close is difficult to predict as it is dependant on the rate of flow and the pressure drop created as it closes.
  • 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).
  • Corrosion resistant cartridge valves are intended for use in corrosive environments and are identified by the model code suffix /AP (see Option Selection below). The bodies of these valves are made from high strength lean duplex stainless steel. Adjustment screws are made from titanium or silicon brass, depending on the model. Lock nuts, retaining wires, and assorted controls are made from 316 stainless steel. Internal parts are made from carbon steel leaded alloy, the same as standard valves.
  • 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 [ + ]
Cavity T-17A
Series 3
Capacity 100 gpm380 L/min.
Maximum Operating Pressure 5000 psi350 bar
Maximum Valve Leakage at 110 SUS (24 cSt) 10 drops/min.0,7 cc/min.
Pilot Volume Displacement .25 in³4,1 cc
Area Ratio, A3 to A1 1.8:11.8:1
Area Ratio, A3 to A2 2.25:12.25:1
Control Orifice Diameter .031 in.0,8 mm
Valve Hex Size 1 1/4 in.31,8 mm
Valve Installation Torque 150 - 160 lbf ft203 - 217 Nm
Seal kit - Cartridge Buna: 990-017-007
Seal kit - Cartridge Polyurethane: 990-017-002
Seal kit - Cartridge Viton: 990-017-006
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.

Additional Resources [ + ]