Pilot-to-close check valve

Capacity: 10 gpm40 L/min. | Cavity: T-163A
COBG : Pilot-to-close check valve
Technical Features [ + ]

This valve is a spring biased closed, pilot-to-close check cartridge that has a 1.8:1 pilot ratio. The valve allows flow from port 1 to port 2 and blocks reverse flow. Pressure at the pilot port opposes pressure at port 1 at a ratio of 1.8:1. This valve is most often used in regeneration circuits.

  • Features hardened steel seats for excellent wear characteristics and contamination tolerance.
  • Product is not available with A and B spring ranges (4 and 15 psi (0,3 and 1 bar)).
  • Nominal pilot ratio is 1.8:1. This means that a pressure of 1000 psi (70 bar) at the pilot port will close a valve against a pressure of 1800 psi (125 bar) at port 1. Any decay or loss of pilot pressure could allow the valve to open, even if it is a momentary decay or loss.
  • Pressure at the port 2 area directly opposes pilot pressure.
  • Reverse flow through the valve from port 2 to port 1 is not possible under any condition.
  • 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-163A
Series 0
Capacity 10 gpm40 L/min.
Pilot Ratio 3.4:13.4:1
Maximum Operating Pressure 5000 psi350 bar
Maximum Valve Leakage at 110 SUS (24 cSt) 1 drops/min.0,07 cc/min.
Valve Internal Hex Size 5/16 in.8 mm
Valve Installation Torque 20 - 25 lbf ft27 - 33 Nm
Model Weight .20 lb0,10 kg
Seal kit - Cartridge Buna: 990163007
Seal kit - Cartridge Polyurethane: 990163002
Seal kit - Cartridge Viton: 990163006
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 [ + ]