SUN HYDRAULICS

Pilot-operated, balanced-piston relief cartridges are normally closed pressure regulating valves. When the pressure at the inlet (port 1) reaches the valve setting, the valve starts to open to tank (port 2), throttling flow to regulate the pressure. These valves are accurate, have low pressure rise vs. flow, they are smooth and quiet, and are moderately fast.

• All 2-port relief cartridges (except pilot reliefs) are physically and functionally interchangeable (same flow path, same cavity for a given frame size).
• Will accept maximum pressure at port 2; suitable for use in cross port relief circuits. If used in cross port relief circuits, consider spool leakage.
• Main stage orifice is protected by a 150-micron stainless steel screen.
• Not suitable for use in load holding applications due to spool leakage.
• Back pressure on the tank port (port 2) is directly additive to the valve setting at a 1:1 ratio.
• Cartridges configured with EPDM seals are for use in systems with phosphate ester fluids. Exposure to petroleum based fluids, greases and lubricants will damage the seals.
• W and Y controls (where applicable) can be specified with or without a special setting. When no special setting is specified, the valve is adjustable throughout its full range using the W or Y control. When a special setting is specified, this setting represents the maximum setting of the valve.
• Corrosion resistant cartridge valves are intended for use in corrosive environments and are identified by the model code suffix /AP for external stainless steel components, or /LH for external zinc-nickel plated components. See the CONFIGURATION section for all options. For further details, please see the Materials of Construction page located under TECH RESOURCES.
• 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.

This FLeX Series solenoid-operated, 2-stage, balanced relief cartridge is a pressure regulating valve. The valve is normally vented. When vented (de-energized), the pressure drop from the inlet (port 1) to tank (port 2) is typically 100 psi.Energizing the solenoid activates the relief function. In relief mode, the valve opens to tank (port 2), throttling flow to regulate the pressure when the pressure at the inlet (port 1) reaches the valve setting. The setting is adjustable with an adjust screw.

• Designed and tested to 10-million operational cycles at full-rated pressure.
• Exceeds new NFPA test standard T2.6.1 R2014 for fatigue and burst pressure ratings.
• Higher flow rates than competing valves of similar size.
• All configurations of this valve include zinc-nickel plating as standard for 1000-hour salt fog protection.
• Coil connector options offer ratings up to IP69K. See individual coil product pages for details.
• This cartridge utilizes both 740 Series high-power and 747 Series hazardous location coils.
• Back pressure on the tank port (port 2) is directly additive to the valve setting at a 1:1 ratio.
• Main stage orifice is protected by a 150-micron stainless steel screen.
• Will accept maximum pressure at port 2.
• All configurations of this valve are assembled with a non-removable adjust screw.
• FLeX Series relief valves are fully compatible with the XMD Expandable Mobile Drivers from Sun.