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Sun’s new solenoid-operated relief valves join the FLeX Series lineup.

FLeX solenoid-operated relief valves RVC*

New to Sun's cartridge portfolio and to the FLeX Series family, we present four new solenoid-operated relief valves. With a 2-stage, field-adjustable design, they offer precise and dependable pressure regulation with up to 25-gpm (100-L/min) flow rates.

Sun's RVC* valves are the only family of valves on the market that offer fully adjustable, ventable and blockable relief functions. 

The RVC* valves were designed to reduce the complexity and improve the reliability and safety of your systems. 

  • Reduces complexity: these valves combine the functionality of two valves into one body and one cavity, reducing materials and creating a more compact and efficient system.
  • Improves reliability: the main stage orifice is protected by a 150-micron stainless steel screen for extended product life.
  • Improves safety: the adjustment screw is leak-free and contains a mechanical stop to prevent the screw from backing out, offering safe, reliable field adjustment.

RVC* Overview

These are 2-stage, balanced piston reliefs. In relief mode, the valves open to tank (port 2), throttling flow to regulate the pressure when the pressure at the inlet (port 1) reaches the valve setting, which is adjustable. Energizing the solenoid activates or deactivates the relief function. Four versions are available:



Normally vented, energize to relief

Symbol RVCK


Normally in relief, energize to vent

Symbol RVCL


Normally in relief, energize to block

Symbol RVCM


Normally blocked, energize to relief

Symbol RVCN

Designed with applications in mind

Across the board, the unique design of the RVC* family can reduce complexity in mobile and industrial hydraulic systems. The 2-stage design combines two cartridges in one, reducing complexity and overall cost. See an example circuit below, or open the full data sheet for more circuit diagrams.

Ventable RVCK in pump start-up circuit

The RVC* valves are also ideal in fixed-displacement pump applications. Each model in the RVC* valve family presents a distinct advantage to specific hydraulic systems and applications. 

  • RVCK - Use for pump start-up to unload until pressure is built, eliminating stress on the system, then energize during operation. 

  • RVCL - Allows the user to energize at start-up and de-energize during operations to keep power consumption lower during use.

  • RVCM - Ideal in circuits that require two pressure settings, one with a high setting at acceleration, and one with a setting that is constant. The blockable RVCM regulates pressure throughout. 

  • RVCN - Use the relief function to preload the cylinder and avoid decompression shock in systems built for high capacities. 

Applying the RVC* in specific hydraulic systems is explained further in the full data sheet, complete with circuit diagrams. Click here to download.

The FLeX Advantage

These solenoid-operated relief valves add to the existing FLeX Series of directional control valves and proportional flow control valves. As we continue to grow our FLeX Series, the same goal remains – to provide high-performance solutions at market prices.

Like the other FLeX products, these new relief valves offer the same quality, durability and cost-competitiveness.

FLeX Logo
  • High reliability - designed and tested to 10-million operational cycles at full rated pressure

  • Zinc-nickel plating standard for 1000-hour salt fog protection

  • Interchangeable coil options - uses the 740 Series high-power and 747 Series hazardous location coils in a range of coil terminations and voltage options

  • High performance - available in 15-gpm (60-L/min) and 25-gpm (100-L/min) nominal flow rates

To view entire FLeX product overview document, click here.  

740 Series High-Power and 747 Series Explosion-Proof Coils

740 Series and 747 Series coils

The RVC* utilizes both 740 Series high-power and 747 Series hazardous location coils. A wide variety of coil termination and voltage options are available, with and without surge protection.

740 Series High-Power Coils

    • 740 Series comes in 12, 14, 24, and 28 Vdc and 115 and 230 Vac
    • DIN 43650 Form A (IP65/IP67 rated) and Deutsch DT04-2P (IP69 rated)
    • Transient voltage suppression (TVS) diode is optional for dc coils and standard for ac coils

Download the full data sheet: 740 Series Coils.

747 Series Hazardous Location (explosion-proof) Coils

    • 747 Series offers ATEX, IECEx and CSA global certifications
    • Certified for gas and dust environments (T4 compliant for gas, T135°C for dust)
    • CE compliant
    • 30-W coils come in 12- and 24-Vdc and 115- and 230-Vac options
    • DC coils have integral TVS diode and offer 48-Vdc breakdown voltage
    • AC coils are internally rectified
    • 90° and 180° connector options with either 1/2" NPT or M20 x 1.5 female thread for electrical connections

Download the full data sheet: 747 Series Coils.

Incorporate FLeX into your design

Sun's performance-driven, market-priced FLeX Series relief valves are unlike any in the market. Contact your local distributor to incorporate them into your design and improve the efficiency and reliability of your systems. 


Download the FLeX Series Overview Document.
Download the RVC* Full Data Sheet, which includes circuit examples.
Visit the FLeX relief valve product pages.