ASCO Series 256/356 High-Pressure Solenoid Valves

April 12, 2021

Emerson has launched a range of two-way and three-way solenoid valves that support OEMs' need to develop more compact machines and equipment without compromising on fluid control performance. The body design and internal flow path of the ASCO Series 256/356 provides a smaller footprint, reduced power consumption, and increased pressure ratings.


The reduced footprint of the series helps OEMs optimize the internal layout of their equipment, enabling more high-performance fluid control options to be integrated into a smaller and sleeker final product. This is especially important for manufacturers of coffee machines and other beverage dispensers; heating, ventilation, and air conditioning; pumps and compressors; welding equipment; and analytical and medical devices.


Achieving comparative pressure ratings in a smaller valve typically results in increased power consumption, but the Series 256/356 reduces energy use by as much as 40%. This enables OEMs to apply a smaller valve while matching or improving on the fluid control performance of the previous version and make significant energy savings.


The pressure rating of some versions of the redesigned Series 256/356 has increased by up to 30% compared to the previous versions, enabling them to be used in more demanding applications, such as high-pressure washers and hydrogen fuel dispensers. The performance of the DC voltage version is now similar to that of the AC voltage version, enabling overall system costs to be reduced by eliminating the need to convert to AC power to maximize solenoid valve performance.


The series offers an expanded selection of body materials, including lead-free brass, stainless steel, and an engineered composite material that is 20% lighter than brass and meets global health and safety standards for food and beverage applications. The valves are dust-tight, IP67-rated, and submersible in up to one meter of water, making them suitable for harsh environments, increasing reliability, and extending the life of machinery.


The Series 256/356 has multiple end-connector options and flexible electrical connections for easy installation.




Valve ActuationSolenoid Direct ActingBody Material

Brass; Stainless Steel;
Composite (PPS)

Stainless Steel

Media Oxygen,
Hot WaterAir, Inert Gas, Light Oil, WaterPipe/Port Size1/8 in.; 1/4 in.; Pad-MountPort TypePush-to-Connect;
(Compression Fitting)


NPTF, G-Thread, Pad-MountFunction2 way - 2/2 Normally Closed
or Normally Open3 way - 3/2 Normally Closed
3 way - 3/2 Normally Open
3 way - 3/2 UniversalFlow0.05 to 0.48 Kv
(0.06 - 0.55 Cv)0.05 to 0.4 Kv
(0.06 to 0.46 Cv)Voltage 100 to 240 AC/DC Voltage Ranging,
12, 24, 48 DC | 50, 50/60, 60Max Differential/
Max Operating PressureVacuum to 10.3 Bar;
Vacuum to 150 PSIG 10.3 to 34.5 Bar | 150 to 500 PSIGOperating EnvironmentIndoor to IP67 (EN 60529) Standards/RegulationsCSA; IP67; NSF; UL 

Features for 256:

  • Quick connect options for fast installation
  • AC/DC interchangeability of the solenoid and rotatable coils.
  • Subminiature NSF 61 Annex G and 169 versions with 316L stainless-steel, lead-free brass, and composite (PPS) constructions are available for potable water and food service
  • Gas combustion models are available for industrial and commercial gas burner controls. The valves incorporate direct lift with resilient soft sealing for tight shutoff
  • Fuel Oil combustion versions are available for industrial and commercial burners that use No.2 or No. 4 fuel oil
  • UL-recognized and CSA-certified for application across a range of industries
  • Satisfy all relevant EU directives

Features for 356:

  • Reliable, proven compact design for long service lifetimes
  • Standard manual operator allows easy installation
  • Mountable in any position
  • Valves do not require a minimum operating pressure
  • Wide range of flow and pressure ratings are available
  • Quick disassembly of core tube for easy maintenance of internal parts