The UD series from Ningbo Phen Automation is a compact direct-operated 2/2-way normally closed solenoid valve covering a broad application spectrum across water, air, steam, and oil media. Despite its small footprint, the UD handles pressures up to 3.5 MPa (approximately 507 psi) — unusually high for a direct-operated design — making it suitable for demanding fluid control tasks where pilot-operated valves would be impractical due to minimum pressure requirements.

How do orifice and seal choices determine the application fit?

The UD valve is available with four orifice diameters — 1.2 mm, 2 mm, 2.5 mm, and 4 mm — allowing flow rate to be matched to the application without oversizing the valve. Three seal material options cover the full media spectrum: NBR for standard water, air, and mineral oil service up to 80°C; FKM (Viton) for higher temperatures to 150°C and aggressive or synthetic fluids; and EPDM for steam and hot water where resistance to hydrolysis is essential. The brass and stainless steel body options extend corrosion resistance for washdown, food-contact, and outdoor installations. With coil voltages spanning 12 V to 380 V AC and DC, the UD can be integrated into virtually any industrial control architecture without an intermediate relay or transformer.