Direct magnetic connection opens the seal without needing upstream line pressure. Functions reliably in rough vacuum systems, low-pressure gas, and gravity-fed tanks.

Low-mass stainless armatures execute full travel in 10 to 20 milliseconds, delivering superior volumetric dosing repeatability in high-speed bottling and analytical machinery.

Free of microscopic pilot bypass bleed holes, direct-acting valves tolerate light particulate loads and slightly viscous fluids without the pilot-hole sticking common in pilot valves.

Precision CNC-ground valve seats and resilient elastomer seals ensure zero-bubble shutoff from negative vacuum pressures down to 1.3 × 10^-2 Pa up to 16 bar.

Epoxy-encapsulated Class H (180°C) or Class F (155°C) copper coils endure non-stop, 24/7 energization in enclosed control cabinets without thermal drop-out or coil burnout.

Available in 2-way on/off as well as 3-way universal configurations (Normally Closed, Normally Open, or Diverting) to suit complex OEM instrument manifolds.

Q1: Why is a Direct-Acting Solenoid Valve mandatory for gravity feed and vacuum lines?

Pilot-operated valves rely on upstream line pressure to push open the main diaphragm or piston. If line pressure is zero or negative (such as an atmospheric gravity draining tank or vacuum degassing chamber), there is insufficient hydraulic energy to lift the seal, causing the valve to remain stuck closed. Direct-acting valves use purely magnetic pull to lift the seal, operating independently of line pressure.

Q2: What is the relationship between orifice size and operating pressure in direct-acting valves?

In direct-acting valves, the magnetic coil must overcome the product of line pressure and orifice area (Force = Pressure × Area). Therefore, maximum operating pressure is inversely proportional to orifice diameter. For small orifices (1.0–2.5 mm), the valve can easily hold 1.6 to 5.0 MPa. For larger orifices (6.0–10.0 mm), operating pressure is typically limited to 0.4–0.7 MPa unless a high-power boost coil is fitted.

Q3: What is the functional difference between 2-way and 3-way direct acting solenoid valves?

A 2-way valve has one inlet and one outlet, functioning as a straightforward on/off shutoff control. A 3-way valve features three pipe ports and two internal seats. Depending on port connection, it can serve as Normally Closed (exhausting an actuator cylinder when de-energized), Normally Open, Diverting (routing one inlet to two alternate outlets), or Mixing (blending two inlets into one common outlet).

Q4: How does Delco prevent coil overheating during 100% continuous duty cycles?

Continuous energization can elevate coil temperature and cause insulation breakdown. Delco employs Class H (180°C) and Class F (155°C) enameled copper wire encapsulated in thermosetting epoxy. This provides rapid heat dissipation to the ambient air and prevents moisture absorption, ensuring that steady-state operating temperatures remain well below thermal breakdown limits.