Conforms to VDI/VDE 3845 NAMUR mounting standards, bolting flush onto actuator air supply pads without external mounting brackets, fittings, or nylon air tubes.

A simple 180-degree rotation of the included interface gasket converts the valve from 5/2-way (double-acting) to 3/2-way (spring-return fail-safe), slashing inventory requirements.

High-efficiency electromagnetic magnetic circuits draw as little as 2.5W to 4.5W, allowing direct digital control from PLC transistor outputs without costly interposing relays.

A precision-machined, hard-anodized aluminum spool with low-friction HNBR O-rings executes directional switching in 15 to 30 milliseconds with zero stick-slip hesitation.

Features a recessed push-and-turn manual override button on the pilot body, facilitating straightforward mechanical commissioning, stroke testing, and emergency actuation.

Exhaust ports feature threaded connections fitted with sintered bronze/stainless steel breathers or piped exhaust lines, preventing ambient moisture and dust ingress into the actuator.

Q1: How does a single NAMUR valve convert between 3/2-way and 5/2-way operation?

Delco NAMUR valves include a precision reversible interface plate fitted between the valve body and the actuator pad. When set to the 5/2 position, both actuator ports (A and B) are pressurized/exhausted for double-acting actuators. Rotating the conversion plate 180 degrees transforms the internal porting into a 3/2-way configuration, directing air to port A while venting spring-side port B through an internal breather channel for spring-return actuators.

Q2: What is the technical advantage of direct NAMUR mounting over piped solenoid valves?

Traditional piped valves require custom sheet-metal mounting brackets, threaded pipe nipples, and coiled nylon tubing. This increases installation labor, creates potential air leak points, and introduces vibration failure risks. The standard NAMUR VDI/VDE 3845 footprint bolts directly to the actuator casing with two O-rings, providing a compact, vibration-proof, leak-free assembly.

Q3: When should engineers specify a 5/3-way valve instead of a standard 5/2-way valve?

Standard 5/2-way valves have two active states (fully open or fully closed). A 5/3-way valve features two solenoid coils and three distinct positions. When both coils are de-energized, internal centering springs return the spool to the middle position. Closed-Center (APB) spools trap air in both actuator chambers, locking the valve disc in an intermediate position for throttling or emergency holding. Exhaust-Center spools vent both chambers, allowing manual free-wheeling.

Q4: Can Delco pneumatic directional valves operate reliably on unlubricated compressed air?

Yes. Modern automated facilities frequently mandate oil-free air to prevent ambient environmental contamination. Delco’s valve spools are micro-finished and hard-anodized, paired with self-lubricating HNBR and polyurethane lip seals pre-treated with synthetic high-stability grease, certified for over 2 million cycles on clean, dry, unlubricated instrument air.