NO Water Valve with Housing Lely

Water Valve NO with Housing for Lely Astronaut

The Water Valve NO (Normally Open) is a specialized solenoid valve assembly used in the fluid manifolds of Lely Astronaut A2, A3, and A4 robots. Unlike the more common NC (Normally Closed) variants, this "Normally Open" valve remains in the open position when power is removed. This is a critical safety and functional design choice for specific rinsing or drainage paths within the robot's internal plumbing.

Product Specifications

Key Features

• Safety Default: In the event of a power failure or emergency stop, this valve defaults to the open position. This is often utilized to ensure lines are drained or to provide a "fail-safe" bypass for water flow.
• Integrated Protective Housing: The solenoid coil and electrical terminals are fully enclosed in a rugged housing, protecting the sensitive electrical components from the high-moisture, high-alkaline environment of the milking stall.
• Rapid Response: Engineered for high-frequency cycling during the robot's cleaning and rinsing phases (CIP).
• High-Grade Seals: Internal diaphragms are made from chemical-resistant elastomers, designed to withstand both hot water and acidic/alkaline cleaning solutions.

System Application

In the Lely manifold blocks, the NO (Normally Open) valve is typically used for:

1. Drainage Lines: Ensuring the manifold can empty completely to prevent stagnant water or bacterial growth.
2. Vacuum Interruption: Acting as a vent to break vacuum pressure during specific phases of the milking or cleaning cycle.
3. Steam/Water Bypass: Used in the Pura steam sterilization system to manage pressure relief.

Maintenance Insight

Because this valve is Normally Open, it requires constant electrical current to stay Closed.

• Heat Check: It is normal for the housing of an NO valve to feel warmer than an NC valve, as the coil is energized for longer periods during the robot's idle state.
• Failure Mode: If you notice water constantly running into the drain or out of the arm when the robot is supposed to be cleaning, the valve may have lost power or the internal plunger may be stuck in its default open position.
• Scale Buildup: As with all water valves in the Lely system, mineral deposits (calcium) can prevent the plunger from sealing tightly against the seat when energized.