2KL - Direct-acting Normally Open Type
When "Power-Off" Means "Must-Flow": The AirTAC 2KL Normally Open Valve
In industrial design, we instinctively equate "safety" with "stopping." On power failure, we want valves to shut and actuators to retract. But what happens when the safe state is the exact opposite? In critical cooling loops, fire suppression, or emergency purging, a power outage must trigger a Fail-Open response to prevent mechanical seizure or vessel explosion.
The AirTAC 2KL Direct-Acting, Normally Open (NO) series is the enforcer of this safety philosophy. It is a purpose-built survivor for harsh media—specifically high-temperature water and steam—ensuring that when the power goes dark, your critical flow does not.
- Fail-Safe Open Logic: Default de-energized state is OPEN. Power is required only to close the flow path.
- Direct-Acting (Zero MOPD): Operates flawlessly at 0 psi, under gravity-feed, or in vacuum lines.
- Triple-Proof Material Shield: SUS304 Stainless Steel body + PTFE (Teflon) seals + Class H high-heat insulation.
- Steam Mastery: Officially rated for saturated steam up to 183°C (361°F).
- Energy-Saving Default: Consumes zero power in its primary "open" state, preventing coil heat-wear in constant-flow systems.
1. The Direct-Acting Advantage: Zero Pressure Start
The 2KL's core differentiation lies in its mechanical architecture. In this direct-acting model, the solenoid coil serves as the exclusive muscle of the valve.
Power-OFF (Default Open)
A precision internal spring pulls the plunger away from the seat, maintaining a clear flow path. The coil remains cold and de-energized.
Power-ON (Actuated Closed)
The coil generates a magnetic force that overcomes the spring, seating the plunger and sealing the valve shut.
⚠️ THE PILOT TRAP:
Larger valves (2KL150+) are "Internally Piloted" and require a Minimum Operating Pressure Differential (MOPD) of 7-10 psi to function. If you install a pilot valve on a gravity-feed tank, it will fail. The 2KL030/050 Direct-Acting units are mandatory for vacuum or zero-head pressure tasks.
2. Material Science: Surviving 183°C Steam
The 2KL series is a specialized "tank" built to conquer the primary failure modes of steam control: corrosion, seal swelling, and coil burnout.
SUS304 Stainless Shield
A massive upgrade from brass, providing superior resistance to atmospheric corrosion and high-temperature oxidation in industrial boiler rooms.
PTFE "Anti-Steam" Seal
Unlike FKM (Viton) which swells in steam, PTFE (Teflon) is chemically inert and handles the 183°C thermal load with a massive safety margin.
Class H Insulation (180°C)
The coil must fight a "triple heat load": self-electrical heating + media heat conduction + ambient heat. Standard coils burn out; Class H survives.
3. The Pressure vs. Flow Trade-Off
In direct-acting valves, the coil must physically fight the fluid pressure. This is governed by the mechanical relation:
$$Force_{coil} = Pressure \times Area_{orifice}$$
2KL 030 Series (Precision)
Standard: 3.0mm orifice (0.33 Cv) handles 100 psi.
High-Pressure (2KLH): Orifice shrunk to 2.0mm to fight 220 psi.
2KL 050 Series (Volumetric)
Standard: 5.0mm orifice (0.83 Cv) handles 100 psi.
High-Pressure (2KLH): Orifice shrunk to 4.0mm to fight 220 psi.
Technical FAQ
Can I use this for Acetone?
Yes. Because the 2KL utilizes PTFE (Teflon) seals and SUS304 metal, it has near-universal chemical compatibility, unlike NBR or Viton valves.
Does "Normally Open" use more energy?It depends on your duty cycle. For cooling systems that run 90% of the time, the 2KL is OFF 90% of the time. This saves thousands of kilowatt-hours annually compared to a standard NC valve.
Unstoppable Reliability
The AirTAC 2KL Direct-Acting, Normally Open series is the professional’s choice for systems where flow is the definition of "safe." By combining zero-pressure startup capability with the high-thermal armor of SUS304 and PTFE, it provides the definitive answer for high-stakes steam and cooling applications. For unstoppable flow when the power fails, the 2KL is the only engineered answer.