Continuous Low flow Intermittent High Flow Gas bleed though RB valves

Dual Purge™ System: Variable Level Purge

Specifications Dimensions: 12"W x 11.25"D x 7"H Weight: 16 lbs. Flowmeter: 0-20 SCFH Line Pressure Gauge: 0-60 psi Chamber Sensor: 0 - .4" WG (factory set at 0.02" WG) Inlet/Outlet: .25" (accepts .25" OD polyethylene tubing) Case Material: 304 stainless steel; Chrome plated or stainless steel internal fittings Power Requirement: 110/220VAC, 50/60Hz (requires no manual power setting) Timer Adjustment: 0-8 minutes (factory set at 1 minute)

Dual Purge™ System Variable purge system boosts desiccator efficiency and cuts nitrogen costs.

Cat.# $/Each Control Unit 1606-61 Login Sensor Switch (installed) One per door required 1600-49 Login 0.2 Micron filter Removes contaminants from gas line. 1314-00 Login

Dual Purge™ System

• Cuts nitrogen waste, guards against oxidation
• Ensures a constant positive pressure inside desiccators and other enclosures to block contamination and moisture inflow
• Automatically activates high-flow purge when doors are opened to ensure fast, effective purge of particles and moisture
• Operates in tandem with NitroWatch® to maintain any desired sub-ambient moisture level (down to 0% RH)
• Guards against pressure damage to desiccator doors and seals
• Door switches are highly reliable--rated for over 10 million operations

Desiccators must be continuously purged with nitrogen or another process gas in order to ensure a controlled environment free of contaminants and moisture.

Unfortunately, however, a steady gas inflow can't guarantee the clean, dry conditions you require. A flow adequate to maintain a safe internal positive pressure when doors are closed is insufficient to overcome the backflow of outside air that occurs when a door is opened. A higher-level purge that might guard against this backflow wastes nitrogen and leads to overpressures that warp doors and damage seals.

Dual Purge System Offers Variable-Purge Security
The Desiccator Dual Purge System solves these problems by providing a higher flow level only when it's needed, and only for as long as it's needed.

It relies on a sensor switch installed on each door. During normal operation, with all doors closed, the system maintains an economical low flow of nitrogen into the desiccator to ensure a constant positive pressure of about 0.05" WG (Water Gauge)—just enough to block out moisture and contaminants.

When a door is opened, the sensor switch immediately activates a high-flow purge of nitrogen into the desiccator's plenum chamber that minimizes the influx of moisture and contaminants.

When the door is closed, the high-level gas flow continues to purge the desiccator for a selectable period of time, ensuring that any moisture that does enter the chamber is quickly forced out of the Automatic RB® (Relief/Bleed) Valve, before it can degrade sensitive materials. This time delay is adjustable, so you can retain the high-flow for a longer time when you suspect moisture contamination may have occurred. Note: The Automatic RB® Valve must be ordered separately.

The dual-purge capabilities of these units ensure that contaminants and moisture stay outside the processing chamber and at the same time guard against dangerous overpressures that can lead to warped doors, failed seals--even explosions! And because the Dual Purge System delivers only as much gas as is necessary, it economizes on nitrogen consumption; tests show that in many applications, these units can pay for themselves in a matter of months.

Safety Alarms Ensure Worry-Free Operation
The Dual Purge System incorporates a flowmeter, a line pressure gauge and a variable purge mechanism. A "Low-Pressure" alarm is activated if the incoming line pressure is ever interrupted. This dual audible/visible alarm alerts you to a disconnected supply line, an empty gas storage pod, or other problem that could spell disaster for contents of a desiccator or glove box!

NitroWatch® Controller Expands Capabilities
The Dual Purge System operates in tandem with Terra's NitroWatch® System to fully automate moisture control.

The NitroWatch® includes a humidity sensor that continuously monitors the internal RH level and activates the Dual Purge to automatically maintain any sub-ambient humidity threshold you require (down to 0% RH). For more critical requirements, select the NitroPlex™, which combines this automatic humidity control with multiplexed purge capability. In all of these applications, the Automatic RB® Valve is required to ensure safe relief of overpressures that can build inside a chamber.