Frequent Asked Questions

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Is Cleatech ISO Cleanroom Classification (ISO 5)?

Yes, Cleatech is Cleanroom Classification (ISO5).

Laminar Flow Hoods

What is the purpose of a Laminar Flow Hood?

A Laminar Flow Hood is an enclosed bench designed to prevent the contamination of semiconductor wafers, biological samples, or any particle sensitive materials. The direction of the airflow protects the sample from contaminations. Laminar Flow Hoods are usually made from stainless steel material with no gaps or joints where spores might collect.
Cleatech manufactures horizontal and vertical configuration. Visit our Laminar Flow Hood product page for specifications.

Types of Laminar Air Flow Hoods?

There are two main types of laminar flow hoods, horizontal and vertical. In a horizontal laminar flow hood, clean air moves from a filter located behind the work surface towards the operator. Where a vertical laminar flow hood directs filtered air downwards towards the work surface

Air is filtered with either a HEPA (High-Efficiency Particulate Air) or a ULPA (Ultra-Low Particulate Air) filter.

Laminar Flow Hoods are suitable for a variety of applications where clean air and sterile environment is required. Perfect for medical and research laboratories. Visit our Laminar Flow Hood product page for specifications.

What types of filters are available with your flow hoods?

Cleatech offers two types of filters with our flow hoods.

  • HEPA: 99.99% efficient @ 0.3µm particles
  • ULPA: 99.999% efficient @ 0.12µm particles

Glove Box System

How are Airlocks useful?

To minimize the loss of nitrogen and prevent contamination inflow while parts are moved between chambers, we recommend equipping your glove box with airlocks. These airlocks are mounted to either the left or right side of a transfer chamber.

Watch our video demo

How to clean an Acrylic Glove Box?

Acrylic Glove Boxes can be cleaned periodically with lukewarm water and a clean nonabrasive cloth. A mild nonabrasive detergent may be used if needed. Use light pressure when cleaning your glove box. If the outside surface is exceptionally dirty or gritty, rinse the surface by lightly swabbing a saturated cloth over the unit. Avoid vigorous rubbing as this can damage the glove box. To dry the acrylic surface use a clean, dry cloth and gently blot the surface.

If the inside of a glove box needs to be cleaned, use water and dry the inside surface thoroughly. After the inside is dry purge the cabinet with nitrogen for several hours before reintroducing moisture-sensitive stored materials.

Instructions can also be found on the back of your glove box.


Is Static Dissipative PVC Material resistant to UV light?

PVC (polyvinyl chloride) can block a 254 Nm Ultraviolet Light. The effects of exposure to UV radiation may result in a color change to the product after long-term use.

How does the cycling of inert gas work for a Glove Box?

Nitrogen needs to be introduced to the main chamber and airlock continuously to maintain low oxygen and RH% level (Initial flow rate can be 5 to 20 SCFH and 3 to 5 SCFH to maintain).

Would the Purge Control Unit automatically purge the air lock with Nitrogen with too?

Connecting the outlet of the PCU to the airlocks inlets using a T-Connection (included), the airlocks will be purged continuously with nitrogen at the same time with the main chamber. The Second option is purging the airlock with a spare nitrogen line using a flow meter to control the continuous flow rate separately from the main chamber.

How long should I cycling inert gas into before using the glove box?

The cycle time depends on the level of RH% you want to maintain, ambient level & N2 flow. Our recommendation is 20 to 30 minutes, this is sufficient for many applications.

We have trouble getting the glove box down to <10% humidity. Do you have any recommendations?

Our recommendation

  1. Make sure the nitrogen you are using is fully dry.
  2. Also, as soon as the nitrogen flow is stopped, the RH% and O2 level is increased. You may need to apply nitrogen continuously while you use the glovebox and airlock in order to maintain a low RH%.
  3. Not all Hygrometers can read below 10%RH. Please verify the range of humidity your hygrometer can monitor.

Will the transfer box deteriorate the environment in the glove box? If so, how should we maintain and monitor the environment?

The transfer chamber is used to minimize nitrogen loss and contamination inflow while parts are transferred in and out. An O2 monitor and RH meter can be used to check the environment levels.

What material are the gloves made of? Can other gloves be used?

The material used is Butadyl, an alternative to HYPALON, NEOPRENE or BUTYL. The gloves are a chemical resistant / Anti-static glove with an 8″ diameter cuff port. The gloves can be replaced with any standard 8” dry box gloves. Stainless Steel clamp included and it is compatible with all type gloves.

Desiccator Cabinets

What does the perforated removable plenum do?

In our standard 1500 series desiccators, gas (e.g. Nitrogen) is introduced to the cabinet via a gas-in port on the back plenum chamber and from there distributed to each individual chamber through a perforation back. Gas is purged out to the room through a bleeding valve or gas-out port located in the lowest chamber.

If needed, we can make isolate each individual chamber but one set of gas ports is required for each chamber.

How does a vacuum desiccator work?

A vacuum pump is used to remove air and other gases inside a vacuum chamber. This creates a low-pressure environment within the chamber allowing researchers to conduct experiments inside an environment with low pressure.

Inert Gas and Flowrates

What is the recommended operating pressure for the purge gas and the flow rate?

a) Input pressure for a Purge Control Unit (PCU) is between 15 to 60 PSI

b) The recommended output pressure on the PCU or glove box input pressure is between 5 to 20 PSI that can be adjusted by a pressure regulator on the PCU.

c) The flow rate of a Type-A PCU is set between 2 to 5 SCFH to maintain a low RH%. In order for the initial flow rate to reach the setpoint from ambient RH%, the operator can temporarily increase the flow rate up to 20 SCFH to speed up the process.

d) The flow rate of a Type-B PCU is set between 0 to 5 SCFH. Zero SCFH is used if you don’t require a minimum continuous flow into the glove box. Continuous flow may cause RH% inside the glove box to drop to a lower level than the set point.

How often should we run inert gas through the main enclosure to keep the moisture and oxygen levels to a minimum?

If an Automatic Purge Control unit is not equipped, N2 should be under continuous flow.

What is the cracking pressure for the pressure relief valve?

The cracking pressure for a pressure relives or bleeding valve is 1” WG (inches of water).

How does the purge process works, does the purge gas flow out of the relief valve into the room?

The pressure relief or bleeding valve can be replaced with a standard gas fitting with a 1/4″ NPT thread and connected to the gas-out port to your existing exhaust system, otherwise, it will exhaust to the room.

What are the health risks when working with Nitrogen?

Nitrogen gas is not harmful since the atmosphere is made up of approximately 78% Nitrogen. But increasing the Nitrogen level will reduce the Oxygen percentage in the air. Proper ventilation in a room is recommended.

At what humidity percentage will a silica gel package start to change color?

After 30% absorption, the cartridge will start changing its color.

What is the temperature needed for silica gel regeneration?

Silica Gel cartridges can be regenerated or dried in a conventional oven or microwave oven.

Oven Instructions

  • Place your silica gel cartridge in a glass container
  • Set your oven to 225°
  • Heat for 2 hours

Microwave Instructions

  • Place your silica gel cartridge in a glass container
  • Set the microwave power to the medium to medium-high setting
  • Heat for 2-4 minutes

Safety Tips:

  1. Wear gloves when handling a hot dish
  2. Wear safety goggles

Can silica gel cartridges be reused? And if so, how long are they good for?

Yes, these cartridges can be reused and the self-life is up to 12 months. The process of drying a silica gel cartridge can be done in a microwave or oven.

Does a Purge Control Unit (PCU) require calibration or maintenance?

There is no regular maintenance or calibration needed for a purge control unit. Replace only when experiencing failure with the unit.

For calibration of the sensor, there is an adjust offset screw inside the sensor that can be used.

There is also a “CAL” function on the controller. This function does not recalibrate the sensor but adds a positive or negative offset to the reading from the sensor.

Gas-Ports, Cord grips, etc…

Can I increase the warranty for my unit?

Cleatech-branded products have a 90-day labor warranty and 12 months parts warranty. After the warranty period, you can reach out to our customer support team to help repair or replace the product at the lowest cost possible.

For additional information on our warranty policy, please give us a call at 888-216-8033 or email us at

Please note, for distributed products and the products manufactured by others, the original manufacturer’s return policy and warranty will be followed.

ESD (Electrostatic Discharge)

What is ESD?

ESD or Electrostatic Discharge is created when a sudden flow of electricity between two electrically charged objects come in contact with each other causing an electrical short. This is the results of an imbalance of electrons on the surface of a material. The spark produced through ESD is the major cause of device failure in the semiconductor industry.


Does nitrogen remove moisture?

Nitrogen is the standard inert gas used to force moisture out of a desiccator cabinet. Nitrogen is introduced into the upper section of a desiccator since pushing air out of the bottom of the cabinet. This is achieved because Nitrogen has a lower specific gravity than air.