Custom Cleanroom Pass-Thrus
Pass-thrus are an important piece of equipment used in many cleanroom environments. They make transfer of materials between cleanrooms and the outside environment much easier, while also not allowing dirty air to enter the area. Instead of having to leave the cleanroom every time you need something, pass-thrus make it possible to transfer items without having to go through decontamination every time.
Liberty Industries has a variety of standard and custom pass-thrus for any of your cleanroom needs. For more than six decades, Liberty Industries has been a global expert and industry leader in cleanrooms and contamination control, including products such as our pass-thrus. For whatever application or special design consideration you need, we can help find the custom solution for you. We have a history of excellence serving various industries, from aerospace to pharmaceutical to precision manufacturing, and we understand the unique implications of cleanroom classifications and regulations in applications across these diverse spaces.
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What Are Pass-Thrus for Cleanrooms?
A pass-thru—also known as a pass-thru chamber, cabinet, or window—is a two-door, airlock compartment that is used to transfer materials between a cleanroom environment and another space without depressurizing the cleanroom, allowing dirty air to enter the area, or otherwise compromising the air quality.
Floor- or wall-mounted pass-thru enclosures utilize a set of interlocking doors to prevent the cleanroom and uncontrolled environments from accessing the transfer cabinet at the same time. Because cleanrooms rely on filtered, positive pressure air to regulate particulate presence and maintain environmental purity, pass-thrus are a critical component in minimizing contamination risk and preserving the cleanroom environment.
Pass-thrus can increase cleanroom productivity and ensure environmental sterility. They do this by reducing the need for human traffic entering and exiting the space—which cuts down on time and materials costs related to putting on a gown and showering—and protecting the cleanroom environment from exposure to unfiltered air and damaging contaminants. They are affordable, simple to install, and easy to maintain. Pass-thru chambers can be customized to meet the industry standards required for any cleanroom environment, allowing for modifications to size, material construction, and added safety features like high-efficiency filters and fire-rated doors.
Interlocking Systems: Mechanical vs. Electric
One of the most important purposes of a pass-thru is to transfer materials from outside, without contaminating the cleanroom itself. This makes the interlocking system essential, as it prevents both doors from opening at the same time. These safety mechanisms are put in place to ensure USP 797 compliance and reduce contamination.
Mechanical interlocks involving stainless steel rods are very reliable and do not require power (in case of an outage, this can be very helpful). They are often more cost-effective as well and require less maintenance. Electronic interlocks on the other hand usually involve elements like sensors or magnets to keep the doors closed. These are often preferred for higher-contamination areas and higher-end facilities as they are harder to manipulate. They can also be programmed with programming to fit in with an entire security system.
Common Pass-Thru Materials
Oftentimes, the most reliable material for a pass-thru is stainless steel as it is corrosion-resistant and used in many sterile environments. Certain alloys of stainless steel are also resistant to more corrosive elements and chemical reactions. The most popular alloys used for pass thrus include 304 stainless and 316L. Electropolishing is also a popular finishing service as this can remove contaminants from the surface and leaves a nice mirror finish. Plastics are also a popular choice as many plastics, such as polypropylene, are very sturdy and also resistant to elements.
Filtration for Pass-Thrus
While some pass-thrus simply rely on the internal pressure of a cleanroom to keep contaminants out, for applications that require higher filtration, HEPA and ULPA filters are very often paired with pass-thrus to achieve up to 99.99% filtration.
Wall Mount vs. Floor Mount Pass-Thrus
Wall-mount pass-thrus are more common; they are installed into the wall of a cleanroom and function as a kind of cabinet where smaller parts (tools, samples, equipment) can be passed into the room. Floor-mount pass-thrus are much larger and more suitable for heavy and large equipment.
Our Products Available to Buy for Cleanrooms
Liberty Industries offers several pass-thru models designed to accommodate the needs of diverse cleanroom applications across a range of industries. Many of these products are either ready to buy, or can be customized to your specific industry needs. Our product line includes:
- H-100SS Stainless steel pass-thrus are constructed from 304 #4 stainless steel with acrylic viewing windows and stainless steel hinges. They can be customized to include an interlocking system, fire-rated doors and motorized with HEPA filtration, uses high-velocity air wash and high-efficiency filters to achieve 99.99% filtration. Stainless steel pass-thrus can also be manufactured in a variety of sizes to meet the needs of any application.
- H-100SSEML Stainless steel pass-thrus with magnetic interlocks offers advanced security to ensure quality in sterile environments such as hospital pharmacies. These 304 #4 stainless steel cabinets use a magnetic interlocking mechanism to prevent cleanroom and exterior doors from being opened simultaneously to prevent cross-contamination or depressurization. We offer the option of motorized w/ HEPA filtration; uses high-velocity air wash and high-efficiency filters to achieve 99.99% filtration. Manufactured in a variety of sizes to meet the needs of any application.
- H-100 PL Laminated pass-thrus feature novaply high-pressure laminated plastic with acrylic doors and chrome-plated hinges to ensure protection from contaminants. A stainless steel interlock system can be added to the chamber for additional security. Manufactured in a variety of sizes to meet the needs of any application.
- Motorized HEPA/ULPA-filtered pass-thrus uses a high-velocity air wash and high-efficiency filters to achieve 99.99% filtration. They are manufactured using durable laminated novaply, stainless steel, or CRS, and can include fire-rated doors, air recirculation, and perforated stainless steel shelves. Manufactured in a variety of sizes to meet the needs of any application.
Pass-thru chambers play an essential role in maintaining your cleanroom environment’s quality and cleanliness standards by allowing for the safe transfer of materials between the cleanroom and uncontrolled exterior spaces. By limiting the frequency with which personnel need to enter the cleanroom space, these airlock chambers minimize potential exposure to contaminants while improving operational efficiency and promoting product integrity.
As a manufacturer and distributor of cleanroom and contamination supplies for more than 60 years, our team at Liberty Industries understands the importance of every component and piece of equipment that goes into your cleanroom environment. We are a Made in America company, meaning we can help with any supply chain or lead time issues, in addition to offering a high-quality product.
To learn more about our pass-thru systems, discuss the customizations needed for your application, or find out how our products and services can improve your cleanroom environment, contact us, or request a quote today.
