RTP vs. CRTP – What’s the Difference?

CRL Rapid Transfer Port

Rapid Transfer Ports (RTP) have been around for several decades, finding initial use in nuclear gloveboxes. CRL developed one of the first Double Door Transfer Systems for this industry in 1972. Since then, Transfer Ports have evolved in design, however functional operation remains much the same. In recent years, these ports have seen growing usage in the pharmaceutical industry for various aseptic manufacturing applications.

CRL Rapid Transfer Ports (or Alpha ports) are commonly used in applications to transfer sterile or hazardous materials into or out of containment. The transfer system consists of two main components, the Alpha assembly and the Beta assembly, each with a door, seal, and interlock function. The interlock system helps to ensure a safe, reliable connection and operation. To engage the interlocks and open the Alpha door, a Beta assembly must be attached and properly connected. Likewise, the Beta can’t be disconnected until the Alpha door is properly closed and locked. When the two assemblies are mated, materials can be rapidly transferred into and out of isolation without breaking containment.

CRL offers two versions of this Alpha port. The right one for your application is dependent on several factors, but we find that industry usage is the most common consideration when choosing an Alpha port.


RTP Overview

Rapid Transfer Ports  are typically used for nuclear and all other processes where cleanliness isn’t critical. Most often hazardous materials are being transferred into a glovebox or removed for proper disposal. A noticeable difference between the two is with the design of the handle. The RTP handle also rotates 180 degrees and is not attached to the door.

CRTP Overview

Clean Rapid Transfer Ports (CRTP) are typically used for pharmaceutical production which requires sterility to be maintained throughout the process. This port operates the same as an RTP, leveraging interlock functionality to help prevent contamination and ensure reliability. The main difference between these two ports is the streamlined design of the CRTP. It features smoother surfaces for easier cleaning, fewer exposed fasteners, and reduced pinch points that could puncture a glove. The CRTP handle also features a smoother surface and requires minimal rotation, reducing operator effort.

CRL Alpha ports come in standard sizes of 105, 190, 270, and 350 mm. Standard construction is stainless steel with door options in either stainless steel or polypropylene. A liquid transfer door is also available on both versions, allowing for streamlined transfer of sterile liquid into a contained environment. Various Beta assembly options in a range of sizes and materials are available to accommodate all your application needs. More information about our Betas can be found here: https://crlsolutions.com/products/transfer-systems/beta-assemblies/

If you have questions about either option or any CRL solution, contact us to discuss your needs. We’re happy to help determine the right fit and configuration for you.