How should new MS flareless tubing/fittings be assembled?

Assembling new MS flareless tubing and fittings should be done in a clean and dry state to ensure reliable performance and prevent contamination. Flareless fittings are designed to create a secure seal without the need for lubrication or additional connectors, which could introduce contaminants or affect the integrity of the connection.

When the tubing and fittings are clean and dry, there is a better likelihood of achieving the proper compression and seating of the components, leading to a leak-proof assembly. Any oils, dirt, or moisture can interfere with the proper fit and may compromise the function of the fitting, potentially causing leaks under pressure.

The other methods, such as using heat treatments or lubrication, are generally not recommended for flareless fittings as they could lead to distortion or improper fitting engagement. These types of fittings rely on the mechanical compression of the tubing against the fitting and do not benefit from additional treatments that might alter their material properties.