Hygienic Design – Drainability and riboflavin test of vessels and filter housings

In very hygiene-critical applications such as in the healthcare or food & beverage industry, drainability is of great importance.(gravity drainage). We are happy to support you with a suitable design, for example with special fittings, surfaces with a slope and a roughness of up to Ra ≤ 0.38 µm. We will discuss your test protocol for the drainability of the housing or vessel at the start of your project and consider the current ASME BPE guidelines. We can document the drainability for your end customer with a video we create.

All surfaces that come into contact with the product must either be easily accessible for manual cleaning or it must be demonstrated that automated cleaning in place (clean-in-place CIP) produces compliant results. So-called dead spaces, i.e. areas that are not wetted by the cleaning medium (spray shadows), are particularly feared. CIP lances are often used in containers and filter housings. We are happy to offer you CIP lances with customised spray balls adapted to your application.

To verify the wettability of surfaces in contact with the product, we offer you the so-called riboflavin test. In this test, riboflavin (a fluorescent vitamin) is applied to the product-wetted area, after which a CIP rinse (modelled on reality) is carried out. An UV lamp is then used to check whether fluorescent riboflavin is still present on the surfaces in the filter housing/ vessel. Your advantage with Sommer & Strassburger is our decades of experience in the design, manufacture and documentation of pharmaceutical filter housings and vessels!


Contact us, we can also make your system completely drainable!