Choosing a Hygienic Fitting 

What are Hygienic Components?

Hygienic Tubes and Fittings are specifically designed for applications where there is a requirement for the internal surfaces of the pipes to be cleanable. They are produced with internal surfaces which are smooth and do not have obstructions or crevices that could capture the product and subsequently cause contamination. These requirements are typically present in the food processing, dairy, brewing, pharmaceutical and many other hygiene critical industries. They are also often used as an economic stainless steel piping system in many other industries.

Types of Hygienic Fitting

In the UK and Ireland there are a number of different types of hygienic fittings used. These include the fittings identified in British Standard BS4825 Parts 2 to 5. (EN20286) which covers RJT, IDF and clamp fittings. There are other British hygienic unions that are used occasionally including SRJT  (similar to RJT but for larger sizes) and ILC (a union developed for CIP purposes).

Other American and European hygienic standards are also sometimes used. These include DIN 11850 to 11852, US 3A, SMS and DS.

Hygienic Tubes

ASTM A 249, A 269 and A270 are the most commonly used manufacturing standards for hygienic tubes. The tube is provided with the internal weld bead removed or flattened. The internal finish and external finish can be specified (as seen, for example, in the ASME BPE standards).

Materials

Most hygienic tube and fittings are available in grades 304L and 316L.

Sizes

The union size denotes the outside diameter (or OD) of the pipework. Common sizes in use range from ½ inch to 4 inch. Larger sizes are available in some types of fitting. In Europe , most of the fittings are metric sizes, and these are sometimes used in the UK and Ireland .

System Pressures

Most hygienic fittings are rated for low pressure use, typically up to 10 bar, however there are higher pressure hygienic fittings system available up to 100 bar+.