Types

• Type D: with female thread

• Type E: with threaded stud

• AISI 316 L (A4)

• matte (Ra < 0.8 µm) MT

• polished (Ra < 0.8 µm) PL

Sealing ring

Hydrogenated acrylonitrile butadiene rubber (H-NBR) H

temperature resistant -25 °C to + 150 °C

Ethylene propylene diene rubber (EPDM) E

temperature resistant -40 °C to + 120 °

• blue

• Hardness 85±5 Shore A

• FDA compliant

GN 75.6 Stainless Steel-Waist shaped knobs are inteded for use in hygienic areas. The sealed mounting surfaces enables mounting without dead spaces; the impervious geometry in combination with the high quality finish prevents the accumulation of dirt and facilitates cleaning.

GN 75.6 Stainless Steel-Waist shaped knobs have a compact and timeless design.

• Stainless Steel characteristics 

Why Hygienic Design?

Advantages of Hygienic Design

• more time available for production

• less fresh water consumption

• lower energy consumption

• less cleaning agent required

• less production of waste water

• lower total costs and saving of resources

Legal basis of Hygienic Design

EN 1672-2:2009 “Food machinery”

Machines must be able to be cleaned, i.e. they must be designed and constructed so that dirt can be removed with the recommended cleaning methods.

Machinery directive 2006/42/EC

Machines must be designed so that

• materials can be easily and fully cleaned before each use and

• no risk of infections or illness is created.

DIN EN ISO 14519:2008-07

Hygiene requirements for the design of machines

DIN EN 1672:2009-07

Food machinery – General design principles – Part 2

Design requirements for Hygienic Design

• Non-rusting Stainless Steels

• FDA and EU compliant plastics and elastomers

• Surfaces must be able to be cleaned

• Steps due to appliance configurations which are not aligned must be avoided

• Seals must be designed so that no gaps occur

• O-ring grooves must be hygienically designed

• Contact with the product to be manufactured must be ruled out

• Corners should preferably have a radius of 6 mm or more

Design / Geometry

The interior and exterior areas of all appliances, components or piping must be self-draining or be able to be drained and easy to clean.

Surface properties and roughness

Easy to clean with Ra < 0.8 μm

 

Design principles for Hygienic Design

• European Hygienic Engineering & Design Group

• non-profit European consortium of machine and food manufacturers as well their suppliers, research institutes, universities and government health agencies

• approximately 45 guidelines

• examination of products and issue of certificates

• non profit and independent association in the USA

• three interest groups:public and governmental health agencies, machine and food manufacturers

• over 70 Sanitary Standards

• examination of designs and processes, issue of certificates

Seals

A fundamental differentiation can be made between static and moving seals:

Is the static seal, application examples shown below the top faces the mounting surface (sealing ring) and the bottom faces the contact surface (bottom seal), so that the corresponding pressure is achieved by tightening. It should be ensured that all surfaces which make contact with the seal have a surface finish of al least Ra 0.8 µm.

The moving seals on the adjustable sleeve (wiper) and the ball joint (joint sealing ring) of the foot are designed so that they allow adjustment in both height and angle. With these too, the installation space together with the cross section of the seal ensures a gap-free, pre-tensioned seal.