A New Generation Dosing Pistons

ULMAN Dichtungstechnik has developed a new generation of dosing pistons for filling liquid and paste-like media in the food and pharmaceutical sectors.

Dosing pistons often utilize a glide ring design derived from hydraulics or pneumatics. These systems only comply with hygienic design guidelines to a limited extent. This means that, despite careful cleaning, contaminants can accumulate in the gaps. Even if the system is sterilised, it is impossible to prevent contaminants from ending up in the medium being filled.

As this problem is inherent in systems using a sliding ring seal, ULMAN has developed a closed-seal design. The focus here was on hygienic design without gaps or recesses.

ULMAN dosing piston features a gap-free design. It features a flexible sealing lip which achieves the required seal through an integrated preload element. This ensures the required hygienic design is achieved without gaps or undercuts. In addition, a bayonet mount has been incorporated for installation. This significantly reduces assembly time and the time taken to replace individual pistons compared to the screw-mounted dosing pistons previously in use.

In addition to the standard geometry, customised versions are also available. There are options for customisation in terms of design, dimensions, choice of material, preload element and seal lip mounting - these details should be discussed with our technical team.

Our dosing piston can be used to adapt an existing solution featuring a steel piston and sliding ring. The housing and cover of our dosing piston are made of stainless steel.

Depending on the requirements, the Ulman dosing piston can be adapted to the specific conditions through the selection of materials. Our product range includes various PTFE compounds and UHMW-PE, all of which are FDA-compliant.

Depending on the requirements and the material used, the ULMAN dosing piston can be used for CIP (Cleaning in Place) up to approx. 80°C or SIP (Sterilisation in Place) steam sterilisation up to 140°C. This depends on the material of the dosing piston used. When using a PTFE compound, both cleaning methods are possible. However, if you use a dosing piston made of UHMW-PE, only CIP cleaning is possible.

The UHMW-PE dosing piston is more abrasion-resistant than a piston made from a PTFE compound.

In principle, the selection of materials and the design of the seal geometry are carried out in collaboration between users and the technical advisers at Ulman Dichtungstechnik GmbH. Consequently, ensuring that the optimal solution is found for virtually any application.