Plunger piston

for the food industry

Overview
ULMAN Dichtungstechnik has developed a new generation of dosing pistons designed for hygienic filling of liquid and paste-like media in the food and pharmaceutical sectors. The design eliminates gaps and undercuts to minimize contamination risk during filling and cleaning.

Problem addressed
Conventional dosing pistons with sliding/glide ring seals (from hydraulic or pneumatic designs) often feature gaps and recesses that can trap residues. These areas may retain contaminants even after cleaning or sterilisation, posing a risk to product hygiene. The ULMAN solution uses a closed-seal, gap-free hygienic design to prevent such retention.

Design and features

• Gap-free closed-seal geometry without gaps or undercuts.
• Flexible sealing lip providing the required seal via an integrated preload element.
• Bayonet mount for quick installation and significantly reduced replacement time compared with screw-mounted pistons.
• Housing and cover in stainless steel for hygienic integrity and durability.
• Can be retrofitted to replace existing steel piston + sliding ring solutions.

Materials and cleaning

• Material options include various FDA-compliant PTFE compounds and UHMW-PE.
• Cleaning capability depends on material: CIP (Cleaning in Place) possible up to approx. 80°C for some materials.
• SIP (Steam sterilisation in Place) up to 140°C is possible with appropriate PTFE compounds.
• UHMW-PE versions allow CIP but not SIP; UHMW-PE offers higher abrasion resistance than many PTFE compounds.

Customization

• Offered in standard geometries and customised versions.
• Customisation options: geometry, dimensions, material selection, preload element and sealing lip attachment.

Applications
Intended for hygienic filling of liquid and paste-like media in the food and pharmaceutical industries, and for retrofit of existing dosing systems requiring improved hygienic performance.

characteristics / technical specifications

• Type: Closed-seal dosing piston (gap-free).
• Sealing: Flexible sealing lip with integrated preload element.
• Mounting: Bayonet mount for rapid installation and replacement.
• Housing/Cover: Stainless steel.
• Materials: FDA-compliant PTFE compounds and UHMW-PE.
• CIP compatibility: Up to approx. 80°C depending on material.
• SIP compatibility: Up to 140°C possible with appropriate PTFE compound.
• Abrasion resistance: UHMW-PE versions are more abrasion-resistant than PTFE-compound versions.
• Use case: Replacement/adaptation for existing steel piston + sliding ring solutions.