Series SPM and series SPZ pneumatic expansion couplings

Innovative Secure Clamping for Thin-Walled Cores

The Pneumatic Expansion Coupling Series SPM/SPZ from Vorwald represents a modern evolution in expansion coupling technology, specifically designed to provide secure, gentle, and efficient clamping for thin-walled cores and narrow webs. These couplings leverage a unique design principle that sets them apart from traditional inflatable ring couplings, making them ideal for applications where core integrity and rapid changeover are essential.

Unlike conventional expansion couplings that rely on inflatable rings clamping directly onto the core — a method often associated with bladder wear and potential damage — the Series SPM/SPZ employs continuous expansion leafs crafted from lightweight aluminum. These leafs expand lengthwise when pressurized via an internally seated, replaceable bladder, which is protected from direct wear thanks to this innovative configuration.

This design offers several critical advantages:

• Durability and reliability: The bladder is shielded from direct abrasion, significantly extending its operational lifespan compared to conventional couplings.
• Safety and performance: An integrated expansion stop limits the leaf expansion, allowing clamping pressures up to 6 bar without risking bladder rupture, even when no winding core is present.
• Strong grip: The broad contact surface of the aluminum leafs on the bladder translates to a firm, even clamping force. This ensures the core remains securely fixed, even under conditions of rapid starts and stops.

Flexible and Customizable for Your Needs

The Series SPM/SPZ comes in several standard sizes — including 70, 76, 150, and 152 mm take-up bores — with various external diameter options to suit diverse core dimensions. A version with either a flange or a bearing journal (Series SPZ) expands its versatility further.

Key options include:

• Surface protection coatings
• Food-grade versions suitable for the foodstuffs industry
• Customizable core stops with free positioning
• Flange configurations
• Special dimensions available upon request

Why Choose the Series SPM/SPZ?

These expansion couplings excel in applications requiring a delicate touch — especially where thin-walled cores are prone to deformation and damage with other expansion systems. Their lightweight design and ease of handling facilitate quick and simple core diameter changes, minimizing downtime and enhancing operational efficiency.

Advantages at a glance:

• Rapid core diameter conversions
• Lightweight coupling design for easier handling
• Reliable clamping with minimal core deformation
• Ideal for narrow webs and delicate cores
• Customizable take-up bore dimensions
• Suited primarily for light-duty applications