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Compressor Case

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(kum-PRES-er kays)

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A Compressor Case is a type of watch case that increases its water resistance as external pressure increases, using the pressure to compress the case back against the gasket, enhancing the seal.

What does

Compressor Case

mean?

A compressor case is a type of watch case design patented by Ervin Piquerez SA (EPSA) in the 1950s, primarily used in diving watches. This innovative design enhances water resistance by utilizing external water pressure to compress the case back against the watch case, thereby increasing the seal's effectiveness as the watch descends deeper underwater. Unlike traditional waterproof cases, which rely on constant pressure from screw-down backs, the compressor case only applies pressure to the seals when necessary, reducing wear and tear. This design was further developed into the Super Compressor case, which included features like dual crowns for setting time and adjusting an internal rotating bezel, making it suitable for professional diving. The compressor case technology was a significant advancement in watchmaking, allowing for greater water resistance without constant stress on the seals, and it remains a celebrated innovation among watch enthusiasts and collectors.
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Frequently Asked Questions

What makes a compressor case different from regular dive cases?

A compressor case uses external water pressure to push the case back against the gasket, increasing the seal tightness as depth increases. Unlike traditional dive cases that rely on constant screw-down pressure, compressor cases become more water-resistant as you go deeper—the pressure that threatens the watch also protects it.

What is a Super Compressor case?

The Super Compressor case, developed by EPSA in the 1950s, enhanced the original compressor design by adding dual crowns: one for setting time and one for adjusting an internal rotating bezel, all without opening the case. Notable examples include vintage Blancpain Fifty Fathoms and Longines ultra-chron dive watches.

Are compressor cases still made today?

Modern dive watches use screw-down crowns with multiple gaskets rather than compressor mechanisms, as advances in gasket materials and case engineering have surpassed the original compressor concept. However, several brands including Jaeger-LeCoultre have revived the dual-crown Super Compressor aesthetic in modern reissues, though without the original pressure-compression mechanism.

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