EM Design Gasket Seal
CPR Hole Patterns – 187, 284, 340, 650 & 770
Patent No. 5,765,835

Unit Specifications

This gasket seal is a nominal 3 mm thick and is composed of three distinct parts.  Together, these three parts make up the gasket, which is used to connect two waveguide flanges together.

  • Outer aluminum section; contains the flange hole pattern and acts as the outer restraint for the o-ring.
  • The o-ring; provides the pressure or desired vacuum seal.  And,
  • A solid copper inner section; contained within the o-ring perimeter, it serves to provide inside restraint.  The copper section provides a solid contact for waveguide currents and heat transfer.


The EMD gasket seal is a unique, patented, mechanism used to connect and seal high power waveguide flat flanges.  It consists of three separate components; the inner copper component, the outside aluminum piece and the o-ring.  The inner copper component is slightly thicker than the outside aluminum piece.  It ensures that the seal, when clamped between two flat flanges, will provide contacting pressure on the copper component.  The copper component is contained entirely with the o-ring seal and is protected from weather or galvanic effects by the waveguide gas or vacuum.

Especially important to note, is the EMD Seal is designed so that, if necessary, any one of the three components can be replaced.  This provides you with the option of replacing just needed parts, not the entire seal.  Saving you time and money.

CPR 187, 284, 340, 650 and 770 flange sizes are available.  As well as the Varian 8-hole configuration for mating Varian WR284 flat flanges.

Waveguide Gasket Seal, CPR 284.PDF