PATENTS

12Sealing Technology March 2006

PatentsIsolation damper with air- tight seal

Applicant: Daniel EnvironmentalCo, USA

This patent describes an isolationdamper for use in air deliverytrunking. The damper – which maybe elliptical – is provided with a sealto provide an air-tight cutoff. It can

be used to shut off airflow to pre-vent circulation of hazardous conta-minants in clean environments.Patent number: WO 2005/108556Inventors: T.E. Malki and

D.R. OlsonPublication date: 17 November 2005

Low-pressure, gas-tight stem seal for back-up use

Applicant: Baker Hughes Inc, USAThis patent describes a low-pres-sure back-up seal to the main stemseal of a gate valve, to provide agas-tight seal during normal oper-ations when the valve is in itsclosed position. The back-up sealis frequently expected to hold backat least 15 bar gas pressure in thevalve body. The seal is intended toovercome problems associatedwith metal-to-metal seals and alsoO-ring designs that could be dis-lodged by fluid flow when thevalve is open. The back-up stem

seal retains pressure in the bodywhen the valve is in the closedposition. The back-up seal is sec-ondary to the main stem sealassembly (20) in the bonnet (12).It features metal-to-metal contactbetween surfaces (22, 24) that areeither radially oriented or sloping.A groove (26) contains a seal ring(32) in one or both of the opposedmetal-to-metal surfaces.Patent number: WO 2005/106302Inventors: G.R. Thompson and

A.T. JacksonPublication date: 10 November 2005

Pipe joint with a defined sealing effect

Applicant: Vulkan Lokring-Rohrverbindungen GmbH,Germany

A pipe joint is described in thispatent that is designed to providelow assembly forces and permitassembly without twisting ordamaging the seal. The connec-tion piece (1) is deformed in adefined manner when the ring (3)is slid into position. The sealing

element (4) is pressed between thechamber (5) wall and the pipe (2).The connection piece is crimpedto the pipe when the joint isclosed, resulting in the creation ofa mechanically stable connectionthat is additionally used as anemergency seal.Patent number: WO 2005/103549Inventor: D. SchwalmPublication date: 3 November 2005

Improved joint for electrochemical devices

Applicant: Battelle MemorialInstitute, USA

This patent describes a joint foruse in electrochemical devices,such as solid oxide fuel cells(SOFCs), oxygen separators andhydrogen separators that willmaintain a hermetic seal at oper-ating temperatures above 600°C.The joint is expected to surviverepeated thermal cycling at excessof 600°C in a hostile operatingenvironment, where one side ofthe joint is continuously exposedto an oxidizing atmosphere andthe other side to a wet reducing

gas. The joint is formed by ametal component, a ceramic partand a flexible gasket. The flexiblegasket is metal, but is thinnerand more flexible than the metalcell component. As the joint isheated and cooled, the flexiblegasket is configured to flex inresponse to the thermal strains ofthe cell components. The seal isexpected to operate for morethan 10 000 hours.Patent number: WO 2005/106999Inventors: K.S. Weil and J.S. HardyPublication date:

10 November 2005

Patent WO 2005/103549 describes a pipe joint that uses a taper sleeveto provide low assembly force that both compresses the seal in positionand crimps the pipe. The valve stem back-up seal for oil-field gate valves reported in

WO 2005/106302 is designed to provide a low-pressure, leak-tight seal.

Seal for sealing opening in plastic extrusion machine

Applicant: Krauss-MaffeiKunststofftechnik GmbH,Germany

This patent describes a seal for anopening, in particular for a cool-ing device of a plastic extrusionmachine. The sealing body isdesigned in such a way that it can

be crossed by an object and ismade at least in part of an elasticmaterial.Patent number:

WO 2005/108830Inventors: H. Stieglitz et al.Publication date:

17 November 2005

Mechanical seal with a central component

Applicant:AES Engineering Ltd, UK

This seal is described in more detailin the feature article on page 11.

Patent number: WO 2005/121615Inventor: E. Taheri OskoueiPublication date:

22 December 2005