PATENTS

12Sealing Technology March 2013

PATENTSFluid sealing for flexible pipes

Applicant: Wellstream International Ltd, UKThis invention relates to a fluid seal and associated assembly, a method for providing the seal and terminating a flexible pipe body in an end fitting. In particular, but not exclusively, it covers a seal for use in the end fittings of flexible pipes. It aims to provide an improved sealing ring element and enhanced methods of sealing layers of the pipe body. According to the inventors, one embodi-ment provides details of a ring element that has enhanced sealing properties – particularly when it is used in applications that involve high pressures.Patent number: WO/2012/146905 Inventors: G. Karabelas and R.A. ClementsPublication date: 1 November 2012

Method for sealing the ends of an air spring

Applicant: Wabtec Holding Corp, USAAn arrangement has been developed for attaching and sealing the ends of an air spring that does not require conventional fasteners, mechanical fastening operations or bonding and/or adhesives. Specifically, the arrangement involves interlocking each end of a flexible elastomeric sleeve with the respective end member, and uses air pressure to seal the junc-ture of the flexible elastomeric sleeve and the end member at the interlocking mechanism.Patent number: WO/2012/148892 Inventor: M.E. RingPublication date: 1 November 2012

Wear-resistant coating

Applicant: Waters Technologies Corp, USADescribed are embodiments of a pump that can be used, for example, in liquid chromatography applications. The pump includes a seal wash housing, pump head and seal assembly. A wear-resistant coating that is applied to a sealing surface or gland of the pump head, or seal wash housing, improves the hardness and chemical compatibility of the sealing surface. Oxidation of the sealing surface is reduced so that it is less abrasive to the seal assembly, and the service life of the assembly is extended.Patent number: WO/2012/148726 Inventors: J.A Shreve, N.B. Almeida, J. Angelosanto and J.A. LuongoPublication date: 1 November 2012

‘‘Tolerance-compatible’’ flat seal

Applicant: Federal-Mogul Sealing Systems GmbH, GermanyThis patent provides details of a flat seal that is described has having a ‘‘tolerance-compatible fixing’’. It comprises at least one sheet-metal layer (2), which has at least one through-opening (8). Also described is at least one substantially T-shaped fixing cut-out (4) for a centring element (10). The width (b), within the trunk of the T-shape, is smaller than the corresponding outer width of the centring element, and the length (h) of the fixing cut-out – in the direction of the trunk of the T-shape – is greater than the cor-responding outer width of the centring ele-ment. In each case, one cut-out (6) is laterally opposed to the trunk of the T-shape. The fix-ing cut-out (4), with the arms of the T-shape, faces the edge of the through-opening (8). Patent number: WO/2012/146400Inventors: B. Gadomski and E. SzelePublication date: 1 November 2012

Seal for switch valves

Applicant: Schaeffler Technologies Ag & Co Kg, GermanyThis invention relates to a switch valve for a hydraulic unit. In particular, the patent refers to a quick-acting valve for a hydraulic unit of a hydraulically variable valve gear that is part of a reciprocating internal combustion engine. It consists of a valve body, which is guided in an axially moveable manner in a housing part, and is sealed with respect to this housing part. The seal design described is a flat seal element, which encloses the valve body and is connected to an axial surface of the housing part.

Patent number: WO/2012/150048 Inventor: C.P. ItoafaPublication date: 8 November 2012

Hydrodynamic seal with increased flexibility

Applicant: Federal-Mogul Corp, USAThis invention relates generally to hydrody-namic seals, but in particular to the formation of a sealing element that has enhanced flex-ibility. The hydrodynamic shaft seal assembly includes a polytetrafluoroethylene (PTFE) member that has outer and inner sections. The outer section is affixed to an annular carrier. The inner section is free and includes at least one hydrodynamic groove that is in direct running contact with a rotating shaft, or wear sleeve. A mid-portion of the seal member, formed between the inner and outer sections, is thinned and contains one or more annular undulations to improve flexibility of the inner section, relative to the outer section. The seal assembly also may include one or more exclud-er features. A rubber casing is moulded around portions of the carrier. Preferably, one or more annular undulations are formed in a coining operation during the rubber-moulding process.Patent number: WO/2012/151189 Inventors: F.R. Hatch and D.M. TothPublication date: 8 November 2012

Valve stem seal arrangement

Applicant: Aker Subsea As, NorwayThis invention relates to valves that close or open for a fluid under high pressure. For example, they can be integrated into a sub-sea ‘‘Christmas tree’’ used in the production of oil and gas. More specifically, this invention relates to the seals found in sub-sea valves that are used for control purposes in oil and gas production. The seals described also may be used in other similar valves required by sub-sea or top-side applications, say the inventors. The valve com-prises a valve element, a valve-element pressure housing, an actuator, a stem and a bonnet. Via the stem the actuator is arranged to close or open a fluid passageway through the valve element. The bonnet encloses the stem and is connected to the valve-element pressure housing and seals are arranged between the stem and the bonnet for sealing against the pressure of the valve element housing. The valve is distinctive in that it comprises at least one seal for sealing between the stem and bonnet – the seal having an identical inner sealing diameter, against the stem, and outer sealing diameter, against a single body or element of the bonnet. This approach reduces the number of seal geometries required and simplifies testing and maintenance.

Patent WO/2012/146400 provides details of what is referred to as a ‘‘tolerance-compatible’’ flat seal.