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Rotatable pipe fitting for a sprinkler head
PATENTS filter elements is described by this patent. The axial seal is supported by, and attached to, the filter media pack by a media pack seal member. Alternatively, the seal member may be carried by a frame, which is attached to the filter media pack by the media pack seal member. Numerous different systems are illustrated. A typical example uses a soft elastomer axial seal and a harder material for the media pack seal. Patent number: WO/2010/117606 Inventors: K. Swanson, C. Banzhaf and S.J. Merritt Publication date: 14 October 2010
Rotatable pipe fitting for a sprinkler head Applicant/Inventor: W. Spears, USA A pipe fitting (10) that is designed to be installed on a sprinkler head (12) is described. The fitting is sealed by screwing it down onto a seal (16) in a recess. The seal has an oval section, with the major diameter oriented longitudinally to the thread axis. This enables the head to be rotated within the downstream end of the body (14) through 360º while remaining liquid tight for pressures in excess of 20 bar (300 psig). Patent number: WO/2010/117988 Publication date: 14 October 2010
Rotary seal with truncated wave form Applicant: Kalsi Engineering Inc, USA A development of the well established Kalsi seal, which uses a wavy circumferential profile, is described. This invention relates to a feature that improves seal lubrication in adverse conditions, such as high operating temperatures, skew-resisting confinement, high differential pressure, high initial com-
A revised version of the Kalsi wave-seal – designed to improve lubrication under adverse conditions (patent WO/2010/118253).
pression, adverse tolerance accumulation, circumferential compression, high modulus seal materials, dynamic run-out, reversing differential pressure, thin viscosity lubricants, third-body seal surface wear, and/or material swell. In some cases, certain designs fall short when exposed to severe operating conditions. Smaller seal cross-sections are desirable because the shaft and housing wall thickness can be maximised. Miniaturisation affects seal lubrication. For a given dimensional compression, interfacial contact pressure increases as the seal cross-section is miniaturised. With radial seals, circumferential compression increases as the diameter is miniaturised, increasing footprint spread and contact pressure. The incorporation of a bidirectional ‘‘diverter’’ on the dynamic lip moves additional lubricant into critical areas of the
An oval-section seal enables the sprinkler head to be adjusted through 360º. Patent WO/2010/117988 has further details.
March 2011
sealing interface. This diverter is preferably implemented in a way that also helps to minimise seal volume for improved compatibility with skew-resisting confinement. The diverter geometry also preferably intersects both the traditional dynamic sealing surface and the traditional hydrodynamic inlet, and may also intersect the lubricant-side flank of the dynamic lip. The diverter can be incorporated by ‘‘faceting’’ or scalloping the wave to give it a truncated appearance. Elastomeric materials that may be combined with various plastic materials – such as those based on reinforced polytetrafluoroethylene (PTFE) plastics – may be used. Seals may have a monolithic integral, one-piece construction, or may also incorporate different materials bonded, inter-fitted and co-vulcanised. Patent number: WO/2010/118253 Inventor: J.E. Schroeder Publication date: 14 October 2010
Flange seal Applicant/Inventor: C. Oldnall, Australia This flange sealing assembly uses a pair of gaskets separated by a spacer. The spacer is an annular hydraulic cylinder that is used to load the gasket. A single-acting version is also illustrated for pipe end flanges. After flange loading the spacer may be mechanically locked in position by a locking ring to maintain the flange load. Alternatively, the hydraulic pressure is locked off in the spacer by a non-return valve to maintain the load. This device is said to be particularly useful for joints that have to be taken apart regularly as it is also effectively a spool piece. Illustrations show it being used with spiralwound gaskets and metal ring joints. Patent number: WO/2010/118464 Publication date: 21 October 2010 Technical Editor’s comment: This is good news for gasket suppliers, as they are able to sell two gaskets. The sealing of the hydraulic piston is
A hydraulic loading spool for gasket assemblies. Patent WO/2010/118464 has further details.
Sealing Technology
13
Rotatable pipe fitting for a sprinkler head Applicant/Inventor: W. Spears, USA A pipe fitting (10) that is designed to be installed on a sprinkler head (12) is described. The fitting is sealed by screwing it down onto a seal (16) in a recess. The seal has an oval section, with the major diameter oriented longitudinally to the thread axis. This enables the head to be rotated within the downstream end of the body (14) through 360º while remaining liquid tight for pressures in excess of 20 bar (300 psig). Patent number: WO/2010/117988 Publication date: 14 October 2010
Rotary seal with truncated wave form Applicant: Kalsi Engineering Inc, USA A development of the well established Kalsi seal, which uses a wavy circumferential profile, is described. This invention relates to a feature that improves seal lubrication in adverse conditions, such as high operating temperatures, skew-resisting confinement, high differential pressure, high initial com-
A revised version of the Kalsi wave-seal – designed to improve lubrication under adverse conditions (patent WO/2010/118253).
pression, adverse tolerance accumulation, circumferential compression, high modulus seal materials, dynamic run-out, reversing differential pressure, thin viscosity lubricants, third-body seal surface wear, and/or material swell. In some cases, certain designs fall short when exposed to severe operating conditions. Smaller seal cross-sections are desirable because the shaft and housing wall thickness can be maximised. Miniaturisation affects seal lubrication. For a given dimensional compression, interfacial contact pressure increases as the seal cross-section is miniaturised. With radial seals, circumferential compression increases as the diameter is miniaturised, increasing footprint spread and contact pressure. The incorporation of a bidirectional ‘‘diverter’’ on the dynamic lip moves additional lubricant into critical areas of the
An oval-section seal enables the sprinkler head to be adjusted through 360º. Patent WO/2010/117988 has further details.
March 2011
sealing interface. This diverter is preferably implemented in a way that also helps to minimise seal volume for improved compatibility with skew-resisting confinement. The diverter geometry also preferably intersects both the traditional dynamic sealing surface and the traditional hydrodynamic inlet, and may also intersect the lubricant-side flank of the dynamic lip. The diverter can be incorporated by ‘‘faceting’’ or scalloping the wave to give it a truncated appearance. Elastomeric materials that may be combined with various plastic materials – such as those based on reinforced polytetrafluoroethylene (PTFE) plastics – may be used. Seals may have a monolithic integral, one-piece construction, or may also incorporate different materials bonded, inter-fitted and co-vulcanised. Patent number: WO/2010/118253 Inventor: J.E. Schroeder Publication date: 14 October 2010
Flange seal Applicant/Inventor: C. Oldnall, Australia This flange sealing assembly uses a pair of gaskets separated by a spacer. The spacer is an annular hydraulic cylinder that is used to load the gasket. A single-acting version is also illustrated for pipe end flanges. After flange loading the spacer may be mechanically locked in position by a locking ring to maintain the flange load. Alternatively, the hydraulic pressure is locked off in the spacer by a non-return valve to maintain the load. This device is said to be particularly useful for joints that have to be taken apart regularly as it is also effectively a spool piece. Illustrations show it being used with spiralwound gaskets and metal ring joints. Patent number: WO/2010/118464 Publication date: 21 October 2010 Technical Editor’s comment: This is good news for gasket suppliers, as they are able to sell two gaskets. The sealing of the hydraulic piston is
A hydraulic loading spool for gasket assemblies. Patent WO/2010/118464 has further details.
Sealing Technology
13