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Packing tackles aggressive slurries
jan03 sealing technology.qxd
22/01/2003
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NEWS temperatures up to 200°C; that provided a wide-ranging stroke capability; and could respond quickly and accurately to pressure changes, despite the demanding operating temperatures. The ModEvo tension control brake was developed by Wichita in direct response to market requirements for a system that could provide the appropriate braking force, but also had the sensitivity to cope with paper or film web changes of varying thickness that are typically found in print and converting industries. Wichita says that more conventional braking systems, which use pistons to provide the resisting force, were less able to offer the required sensitivity, so it decided to incorporate rolling diaphragms into the actuator option on the modular ModEvo. The maker of clutches and brakes quickly dismissed the conventional ‘top hat’ rolling diaphragm design because the size necessary to meet performance requirements was too large for the desired application envelope. Ceetak says that it was able to meet all the design parameters set by Wichita, including size, by incorporating an internal bead which optimizes space for increased stroke capacity. For more information, contact: Ceetak, 1 Napier Road, Bedford MK41 0QR, UK. Tel: +44 1234 327901, Fax: +44 1234 327909.
The gaskets can be custom cut from expanded silicone sponge sheet – offering the special benefits of this type of material – in a density of 0.3 g/cm3 to 0.5 g/cm3 (16 lb/ft3 to 33 lb/ft3), and that is resistant to temperatures of –50°C to +200°C. Vulcanized, joined gaskets and seals are also available from both solid and sponge extruded profiles. Simple O-rings and more complicated profiles with mitred corners to tight tolerances can also be supplied. Acrylic-based double-sided tape or silicone pressure-sensitive adhesive backing are available as an option on all cut gaskets. For more information, contact: Samco Silicone Products, Secton Court, Attleborough Fields Industrial Estate, Nuneaton, Warwickshire CV11 6AT, UK. Tel: +44 2476 641270, Fax: +44 2476 344992.
Packing tackles aggressive slurries James Walker of Old Woking, UK, has launched its new Aluflon compression packing
Silicone gaskets are produced to order In the UK, Samco Silicone Products claims that its improved in-house gasket-cutting service can now produce prototype or large batches of punched silicone gaskets (specified by customer drawings) in a wider choice of materials and cut forms. The company says that gaskets can be produced using solid silicone sheet (40–70 Å) in a range of colours. They are also made from silicone that is approved for use with foodstuffs and that is suitable for continuous use over a temperature range of –60°C to +220°C.
Sealing Technology January 2003
worldwide, following outstanding success in Australia where it was used with highly aggressive chemical slurries. The product was originally developed as shaft gland packing for pumps used by the Australian alumina industry. Over the past 12 months, its resistance to highly caustic slurries and strong acids has significantly reduced plant downtime and extended maintenancefree periods for process operators, claims the company. James Walker says that it produces Aluflon as a soft and conformable, low-friction packing with a wide chemical compatibility for media of pH 0–14. It is cross-plaited from ‘yarn’ that has a reinforced glass insert with a spun cover of polyolefin fibre. All components are impregnated and coated with polytetrafluoroethylene micro-particles and an inert petroleum lubricant to minimize break-out friction and shaft wear. Aluflon operates over a temperature range of –50°C to +130°C. Maximum operating pressures are 10 MP (100 bar) for valves; 5 MP (50 bar) for reciprocating pumps and 2 MP (20 bar) for centrifugal pumps. Recommended shaftspeed limits are 12 m/s on rotary duties and 2 m/s for reciprocating operations. The packing is manufactured in the UK and is supplied exstock in all popular square sections with side lengths ranging from 3 mm to 25 mm, and it is boxed in 8 m lengths. Preformed rings and sets are also available from the company. For more information, contact: James Walker & Co Ltd, Hoe Bridge, Old Woking, Surrey GU22 8JL, UK. Tel: +44 1483 757575, Fax: +44 1483 746105.
Rings of James Walker’s Aluflon compression packing are carefully cut to size on a rod which has the same diameter as the pump shaft or valve stem that is being sealed. The packing material is now supplied worldwide by the company following its successful use, with highly aggressive slurries, in the Australian alumina industry.
O-ring compression controlled A metal-to-metal ferrule design, which uses a metal stop to control O-ring compression, is allowing BBS-Systems’ ‘Quick Connect’ sterile fittings to virtually eliminate the back-pressure
In Brief Website covers adhesives and sealants An on-line service that is dedicated entirely to raw materials that are used in adhesives and sealants is now accessible on the Internet at www.specialchem4adhesives. com. Developed and set up by SpecialChem, it gives formulators, original equipment manufacturers and industrial designers access to specialized technical information. It comprises a complete range of services including a comprehensive technical library; a database containing over 6000 additives, tackifiers and resins; and what is described as a rapid and efficient technical assistance service. Users can log on to the site to gain an insight into recent technical developments, formulate products and materials more easily, and even solve technical problems on-line, says the company. Duke Energy honoured by US EPA US-based Duke Energy Gas Transmission (DEGT) has received the ‘2002 Transmission Partner of the Year’ award from the US Environmental Protection Agency (EPA). The award was given in recognition of DEGT’s efforts to reduce methane released into the atmosphere during the course of standard natural gas transportation operations. Methane can escape during pipeline venting and repair or, to a lesser extent, from valves and seals at compressor stations. DEGT uses four methods to reduce emissions — hot taps for new connections; sleeve repairs; pipeline pull downs; and through an emergency shutdown. The company entered the EPA’s ‘Natural Gas STAR’ programme during 2000 and received the award after one year of eligibility. Free literature details construction sealants Free literature that has been published by Sika’s Industrial Business Unit covers the company’s metal construction sealants and adhesives product line. It includes descriptive information on the complete line of SikaLastomer butyl tapes, SikaLastomer hot melt sealants, SikaLastomer nonskinning butyl caulk, and Sikaflex one-part polyurethane sealants.
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22/01/2003
15:19
Page 3
NEWS temperatures up to 200°C; that provided a wide-ranging stroke capability; and could respond quickly and accurately to pressure changes, despite the demanding operating temperatures. The ModEvo tension control brake was developed by Wichita in direct response to market requirements for a system that could provide the appropriate braking force, but also had the sensitivity to cope with paper or film web changes of varying thickness that are typically found in print and converting industries. Wichita says that more conventional braking systems, which use pistons to provide the resisting force, were less able to offer the required sensitivity, so it decided to incorporate rolling diaphragms into the actuator option on the modular ModEvo. The maker of clutches and brakes quickly dismissed the conventional ‘top hat’ rolling diaphragm design because the size necessary to meet performance requirements was too large for the desired application envelope. Ceetak says that it was able to meet all the design parameters set by Wichita, including size, by incorporating an internal bead which optimizes space for increased stroke capacity. For more information, contact: Ceetak, 1 Napier Road, Bedford MK41 0QR, UK. Tel: +44 1234 327901, Fax: +44 1234 327909.
The gaskets can be custom cut from expanded silicone sponge sheet – offering the special benefits of this type of material – in a density of 0.3 g/cm3 to 0.5 g/cm3 (16 lb/ft3 to 33 lb/ft3), and that is resistant to temperatures of –50°C to +200°C. Vulcanized, joined gaskets and seals are also available from both solid and sponge extruded profiles. Simple O-rings and more complicated profiles with mitred corners to tight tolerances can also be supplied. Acrylic-based double-sided tape or silicone pressure-sensitive adhesive backing are available as an option on all cut gaskets. For more information, contact: Samco Silicone Products, Secton Court, Attleborough Fields Industrial Estate, Nuneaton, Warwickshire CV11 6AT, UK. Tel: +44 2476 641270, Fax: +44 2476 344992.
Packing tackles aggressive slurries James Walker of Old Woking, UK, has launched its new Aluflon compression packing
Silicone gaskets are produced to order In the UK, Samco Silicone Products claims that its improved in-house gasket-cutting service can now produce prototype or large batches of punched silicone gaskets (specified by customer drawings) in a wider choice of materials and cut forms. The company says that gaskets can be produced using solid silicone sheet (40–70 Å) in a range of colours. They are also made from silicone that is approved for use with foodstuffs and that is suitable for continuous use over a temperature range of –60°C to +220°C.
Sealing Technology January 2003
worldwide, following outstanding success in Australia where it was used with highly aggressive chemical slurries. The product was originally developed as shaft gland packing for pumps used by the Australian alumina industry. Over the past 12 months, its resistance to highly caustic slurries and strong acids has significantly reduced plant downtime and extended maintenancefree periods for process operators, claims the company. James Walker says that it produces Aluflon as a soft and conformable, low-friction packing with a wide chemical compatibility for media of pH 0–14. It is cross-plaited from ‘yarn’ that has a reinforced glass insert with a spun cover of polyolefin fibre. All components are impregnated and coated with polytetrafluoroethylene micro-particles and an inert petroleum lubricant to minimize break-out friction and shaft wear. Aluflon operates over a temperature range of –50°C to +130°C. Maximum operating pressures are 10 MP (100 bar) for valves; 5 MP (50 bar) for reciprocating pumps and 2 MP (20 bar) for centrifugal pumps. Recommended shaftspeed limits are 12 m/s on rotary duties and 2 m/s for reciprocating operations. The packing is manufactured in the UK and is supplied exstock in all popular square sections with side lengths ranging from 3 mm to 25 mm, and it is boxed in 8 m lengths. Preformed rings and sets are also available from the company. For more information, contact: James Walker & Co Ltd, Hoe Bridge, Old Woking, Surrey GU22 8JL, UK. Tel: +44 1483 757575, Fax: +44 1483 746105.
Rings of James Walker’s Aluflon compression packing are carefully cut to size on a rod which has the same diameter as the pump shaft or valve stem that is being sealed. The packing material is now supplied worldwide by the company following its successful use, with highly aggressive slurries, in the Australian alumina industry.
O-ring compression controlled A metal-to-metal ferrule design, which uses a metal stop to control O-ring compression, is allowing BBS-Systems’ ‘Quick Connect’ sterile fittings to virtually eliminate the back-pressure
In Brief Website covers adhesives and sealants An on-line service that is dedicated entirely to raw materials that are used in adhesives and sealants is now accessible on the Internet at www.specialchem4adhesives. com. Developed and set up by SpecialChem, it gives formulators, original equipment manufacturers and industrial designers access to specialized technical information. It comprises a complete range of services including a comprehensive technical library; a database containing over 6000 additives, tackifiers and resins; and what is described as a rapid and efficient technical assistance service. Users can log on to the site to gain an insight into recent technical developments, formulate products and materials more easily, and even solve technical problems on-line, says the company. Duke Energy honoured by US EPA US-based Duke Energy Gas Transmission (DEGT) has received the ‘2002 Transmission Partner of the Year’ award from the US Environmental Protection Agency (EPA). The award was given in recognition of DEGT’s efforts to reduce methane released into the atmosphere during the course of standard natural gas transportation operations. Methane can escape during pipeline venting and repair or, to a lesser extent, from valves and seals at compressor stations. DEGT uses four methods to reduce emissions — hot taps for new connections; sleeve repairs; pipeline pull downs; and through an emergency shutdown. The company entered the EPA’s ‘Natural Gas STAR’ programme during 2000 and received the award after one year of eligibility. Free literature details construction sealants Free literature that has been published by Sika’s Industrial Business Unit covers the company’s metal construction sealants and adhesives product line. It includes descriptive information on the complete line of SikaLastomer butyl tapes, SikaLastomer hot melt sealants, SikaLastomer nonskinning butyl caulk, and Sikaflex one-part polyurethane sealants.
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