Maintenance and costs focus for seal technology

Modern seals have to give long-term, assured sealing at high temperatures and pressures, and be able to work with a wide range of fluids. Eugene McCarthy reports.
 
Replacing other more costly yet less efficient mechanical seals, and converting packing on pumps and rotating shaft equipment, the John Crane 4610 cartridge seal reduces maintenance and running costs, product leakage and equipment downtime. Particularly easy and quick to install, without the need for seal setting, equipment modification or additional components, the company says it brings a new level of affordability with assured dependability to fluid sealing in general industrial applications, particularly the water and wastewater sectors.
 
This single cartridge seal meets key industry pump standards and can be used in rotating shaft equipment where ANSI/DIN/API design seals will not fit, including water-based and close-coupled or vertical water pumps. Seal size range is currently from 24 to 70mm with a performance capability of 3600 rpm at pressures up to11 bar and temperatures up to 130°C.
 
A computer-optimised hydraulically balanced running face design incorporates premium grade carbon and silicon carbide as standard for optimal performance, with a robust pin drive for positive torque transmission. Eliminating drive screw damage to pump shaft or sleeve, the seal's robust indirect through-sleeve drive mechanism ensures positive torque transmission. A non-clogging crest-to-crest wave spring is used instead of fragile, easily clogged helical coil springs to provide constant face loading, improved corrosion resistance and easy assembly.
 
The novel, precise investment cast gland plate design has a 1/4in NPT flush port giving better cooling/venting and a large flush connection drilling that ensures optimum flow in applications requiring product re-circulation or clean flushing over the seal faces while allowing seal chamber venting for horizontal or vertical applications. Four-bolt fixing provides accurate seal setting. A novel centralising ring eliminates the need for setting clips while still accurately setting the seal both axially and radially, and preventing component damage from over-compression during seal installation.
 
Valve stem seals must also offer long life and reliable sealing capabilities. Traditional solutions result in high torque requirements on the valve stem which makes actuation more costly and in service use more difficult.
 
To counter this, Fluorocarbon has introduced new Stem Seals to solve high torque problems on gate and choke valves.
 
The Stem Seal criteria was to design a seal that could give long term assured sealing at high pressures over a wide temperature range, be suitable in any media, significantly reduce valve torque and give a greater than20 year life.
 
The careful selection of materials and consideration to design has allowed Fluorocarbon to meet these criteria at a price which remains competitive compared to traditional solutions whilst increasing reliability.
 
The new Fluorocarbon Stem Seal is the preferred choice for a number of leading international valve manufacturers which differentiates their product over manufacturers still using traditional sealing methods. Valves using the Stem Seal can meet the following criteria: temperatures from -100°C to 250°C (cryogenic is available too); pressure – 15,000 psi cyclic, 22,500 psi static; and torque reductions from over 300 ft lbs to less than 100ft lbs.
 
Fluorocarbon says that at present the new seals are mainly being used in gate, choke and ball valves, although it can adapt designs to suit most applications and sizes. [Page Break]
 
Thermal stability
 
New from Klinger, the KLINGERSIL C-4430 Plus is a universal sealing material suitable for a large number of fluids. As it is compatible with water, steam, hydrocarbons, oil, light acids and light bases, the company says it is ideal for a wide range of applications.
 
The most important feature of the new KLINGERSIL C-4430 plus is its high temperature heat resistant NBR matrix, which is used as binder. This new technology has been used for the first time with KLINGER Quantum. It provides scope for improvements of several key characteristics, which have all been verified in numerous standardised tests.
 
One of these is for thermal stability. Here KLINGERSIL C-4430 Plus benefits from the new cross-link technology and now features considerably higher stability. This results in the greatest heat resistance ever. According to Klinger, the maximum temperature is 50°C higher than those of other materials, and allows higher process temperatures.
 
Another test was on product life time. Usually, elastomers used for sealing materials deteriorate over time. Periodical replacement is absolutely essential to sustain safe operation. But the extended lifetime of KLINGERSIL C-4430 Plus, on the other hand, makes longer service intervals and reduced service costs possible.
 
The seal has almost met a raft of safety and temperature tightness guidelines. “Thanks to the high temperature heat resistance, KLINGERSIL C-4430 Plus is suitable for even very demanding situations. Due to the compatibility with numerous fluids and the large number of approvals it also covers a wide range of applications,” notes the company.
 
Among a host of innovative products available from Garlock Sealing Technologies (GST) are ultra high temperature gasket materials such as THERMa-PUR. These new materials were developed from the ground up, using new materials and with numerous patents applied for. For over three years, the company worked closely with many customers, carrying out over 2000 beta tests in many different processing industries and locations.  
 
In terms of THERMa-PUR, it is a blended proprietary material that is designed for temperatures up to 1000°C (Fig. 1). Markets for this include process drying equipment, mineral and fertiliser processing, oil and gas production and co-generation systems.
 
In January, specialised sealing solutions company FDS Group was renamed The Flexitallic Group. The move comes in response to the expanding global presence, recognition and value of Flexitallic, one of the Group's premier operating companies. Over the course of the next 18 months, more operating units will also adopt the Flexitallic master brand.
 
"While each operating company has its unique strengths, we're now collaborating as a global enterprise for the increased benefit of our customers," said Remi Toledano, president and ceo. "Our shared focus on developing products and solutions that deliver uncompromising safety will be a hallmark against which the Flexitallic brand will continue to grow."
 
He emphasises that as the transition occurs, customers will experience the same high-quality responsiveness, service, and support they have come to expect from the organisation, while ordering, fulfilment, and company contacts have not changed.
 
A month earlier, the company acquired Custom Rubber Products, the Houston-based manufacturer of elastomer, phenolics, and thermoset plastic products for upstream and midstream oilfield and industrial markets.
 
"Adding Custom Rubber Products to our portfolio immediately positions FDS as the global leader in static sealing technology across all segments of the energy industry: upstream, midstream, downstream and power generation,” said Toledano. “Its innovative approach to designing and producing highly-specialised solutions, with an uncompromising eye toward reliability and safety, is an ideal fit with other FDS Group companies who operate with the same customer-centric values."
 
This acquisition comes less than a year after FDS's purchase of Canadian manufacturer AGS Group. FDS Group's global network also includes Flexitallic, SIEM, Novus, Induseal and Sealex, with manufacturing operations in the US, Canada, Mexico, UK, France, Germany and China plus licensed production partners worldwide. [Page Break]
 
Seal standardisation strategy saves money
 
Flowserve Corporation is continuing with the global promotion of its ‘Innovative Standard Cartridge’ seal series - the ISC2.
 
Well received by customers in the North American process industries, the company is expanding its promotion of the product into all other global regions. Facilities that standardise with the ISC2 seal can benefit from reduced inventory, greater application flexibility, rapid availability, less downtime and longer seal life, resulting in an overall cost reduction.
 
Designed to fit a wide range of pump designs and configurations, ISC2 seals feature an exclusive, patented thermal management technology which tolerates short-term dry run events without overheating, thereby increasing reliability and preventing a common cause of leakage.
 
ISC2 dual seals employ enhanced barrier fluid circulation for the highest flow rate and coolest running when compared to other standard cartridge seals. ISC2 single seals have a sizeable throttle bushing to help protect against leaks.
 
“Flowserve is an industry leader in the design, production and service of mechanical seals and support systems for pumps and other rotating equipment,” said Ken Lavelle, president, seal operations. “The ISC2 seal offers our customers maximum performance and reliability in a variety of industries and applications and demonstrates our continuing technology leadership and commitment to provide our customers with products and services that meet or exceed their requirements. In fact, this innovative seal design is so versatile, it may be the only pump seal required by some facilities.”
 
Flowserve mechanical seals are designed to prevent the leakage of potentially hazardous process fluids, providing environmentally-conscious companies improved reliability and extended mean time between repair.