A dry gas seal is essentially a mechanical seal with a rotating mating ring and a stationary seal ring. Mar 23, 2019 dgs support systems are less elaborate and less expensive than older systems that almost always use oil as a coolant or separating layer in the narrow clearance between stationary and rotating seal components. Dry running seals and gas seals operate on different principles and shall be considered further on. Aug 02, 2017 a barrier seal should be suitable for bidirectional rotation. It is a proven rotating groove technology that reduces steam leakage, compared to traditional sealing devices. Dry gas seals are part of our manufacturing range which are used on high speed compressors in gas and oil industries. Mtbr for dry gas seals mechanical seal engineering engtips. Dry gas seals handbook presenting a complete guide to the technology, from gas seal operation to lessons learned from actual field experience, this practical text will help you make informed decisions regarding application, operation, and maintenance of dry gas seals. Robert flitney, in seals and sealing handbook sixth edition, 2014. Inboard of the dry gas seal is an inner labyrinth seal, which separates the process gas from the gas seal. Dry gas seals are noncontacting, dry running mechanical face seals that consist of a mating rotating ring and a primary stationary ring.
We also offer onsite service and dry gas seal repair. A dry gas seal is a mechanical seal that uses a sealing gas to create a barrier between the process gas and the. Figure 4 grooves in seal mating ring dry gas seal systems the use of dry gas seals requires a system designed to supply sealing gas to the seal as a sealing and working fluid for the running gap. Engineers operators maintenance personnel purchasing personnel technical management the information found in dry gas seals handbook will help you make informed decisions regarding the. The dry gas sealdgs has been widely used in high parameters centrifugal compressor, but the intense vibrations of shafting, especially in. Computational study, dry gas seal, performance, tapered spiral. Common dry gas seal failures are discussed below along with their causes and remedies. Dry gas seal system design standards for centrifugal. As part of the german freudenberg and japanese ekk group, eagleburgmann is one of the worlds leading providers of industrial sealing technology. Repacks sealing solutions are used extensively in highend mechanical seals in single, tandem and double arrangement, as used in turbomachinery and other rotary processing equipment where reliability is paramount and the cost of downtime and consequential losses far outweighs that of using our suitably engineered, flawlessly executed, highperformance products. John crane type 28st dry gas seals ensure reliability and uptime in missioncritical applications. Gas film disturbance characteristics analysis of highspeed and high. Agitated nutsche filters anf boiler feed water seal. Dry gas seals have been applied in process gas centrifugal compressors for more than 20 years.
Figure 2 typical tandem gas seal barrier seal configuration. Mechanical seals are subject to a number of failure modes and hence must satisfy a number of criteria if satisfactory operation is to be achieved. Our mechanical seals are a direct replacement of existing oem seals, designed to fit without any modification of the existing seal. Meco seals contain dry powders and bulk materials, pastes, slurries, vapors, gases, and fluids including aromatic hydrocarbons. The performance of spiral groove dry gas seal under choked. Dry gas seal systems for centrifugal compressors page 2 of. Pdf dry gas face seal design with arbitrary gap shape. Apr 27, 2011 common dry gas seal failures are discussed below along with their causes and remedies. John cranes comprehensive range of dry gas mechanical seals are designed to provide you with the correct seal solution suited for your specific application, to ensure optimal reliability, safety and performance. Shell scotford upgrader design engineering issues and resolutions. The first thing to do is to provide your seal vendor a gas composition so that they can carry out a gas analysis to determine if any liquid will drop out during settle out conditions. The advantages of dry gas seals over wet seal systems can be defined as follows. May 28, 2012 john crane aura dry gas mechanical seals duration.
The use of dry gas seals requires a system designed to supply sealing gas to the seal as a working fluid for the running gap. Hova products are backed up by a team of qualified engineers with longterm experience. In gas seals lubricating oil is not used, thus it can no longer contaminate the process. Dry gas seals are basically mechanical face seals, consisting of a mating rotating ring and a. Many large pumps or compressors contain mechanical gas seals that operate as non contacting, dry running seals. Nov 04, 2016 with aura, operators gain access to localized technical expertise from the largest global service network in the industry with over 200 service engineers located worldwide. Dry gas seals 101 presentation free download as powerpoint presentation. For a more complete description of dry gas seal principles of operation, see shah 1988. Mathematical model of dry gas seal with spiral grooves.
Dry gas seals are in used in compressor stations, processing plants, refineries, chemical plants, and more. Type 28st dry gas seals john crane mechanical seals. John crane gas sealsgas seals and their application for maximum reliability. General this standard covers the minimum dry gas sealing system requirements in association with axial, centrifugal, and rotary screw compressors and expanders for use in the petroleum, chemical, and gas industry services as described in api 617 and api 619. A representative layout of a dry gas seal assembly and basic seal parts are shown in figures 4 and 5. Dry gas seals dgs used in ultrahigh pressure gas reinjection systems are setting a new standard in offshore, deepwater applications. These gas seal systems are normally supplied by the compressor oem mounted on the compressor base plate.
These gas seal systems are normally supplied by the compressor oem mounted adjacent to the compressor. The three principal types of dry gas seals for turbomachinery applications are discussed in the following paragraphs. Drygas mechanical seals set a new standard in deepwater. Three dimensional computational study for spiral dry gas seal. Performance evaluation of bidirectional dry gas seals with special groove geometry. Hova your alternative source for mechanical seal parts. Instead, the lubricating liquid will vaporize as it crosses the seal faces and the leakage is a gas or vapor. When operating, lifting geometry in the rotating ring generates a fluiddynamic lifting force causing the stationary ring to separate and create a gap between the two rings. Dry gas seal systems for centrifugal compressors page 3 of. Despite the 20year trend of increasing dry gas seal applications, and industry accepted standard for gas seal support system design does not exist. Special mechanical seals mechanical seal manufacturers. Centrifugal compressor wet seals seal oil degassing and control. Sanitary models are available for food and pharmaceutical applications. Understanding the dry gas sealing technology and optimizing the seal selection for a given set of operating parameters is crucial for the successful application on rotating equipment.
Dry gas seals are basically mechanical face seals consisting of a mating rotating ring and a primary stationary ring during operation, grooves in the mating ring. Oct 03, 2012 ensure the gas is clean and dryexternal gas for extended reliability filter filtered process gas clean dry seal gas is the module most importantprocess gas gas should be filtered fi fi to around 1 micron coalescing filters can be used to dry the gas heaters can be used to provide superheat heat tracing should be used to. Scribd is the worlds largest social reading and publishing site. With proper application and design however, the leakage is so minute that actual droplets of liquid are not detected. Although the use of dry gas seals dgss in process centrifugal compressors has become an industry standard since the 1980s end users are still facing operational issues related to premature failures which incur significant maintenance and operational costs. Double dry gas seal systems as compared to tandem systems eliminate the following items to. The mechanical oil and gas seal dry gas seal and wet gas seal also has become one of the most important research topics. Dry gas seals operate very similar to a contacting oil seal and pump mechanical seal. If you have a sealing problem, fill out a browse mechanical seals datasheets for meco shaft seals.
Components dry gas seals dry gas seals, an alternative to isosleeve and isocarbon seals, eliminate the need for oil supply systems. Mechanical seal technology and selection eagleburgmann. Dry gas sealing systems for oil sands pumping applications. Inadequate fuel gas pressure during start up typical conditions on inboardoutboard seal will include running. About us at the leading edge of industrial sealing technology. Dry gas sealing solutions for highpressure compressor. Dgs support systems are less elaborate and less expensive than older systems that almost always use oil as a coolant or separating layer in the narrow clearance between stationary and rotating seal components. A free powerpoint ppt presentation displayed as a flash slide show on id. Dry gas seals are mechanical facetype seals available as single, double and tandem models. To reduce the volume of gases containing volatile organic compounds leaking to atmosphere, environmental agencies have instituted regulations limiting voc emissions. Pdf improving dry gas seal reliability researchgate.
Aura the next generation of john crane gas mechanical seals duration. Mechanical seals for oil and gas refinery, petrochemical applications description use of dry gas seals in centrifugal compressors has increased dramatically during the last 20 years because these seals provide many benefits for the end user. Dry gas seal manual valve bearing mechanical scribd. At the same time, people are getting more and more attention on this part, the oil and gas mechanical seal has many advantages, mainly for the reliable sealing performance, a small amount of leakage, the use of a series of.
Figure 7 shows the arrangement of a carbon ring separation seal in a dry gas seal cartridge. Outboard of the dry gas seal is a barrier seal, which separates the gas seal from the compressor shaft bearings fig. Dry gas seals are designed with many of the basic characteristics of liquid mechanical seals and can therefore be potentially subject to similar failure modes. We are committed to providing the latest technologies and designs in order to provide our turbo machinery customers within global energy industries with the solution. Increased safety, lowered maintenance and improved reliability are key considerations for retrofitting with gas seals. A clean and dry separation gas is continuously injected into the barrier seal to protect the migration of lube oil from the outboard bearing housing. Like packing, the mechanical seal faces must also be lubricated. Pdf performance evaluation of bidirectional dry gas. By taking carbon dioxide and hydrogen as lubricating gas, respectively, this paper presents an analysis on the pressure characteristics and temperature distribution of spiral groove dry gas seal which influenced by real gas effect under choked flow condition. Over 80 percent of centrifugal gas compressors manufactured today are equipped with dry gas seals. Dry gas seals 101 presentation gas compressor bearing. Dry gas seal, coincident with pump failures in vertical inline pumps. Once this is established and the gas panel is suitably designed to provide continious dry clean gas these seals can run for many years trouble free. Dry gas seal mechanical seal manufacturers seals leak.
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