Data processing: generic control systems or specific application – Specific application – apparatus or process – Product assembly or manufacturing
Reexamination Certificate
1998-10-27
2001-01-09
Grant, William (Department: 2786)
Data processing: generic control systems or specific application
Specific application, apparatus or process
Product assembly or manufacturing
C700S100000, C700S110000, C700S097000, C705S026640, C705S027200, C705S028000, C705S029000
Reexamination Certificate
active
06173210
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to automated systems for supporting selection of a mechanical seals for equipment. More particularly, the invention relates to automated systems for supporting advertising, selecting, designing, manufacturing and providing post sales service and support for mechanical seals.
BACKGROUND OF THE INVENTION
Sales and marketing of mechanical seals presently involves several activities including seal selection, design and engineering of a seal, manufacturing, and post sales service and support. This process involves many different people to gather, manipulate, interpret and process a variety of kinds of information, and is not an exact science.
A mechanical seal is a shaft sealing device provided to contain process fluids within equipment such as a pump, mixer or other rotary equipment. Mechanical seals are used in operations of a typical processing plant. Significant industries that use seals include: pulp and paper, chemical processing, petroleum chemical, oil refining, food processing, and power and utilities, among others.
There are generally three types of mechanical seals: component (made of several pieces), cartridge (components unitized for one piece) and split seals. Cartridge seals generally are preferred over component seals for several reasons. First, cartridge seals may be installed without significant training. These seals also may be tested before shipping to ensure sealability. However, conversion from a component seal to a cartridge seal for an application involves a complex process of selection of an appropriate seal design.
Because of the variety of applications for seals, selection of a seal involves considering several factors. For example, seals typically are connected to equipment with a rotary shaft (pumps being the most common) for which there are a large variety of commercially available designs with different dimensional profiles. Equipment also may have been modified in the field for several reasons, resulting in a nonstandard dimensional profile. Additional factors are the operating conditions of the equipment, including process fluids and their combinations, and intentional and unintentional changes in the process fluids used in a systems. Aside from selecting a seal that fits the equipment and is suitable for the given operating conditions, costs of the seal and its installation also are factors.
This selection process therefore generally involves highly trained sales engineers with factory support to perform properly the seal selection process. Their training typically includes mechanical and design engineering and chemical engineering. These individuals typically also perform sales, service and support functions. Because of the complexity of the seal selection process, customers tend to be dependent on these sales engineers. This dependency is due to the complexity of part codes for these seals.
The expertise level of a sales engineer is generally dependent on the size of seal manufacturer, years of experience, education and training, resulting in varying competencies. Sales engineers may possess only industry specific expertise, acquired from their experience. Accordingly, without extensive experience, a sales engineer also may be dependent heavily on factory support for assistance in the seal selection process.
Moreover, sales engineers, despite their experience, still may be dependent on factory support because they typically have immediate access to selection information limited to common equipment and process fluids, either in printed or computer-readable text form. Other information, such as application data, engineering data, special pricing and drawings may be available only at the factory, requiring the sales engineer to use factory support to derive seal selections or to interpret the available information and to select a seal. Accurate communication between sales engineers and factory engineers is a critical component of this process.
Depending on the resources available to a manufacturer, which may depend on its size or its number of years in business, factory support may be limited to manually intensive selection methods prone to errors resulting in an informal, unscientific selection process. Even with more sophisticated procedures based on significant amounts of historical information, however, human intervention is generally required for many decisions made between field sales and factory support personnel because of individuals' judgments and perceptions, which may result in inaccurate selections. In particular, a significant amount of human interaction is required to gather, interpret, manipulate and analyze the application data when the sales engineer requires factory support. In particular, the pump and seal dimensions, operating conditions and process fluids affect the selection of materials to obtain maximum seal life. The human interaction involved in current selection methods may result in different recommendations from different individuals, for the same application, of a seal model, optional seal features, materials of construction, seal environmental controls, i.e., piping plans, and various auxiliary devices to be used with the environmental controls. In addition, the likelihood of an error is increased. An error in any stage of the selection process may result in an inaccurate or incomplete sealing solution, which translates into premature seal failure and increased costs.
There are several steps in the seal selection process which typically involve human interaction. One step is identification of the equipment, e.g., a pump or drive motor or other rotary equipment. The methods of identification differ among sales engineers. Example sources of identification information include identification tags on the equipment, maintenance records, engineering records, purchasing records, equipment manufacturer's records or seal manufacturer's records. If these sources provide incomplete information proper equipment identification may be impossible. Even if equipment is properly identified, e.g., by make and model, modifications may have been made to the equipment. A failure to identify such modifications results in an erroneous seal selection. As a result, a trained individual measures the equipment to obtain accurate dimensional data. Dimensional data is commonly collected using forms of varying complexity and completeness. Simple forms tend to be incomplete. Complex forms tend to be subject to interpretation by sales engineers and factory engineers. Both kinds of forms result in errors.
A seal model which is dimensionally compatible for the identified equipment then is selected. In order to make this selection, a sales engineer may refer to information available in a reference guide, or if not identified in a reference guide, performs a dimensional analysis. The dimensional analysis may be performed by the sales engineer or by relying upon factory support. When application data is received at the factory, it is reviewed for completeness and accuracy. If the data is not satisfactory, the process is delayed.
After a dimensionally compatible seal model has been selected, the operating conditions are identified by the sales engineer and are analyzed to confirm that the recommended seal is suitable for the process performed by the equipment. This analysis involves evaluating the operating conditions and the process fluids, with respect to a number of aspects of the seal, including, but not limited to: a metallurgy for general corrosion resistance; a face material combination for lubricity of the chemical and/or corrosion or abrasion resistance; and selection of secondary sealing components, i.e., o-ring elastomers for temperature and chemical resistance.
The operation conditions include but are not limited to: shaft speed as related to seal chamber pressure acting on the seal, i.e., pressure/velocity; stuffing box/seal chamber pressure, which is a function of different pump internal part designs (impellers); shaft speed; pump discharge pressure at outlet nozzle; pump suction p
Bjornson Carl C.
Greenlie David G.
Bahta Kidest
Grant William
Northeast Equipment Inc.
Wolf Greenfield & Sacks P.C.
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