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Showing posts from May, 2011

John Crane's Type 28 Dry Gas Seals: How Does It Work?

How Does It Work? Highest Pressure Non-Contacting, Dry-Running Gas Seal Type 28 compressor dry-running gas seals have been the industry standard since the early 1980s for gas-handling turbomachinery. Supported by John Crane's patented design features, these seals are non-contacting in operation. During dynamic operation, the mating ring/seat and primary ring/face maintain a sealing gap of approximately 0.0002 in./5 microns, thereby eliminating wear. These seals eliminate seal oil contamination and reduce maintenance costs and downtime. John Crane's highly engineered Type 28 series gas seals incorporate patented spiral-groove technology, which provides the most efficient method for lifting and maintaining separation of seal faces during dynamic operation. Grooves on one side of the seal face direct gas inward toward a non-grooved portion of the face. The gas flowing across the face generates a pressure that maintains a minute gap between the faces, optimizing flui

Dry-Running Sealing Technology: Pump Applications (P2)

Solutions to Common Problems The operation of a single contacting seal would be difficult with any of the identified problems. A single contacting seal relies on cooling and lubrication from the process liquid being sealed. Any interruption in the cooling and lubrication processes will result in damage to the seal and leakage to the environment. The non-contacting, dry-running seal is a solution to many of the problems identified by users. An installation to a pump is illustrated in Figure 2. This type of pump seal technology does not require the circulation of liquid for cooling. Instead, a static heat of an inert gas is used to pressurize the space between the seals. Nitrogen gas in normally used to create the barrier between the process liquid and the environment. The gas barrier pressure is normally 20 to 30 psi/1.4 to 2 bar above the seal chamber pressure.  The spiral groove geometry of the seal face is responsible for lift-off and separation of the seal faces

Dry-Running Sealing Technology: Pump Applications (P1)

Non-contacting, dry-running seal technology, a revolutionary technology for pumping equipment, was developed and pioneered by John Crane and meets the USA Clean Air Act of 1990. This Act defines emission standards for rotating equipment. Designed for emissions control, this sealing concept has resulted in improved reliability, efficiency, and cost benefits when compared to competing technologies such as canned and magnetic drive pumps. A non-contacting, dry-running seal solves the tribological problems when pumping certain fluids rather than transferring those problems to other areas of the equipment as in the case of competing technologies. Many plant operators have a Mean Time Between Planned Maintenance (MTBPM) of less than two years. In some cases, equipment is down for repair every two to three months. This has a major impact on the cost of owning the equipment and may also impact the amount of product being manufactured. By properly applying non-contacting, dry

The problems with KPIs

The reason why we measure performance in organizations is often reduced to simple platitudes, such as, “you can’t manage anything unless you measure it” or “what gets measured gets done.” The three main reasons for measuring performance are: To learn and improve To report externally and demonstrate compliance To control and monitor people. The problems with KPIs Why do we measure performance? In practice, the term ‘KPI’ is overused, and often describes any form of measurement data and performance metrics that measure business performance. Instead of clearly identifying the information needs, and then carefully designing the most appropriate indicators to assess performance, we often observe what we have termed the ‘ICE’ approach: Identify everything that is easy to measure and count Collect and report the data on everything that is easy to measure and count End up scratching your head and thinking, “What the heck are we going to do with all this performance data

What are KPIs?

A key performance indicator (KPI) is a specific measure of an organization's performance in some area of its business. It is a very general concept, with different implementations depending on the type of business and goals of the organization. Examples of KPIs may include such things as the percentage of deliveries made on time, total inventory at any given time, distribution costs as a percentage of total sales, accuracy of invoices sent to clients, or lead time for a product. The purpose of KPIs is to give a business quantifiable measurements of things it has determined are important to its long-term success. Identifying the most important KPIs is the first step towards realizing increased profitability and efficiency for most businesses. For KPIs to be useful, they must be consistently quantifiable, have an established correlation to the area of the business in need of improvement, and not give false readings. - KPIs are utilised to track or measure actual perfor

FMEA Video: How To Perform a Failure Mode and Effects Analysis

FMEA stands for Failure Mode and Effects Analysis. This DMAIC tool is used to evaluate risk in a process. FMEA will help to improve the quality and safety of work tasks. Using this SigmaXL template will allow you to document a baseline for improvement and provide compelling data to confirm a need for changes to the current process. Detection level is critical to quantify the cost of poor quality. You would never want to pass on a defect to a customer or create an environment that puts employees at a risk of injury. FMEA encourages a proactive approach when used to assess risk in newly designed products or processes. This tutorial demonstrates how to use SigmaXL software to record before and after risk levels. View video for more information on this technique. FMEA is an acronym for Failure Mode and Effects Analysis. This video tutorial will teach you what is a Failure Mode and Effects Analysis, when to use FMEA, and show you a template available with SigmaXL software. The goal of