Reciprocating Air Compressors
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- Category: Featured
- Published on Monday, 29 December 2014 08:51
- Written by Super User
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When one thinks of a reciprocating air compressor, they generally pull to mind the old portable compressors that were common tag a longs to power tools. The governor on these traditionally compressors was quite simplistic; they generally only had two main gears. These consisted of an idling gear where the compressor was on and running. There was also a high gear. This gear was engaged when the compressor was actually being used to power a tool or other accessory.
Today's reciprocating air compressors are not too different from these earlier models, though their construction, longevity and other aspects have certainly improved with time. Reciprocating air compressors are also referred to as piston compressors. These units use a piston that moves in a vertical motion, and a crankshaft that moves the piston up and down. The motion of the pistons and the crankshaft are what provides the gaseous materials at a high rate of pressure.
The reciprocating air compressor uses the pistons as the main components to compress the air. As the piston moves in an up and down vertical motion, the air is pushed into a compartment. As the amount of the air increases in the compartment, the pressure on the air builds up. The denser the air becomes, the greater the pressure. When the correct pressure is reached, then it is ready for use.
Compressors are used in a large variety of applications. Oil refineries, factories, and machine shops all have a use for air compressors. For those looking to purchase a compressor, there are a few factors to consider. The first thing that must be determined is how many cubic feet per minute you need for the application you intend to use the compressor for. After this has been determined, then you can start shopping for the ideal air compressor.
There are a variety of reciprocating air compressors to choose from. The air tank size and the number and size of the cylinders are two things that offer a number of different options. Do you need a more portable compressor, or is a larger stand-alone compressor more suited to the environment in which you will be working?. There are also multi-stage units available on the market. These offer multiple cylinders that can compress the air to an even higher density than the single cylinder units.
Customized Air Compressors
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- Category: Featured
- Published on Monday, 22 December 2014 08:48
- Written by Super User
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Customized air compressors have a number of useful benefits and are used every day by a variety of businesses. The majority of air compressors are very durable and can easily be transported.
There are a variety of types of customized air compressors that are used for a variety of useful purposes. Types of air compressors include industrial, portable, dental, electric, and gas as well as diesel air. Customized air compressors vary in price and they can be purchased new or used.
The way in which air compressors work are that they release pressurized air which then can be used in various industries, including industrial manufacturing and processes that make products used every day.
Some of the different types of air compressors are reciprocating, rotary screw, and rotary centrifugal. Air compressors are either positive air placement or dynamic type machines, meaning that they automatically increase air pressure, as well as, elevate the air to a higher pressure.
Most rotary air compressors are comprised of two rotors within a casting device which compresses the air internally. They employ a rotary type positive expulsion system, which conveys pressurized air to power drills, pumps and other types of machinery. There are no valves built within this type of compressor, it is oil cooled.
Dynamic air compressors produce high pressure by the conversion of angular momentum imported by a rotating impeller device. This impeller device must be checked on a regular basis to make sure it is functioning at a normal capacity. Air compressors of this type are also created for a high capacity because the flow through the compression chain or device is continual. These types of compressors are built oil free and very easy to operate as well as maintain.
Air compressors are designed for industrial use, contractors and commercial applications. In addition, air compressors are designed as portable, electric air as well as gas air compressors.
Clients may actually view, as well as, purchase air compressors on line. The Internet gives the client the ability to shop by style, size, CFM as well as price. Customized air compressors are also available.
Air compressors are used everyday in many different industries and applications. Prices on these machine vary according to brand and type.
Aug1 HTML Title
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- Category: Featured
- Published on Wednesday, 28 August 2013 04:08
- Written by Super User
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Company Name
Test Plan
Revision C
1.
Design tag : %_design_%
2.1. Data Entry Blog Tag :- %_blog_%
2.4. Security development tag :- %_development_%
Each payroll clerk will need a userid and password to login to the system. The system will require the clerks to change the password every 30 days.
- Test Strategy Testing Tag :- %_testing_%
The test strategy consists of a series of different tests that will fully exercise the payroll system. The primary purpose of these tests is to uncover the systems limitations and measure its full capabilities. A list of the various planned tests and a brief explanation follows below.
3.1. System Test
The System tests will focus on the behavior of the payroll system. User scenarios will be executed against the system as well as screen mapping and error message testing. Overall, the system tests will test the integrated system and verify that it meets the requirements defined in the requirements document.
3.2. Performance Test %_article_%
Performance test will be conducted to ensure that the payroll system’s response times meet the user expectations and does not exceed the specified performance criteria. During these tests, response times will be measured under heavy stress and/or volume.
3.3. Security Test
Security tests will determine how secure the new payroll system is. The tests will verify that unauthorized user access to confidential data is prevented.
3.4. Automated Test
A suite of automated tests will be developed to test the basic functionality of the payroll system and perform regression testing on areas of the systems that previously had critical/major defects. The tool will also assist us by executing user scenarios thereby emulating several users.
3.5. Stress and Volume Test
We will subject the payroll system to high input conditions and a high volume of data during the peak times. The System will be stress tested using twice (20 users) the number of expected users.
3.6. Recovery Test
Recovery tests will force the system to fail in a various ways and verify the recovery is properly performed. It is vitally important that all payroll data is recovered after a system failure & no corruption of the data occurred.
3.7. Documentation Test
Tests will be conducted to check the accuracy of the user documentation. These tests will ensure that no features are missing, and the contents can be easily understood.
3.8. Beta Test
The Payroll department will beta tests the new payroll system and will report any defects they find. This will subject the system to tests that could not be performed in our test environment.
3.9. User Acceptance Test
Once the payroll system is ready for implementation, the Payroll department will perform User Acceptance Testing. The purpose of these tests is to confirm that the system is developed according to the specified user requirements and is ready for operational use.
4. Environment Requirements
4.1. Data Entry workstations
- 20 IBM compatible PCs (10 will be used by the automation tool to emulate payroll clerks).
- 286 processor (minimum)
- 4mb RAM
- 100 mb Hard Drive
- DOS 3.3 or higher
- Attached to Banyan Vines network
- A Network attached printer
- 20 user ids and passwords (10 will be used by the automation tool to emulate payroll clerks).
4.2 MainFrame
- Attached to the Banyan Vines network
- Access to a test database (to store payroll information transferred from LAN payroll system)
5. Test Schedule
6. Control Procedures
6.1 Reviews
The project team will perform reviews for each Phase. (i.e. Requirements Review, Design Review, Code Review, Test Plan Review, Test Case Review and Final Test Summary Review). A meeting notice, with related documents, will be emailed to each participant.
6.2 Bug Review meetings
Regular weekly meeting will be held to discuss reported defects. The development department will provide status/updates on all defects reported and the test department will provide addition defect information if needed. All member of the project team will participate.
6.3 Change Request
Once testing begins, changes to the payroll system are discouraged. If functional changes are required, these proposed changes will be discussed with the Change Control Board (CCB). The CCB will determine the impact of the change and if/when it should be implemented.
6.4 Defect Reporting
When defects are found, the testers will complete a defect report on the defect tracking system. The defect tracking Systems is accessible by testers, developers & all members of the project team. When a defect has been fixed or more information is needed, the developer will change the status of the defect to indicate the current state. Once a defect is verified as FIXED by the testers, the testers will close the defect report.
7. Functions To Be Tested
The following is a list of functions that will be tested:
- Add/update employee information
- Search / Lookup employee information
- Escape to return to Main Menu
- Security features
- Scaling to 700 employee records
- Error messages
- Report Printing
- Creation of payroll file
- Transfer of payroll file to the mainframe
- Screen mappings (GUI flow). Includes default settings
- FICA Calculation
- State Tax Calculation
- Federal Tax Calculation
- Gross pay Calculation
- Net pay Calculation
- Sick Leave Balance Calculation
- Annual Leave Balance Calculation
A Requirements Validation Matrix will “map” the test cases back to the requirements. See Deliverables.
%_design_%