New Version 4.1 (Released January 2012)

Includes many program enhancements and the addition of several new compressor frame models and cylinders which have been recently added to the growing line of compressor products offered by Arrow Engine Company. While on the “Job Summary” screen click on “Compressors” and then “Manufacturer”, then in the “Arrow Frames” grid view the new frame models now available. Click on the row headed to the left of the frame model desired to then view the list of standard cylinder configurations offered. The “Arrow Frames” grid now includes the following models

• VRC2 is Arrow’s original 150 HP frame with 14,000 lb. rod load and available in 1, 2, 3, and 4 stage cylinder configurations
• VRCC is Arrow’s CNG unit with new 150 HP frame rating and 16,000 lb. rod load and available in one cylinder configuration
• VRS2 is Arrow’s new 275 HP frame with 20,000 lb. rod load and available in 1, 2, and 3 stages with cylinders up to 10” diameter
• VRU1 is Arrow’s new Vapor Recovery Unit, 15 HP frame, 10,000 lb. rod load and available as single stage with an 8” or 5” cylinder
• VRU2 is Arrow’s new Vapor Recovery Unit, 30 HP frame, 10,000 lb. rod load and available as two stage with 8” and 5” cylinders

New Version 3.5.0 (Released February. 2011)

• The Arrow, high pressure, CNG compressor has been added to the “Manufacturer” list of “Compressors”. This unit with the 8.5”/4.0”/2.25”/1.125” cylinder configuration can be found by scrolling down to the end of the list.
• Several other four stage cylinder configurations have also been added to the “Manufacturer” list of “Compressors”.
• Compressors with a single cylinder and a “Dummy” cylinder on the opposing throw have been added to the “Manufacturer” list of “Compressors”.
• The program uses a default suction pressure loss based on a percentage of the suction pressure. By clicking on the “?” next to the suction pressure drop input field you can see how this default value is determined. If more accurate pressure drop information is available it can be input to override the default value.
• The cylinder line-up now includes some new higher pressure cylinders such as the 2.25”, 2.375”, and 2.50” cylinders.
• Other minor enhancements include; improved interstage conditions balancing, added cylinder suction preheat, and a revised temperature trails output.
• The performance print-out page now has the new Arrow Compressor Products logo in addition to being able to personalize the page heading with your own contact information which can be entered by clicking on “File” and “User Info.”

New Version 2.3.1 (Released May. 2009)

• Added capabilities for making PDF files of the performance output data sheets
• Expanded the Compressors/Manufacturer models list to include a few single cylinder models
• Upgraded the MAWP rating of the 6.5” & 7.0” double acting cylinders to 400 psi
• Program is now compatible with newer Vista 64 bit processors

New Version 2.2.0 (Released Nov. 2008)

The program now has the capability of adding clearance to the crank-end of any steeple cylinder using valve spacers at 8%, 16% and 24% increments. This will provide better control of the discharge temperature on the second stage of three stage units.

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There are now over 100 possible cylinder configurations listed in the “Manufacturers” list of “Compressors”, making the program more user friendly as customers will rarely need to develop “Program User” configurations and eliminate the risk of creating a configuration that has not been checked by Arrow Engineering to make sure it can be properly balanced.

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Improvements have been made to the “File”/ “Save Job As” function, however, due to changes in format, jobs saved in version 2.1 will not be compatible with version 2.2.

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Other improvements have been made to “ Gas Analysis”, and the “Clearances Fixed”, “Power Fixed”, & “Capacity Fixed” functions available in the drop-down menu to the right of the “CALC Power & Clearances” button. Note that these functions are used only to fine-tune an application for the cylinder configuration selected. Pop-up instructions help explain this.