The primary purpose of a pressure or vacuum relief valve is to protect life and property by venting process fluid from an overpressurized vessel or adding fluid (such as air) to prevent formation of a vacuum strong enough to cause a storage tank to collapse.
Proper sizing, selection, manufacture, assembly, testing, installation, and maintenance of a pressure relief valve are all critical for optimal protection of the vessel or system.
Please note that the brand names of pressure relief devices covered (Anderson Greenwood, Crosby, Whessoe and Varec) are of Pentair manufacture. A specific valve brand is selected, according to pressure range, temperature range, valve size, industry application and other applicable factors.
This manual has been designed to provide a service to Pentair customers by presenting reference data and technical recommendations based on over 125 years of pioneering research, development, design, manufacture and application of pressure relief valves. Sufficient data is supplied so that an individual will be able to use this manual as an effective aid to properly size and select Pentair-manufactured pressure relief devices for specific applications. Information covering terminology, standards, codes, basic design, sizing and selection are presented in an easy to use format.
The information contained in this manual is offered as a guide. The actual selection of valves and valve products is dependent on numerous factors and should be made only after consultation with qualified Pentair personnel. Those who utilize this information are reminded of the limitations of such publications and that there is no substitute for qualified engineering analysis.
Pentair pressure relief devices are manufactured in accordance with a controlled quality assurance program which meets or exceeds ASME Code quality control requirements. Capacities of valves with set pressures of 15 psig [1.03 barg], or higher, are certified by the National Board of Boiler and Pressure Vessel Inspectors. These attributes are assured by the presence of an ASME Code Symbol Stamp and the letters NB on each pressure relief valve nameplate. Lower set pressures are not addressed by either the National Board or ASME; however, capacities at lower set pressures have been verified by actual testing at Pentair’s extensive flow lab facilities. Pentair’s range of pressure relief valves are designed, manufactured, and tested in strict accordance with a quality management system approved to the International Standard Organization’s ISO 9000 quality standard
requirements. With proper sizing and selection, the user can thus be assured that Pentair’s products are of the highest quality and technical standards in the world of pressure relief technology.
When in doubt as to the proper application of any particular data, the user is advised to contact the nearest Pentair sales office or sales representative. Pentair has a large staff of highly trained personnel strategically located throughout the world, who are available for your consultation.
Pentair has designed and has available to customers a computer sizing program for pressure relief valves, PRV2SIZE (Pressure Relief Valve and Vent Sizing Software). The use of this comprehensive program allows an accurate and documented determination of such parameters as pressure relief valve orifice area and maximum available flow.
This sizing program is a powerful tool, yet easy to use. Its many features include quick and accurate calculations, user-selected units of measurement, selection of pressure relief valve size and style, valve data storage, printed reports, valve specification sheets and outline drawings. Program control via pop-up windows, function keys, extensive on-line help facilities, easy-to-read formatted screens, flagging of errors, and easy editing of displayed inputs make the program easy to understand and operate.
It is assumed that the program user has a general understanding of pressure relief valve sizing calculations. The program user must remember they are responsible for the correct determination of service conditions and the various data necessary for input to the sizing program.
For download instructions for the latest PRV2SIZE please contact your sales representative or factory.
The information in this manual is not to be used for ASME Section III nuclear applications. If you need assistance with pressure relief valves for ASME Section III service, please contact our nuclear industry experts at 508-384-3121.