The Control Valve Handbook has been a primary reference since its first printing in. Control Valve Handbook | Table of Contents . Valve Sizing. This valve sizing software program is based on the use 1. Masoneilan Control Valve Sizing .. Note: Within this control valve handbook, the metric factors. Masoneilan Control Valve Sizing Handbook – Download as PDF File .pdf), Text File .txt) or read online.
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Masoneilan Control Valve Sizing Handbook Supplement
An almost universal approach to hanvbook sizing today is through the Cv factor method. This variation in where most of the total drop takes place is one of the most important aspects in choosing the proper valve characteristic for a given process.
Cv values shown are based on ideal flow characteristics.
In Europe, the Kv and Av coefficients are more widely used. This is important because a serious mismatch might cause the system to be unstable and difficult to control effectively.
Proper valve characteristic recommendations are included:. In practice, the gain can and does vary from the theoretical. Valvula masoneilan handbook for control valve sizing Technology. Concentration, as handbbook by analysis such as pH, is best controlled by a valve with an equal percentage characteristic When the ratio of maximum to minimum valve pressure drop at full flow is greater than 2 to 1.
The following paragraphs are discussions of normal control applications encountered in industrial instrurmentation. Size Upper Travel in. Percent of Travel Flow Direction: Cv is a capacity rating coefficient which is defined as the number of U.
MASONEILAN (1998) Control Valve Sizing Handbook
Is it not logical, then, to study the proposed operating conditions with the object of selecting realistic pressure drops from careful engineering surveys of all factors that can affect the proposed valve? The principal use of the equations is to aid in the selection of an appropriate valve size for a specific application. An oversized valve will be ckntrol near the closed position, and the full control range of the valve will not be utilized.
Flow passing into the seats Flow Characteristics: It is possible to establish general guidelines based upon the extensive experience in field startups and troubleshooting. A comprehensive kasoneilan of Cv factor tables for all Dresser Masoneilan valves is included in one handy reference.
MASONEILAN () Control Valve Sizing Handbook
A controller properly adjusted at the high flow rate has too narrow a proportional band setting for stability at low flows. Characteristic curves of hadbook inner valve styles are often consulted in the second method. When the plug throttles very close to the seat, high fluid velocities occur which can cause erosive damage.
They are the dynamic response of the process and the combination of transmitter and primary device. The above recommendations are only as good as the hydraulic analysis of the pressure conditions in the system.
Control Valve Tuning Handbook Masoneilan handbook for control valve sizing. However, one or the other of two standard characteristics linear or equal percentage is practically always suitable for any given process. Dresser Masoneilan valves utilize the surplus pressures even though the popular misconception is that valves create the drop.
This tabulation supersedes all previous listings since many changes were requiered to bring all ratings in line with actual test data taking into account the use of the critical flow factor, Cf.
Minimum valve pressure drop at full flow is occasionally estimated without thorough analysis, and such estimates are often much too low. Although in this example the flow increments are identical, in practice, these values can and do vary from the theoretical.
Some of the factors are for the valve at rated travel, while others relating to the operating conditions are eizing the partially open valve.
hwndbook There are three basic formulas published in the literature from which a value of Cv factor can be obtained:. Additional explanations and supportive information are provided beyond the content of the standards.
A misapplied equal percentage valve characteristic results in increasing valve gain at high flow rates. On the other hand,