638 velocity and pressure change through a

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: m Eq. (6.125) is the desired solution to the fluid-metering problem. The mass flow is related to Q by m ˙ Q (6.131) and is thus correlated by exactly the same formulas. Figure 6.39 shows the three basic devices recommended for use by the International Organization for Standardization (ISO) [31]: the orifice, nozzle, and venturi tube. Thin-plate orifice. The thin-plate orifice, Fig. 6.39b, can be made with in the range of 0.2 to 0.8, except that the hole diameter d should not be less than 12.5 mm. To measure p1 and p2, three types of tappings are commonly used: | v v 398 | e-Text Main Menu | Textbook Table of Contents | Study Guide 6.10 Fluid Meters 399 Ellipse 2d 3 d Bevel angle: 45° to 60° 0.6 d d Flow D d Flow Edge thickness: 0.005 D to 0.02 D t2 < 13 mm Plate thickness: up to 0.05 D t1 < 0.15 D (b) (a) ISA 1932 nozzle shape Fig. 6.39 International standard shapes for the three primary Bernoulli obstruction-type meters: (a) long radius nozzle; (b) thinplate orifice; (c) venturi nozzle. (From Ref. 31 by permission of the I...
View Full Document

{[ snackBarMessage ]}

Ask a homework question - tutors are online