Chapter 2 Installation | Series |
|
|
Installing Flow Meters with a Packing Gland Connection*
Use the formula below to determine the insertion depth for flow meters (NPT and flanged) equipped with an insertion tool. To install, see the next page for instructions for meters with a permanent insertion tool. For meters with a removable insertion tool, see page
Insertion Length Formula
I = F + R + t – 1.35
Where:
I = Insertion length.
F = Distance from the raised face of the flange or top of the process connection for NPT style meters to the top outside of the process pipe.
R = Pipe inside diameter ⎟ 2 for pipes ten inches & smaller.
R = Five inches for pipe diameters larger than ten inches.
t = Thickness of the pipe wall. (Measure the disk
Figure 2-8. Insertion Calculation (Meters with Insertion Tool)
Example 1: Flange Style Meters:
To install a Series 241 Flow Meter into a 14 inch schedule 40 pipe, the fol- lowing measurements are taken:
F | = | 12 inches |
R | = | 5 inches |
t= 0.438 inches
The example insertion length is 16.09 inches.
Example 2: NPT Style Meters:
The length of thread engagement on the NPT style meters is also subtracted in the equation. The length of the threaded portion of the NPT meter is 1.18 inches. Measure the thread portion still showing after the installation and sub- tract that amount from 1.18 inches. This gives you the thread engagement length. If this cannot be measured use .55 inch for this amount.
F | = | 12 inches |
R | = | 5 inches |
t= 0.438 inches
The example insertion length is 15.54 inches.
*All dimensions are in inches.
