Spirax Sarco RIM20, Инструкция по установке и обслуживанию, Страница: 21 / 132

IM-P198-05 MI Issue 2 21
3.9 Installing flowmeters with a packing gland connection*
Use the formula below to determine the insertion depth for flowmeters (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 24.
Fig. 8 Insertion calculation (Meters with insertion tool)
Example 1: Flange Style Meters:
To install a RIM20 flowmeter into a DN350 (14") schedule 40 pipe, the following measurements
are taken:
F = 304.8 mm (12") R = 127 mm (5") t = 11.125 mm (0.438")
The example insertion length is 408.686 mm (16.09").
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 29.972 mm (1.18"). Measure the thread
portion still showing after the installation and subtract that amount from 29.972 mm (1.18").
This gives you the thread engagement length. If this cannot be measured use 13.97 mm (.55")
for this amount.
F = 304.8 mm (12") R = 127 mm (5") t = 11.125 mm (0.438")
The example insertion length is 394.716 mm (15.54").
Insertion length formula
I = F + R + t - 34.29 mm (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
250 mm (10") and smaller.
R = 127 mm (5") for pipe diameters larger
than DN250 (10").
t = Thickness of the pipe wall. (Measure
the disk cutout from the tapping
procedure or check a piping handbook
for thickness.)
FLOW
EXIT EN TER
*
All dimensions
are in mm
(inches)
I
F
R
t
Flow