Emerson Rosemount 5900S Series, Справочное руководство

Страница: 41 / 298

3.2.4 LPG/LNG antenna requirements
Temperature and pressure measurement
Measurements of temperature and pressure is a prerequisite for high accuracy level
measurements in LPG/LNG tanks. A Rosemount Tank Gauging system may include
Rosemount 5900S Radar Level Gauges, Rosemount 2240S Multi-input Temperature
Transmitters, Rosemount 644 Temperature Transmitters as well as pressure transmitters
in order to obtain all necessary measurement variables.
Still-pipe and Verification Pin
A still-pipe must be installed prior to the gauge installation. The still-pipe is customer
supplied and should be manufactured according to the installation drawings.
Three types of steel pipe are recommended:
• DN100
• 4 inch SCH 10 stainless steel pipe
• 4 inch SCH 40 stainless steel pipe
When ordering the level gauge specify the pipe type in the Required System Information
(RSI) form.
The still-pipe must be vertical within ±0.5° and the customer flange must be horizontal
within ±1° as illustrated in
Figure 3-11 .
The still-pipe is manufactured with a number of holes to allow proper circulation of the
product, and to ensure equalization of product density inside and outside the pipe. The
hole diameter should be 20 mm or 3/4”. All holes in the upper still-pipe section must be
placed along a line on one side of the pipe.
The Verification Pin allows you to verify Rosemount 5900S level measurements when the
tank is pressurized. It is mounted on the still-pipe in a hole oriented 90 degrees to the
other holes.
The Verification Pin should be placed at a position of 1200 mm (47 in.) below the flange as
illustrated in
Figure 3-11 . There must be a minimum distance of 200 mm (8 in.) between
the Verification Pin and the maximum product level. In order to fulfill this requirement, the
Verification Pin may be mounted higher, up to 1000 mm below the flange.
The Verification Pin must be aligned with a bolt hole on the still-pipe flange as illustrated in
Figure 3-11 . The Verification Pin’s position must be clearly marked on the still-pipe flange
(see Figure 3-11 ) to allow proper alignment of the Rosemount 5900S gauge.
See installation drawing D9240 041-910 for LPG/LNG Still-pipe for information on how to
install the Verification Pin on the still-pipe. Installation instructions are enclosed with the
Verification Pin and Deflection Plate.
See LPG configuration and the see the Rosemount Tank Gauging System Configuration
Manual for further information on how to configure the Rosemount 5900S for LPG/LNG
measurements.
Reference Manual Installation
00809-0100-5900 September 2019
Rosemount 5900S Radar Level Gauge 41