Rice Lake Weigh Modules/Mount Assemblies - Manual (Page 34)

2-5
WEIGH MODULES Single-Ended Beams
RL1800 Modules
These modules use single-end beam load cells in center-pivoted
modules with capacities up to 10,000 lb per module. While these
are compression-style modules, the cell is actually mounted in
tension since the load is introduced through a center loading bolt
in a hanging trunnion suspended beneath the load cell. The
trunnion can pivot in all directions on a set of spherical washers,
allowing the top plate (attached to the vessel) to rock without
twisting the load cell. This arrangement makes the modules self-
centering, and able to accommodate movement in all directions.
This module is self-checking and provides lift-off protection.
The RL1800 modules allow the installer to adjust overall height
easily with the center loading bolt that is attached to the hanging
trunnion. This adjustment feature speeds the process of equalizing
the load between all modules. These modules allow load cell
removal and replacement without raising the tank—an important
consideration in some installations.
Allowable Movement
Figure 2-7 illustrates the RL1800 module with arrows indicating
allowable movement.
Figure 2-7: RL1800
Construction and Features
1) A base plate and spacer support the load cell.
2) A trunnion block is suspended below the free end of the cell
and is attached to the cell using a bolt in tension which is
screwed into a threaded load hole. A spherical washer set is
placed between the bolt head and block.
3) A chair arrangement is attached to the trunnion block through
pivot screws, and the load is applied to the top plate of this
chair. This arrangement allows the chair to move in the
directions indicated in Figure 2-7.
4) Because the load is suspended from the underside of the cell,
the module is self-centering; that is, after a disturbance
temporarily moves the top plate laterally, it will tend to return
to its original position under the influence of gravity.
5) The module provides lift-off protection and lateral restraint.
6) The module provides height adjustment.
7) This module can accommodate a broad range of alloy steel,
stainless steel and hermetically-sealed stainless steel load
cells.
8) The RL1800 module is available in capacities from 250 lb to
10,000 lb in both mild steel and 304 stainless steel.
Typical Installation
Loading
Bolt
Figure 2-8: RL1800 modules on
horizontal cylindrical tank