Rice Lake RL1800 Series Stainless Steel - Manual (Page 5)

5
vessel to the first pipe support is 20-30 times the pipe diameter. In smaller,
lower capacity tanks and hoppers, isolating the resultant forces becomes
extremely critical. When possible, flexible conduit piping should be used
close to the vessel instead of the rigid variety. For details, see our Weigh
Modules & Vessel Weighing Systems manual, PN 43918.
5. Load cells should not be installed in the modules until all welding is
completed. The heat generated from welding current passing through a
load cell can damage the adhesive holding the strain gauge to the body. If
possible, use a dummy load cell when welding to maintain finished height.
If welding is unavoidable after load cell installation, ground in such a
manner as to prevent welding current from passing through the load cell.
Ground the welder as closely as possible to the point of welding. Never rely
on check rods or piping for grounding.
6. When possible, use only “hermetically sealed” load cells in washdown
applications. “Environmentally protected” load cells are not suitable for
such applications and will be damaged. If tanks and surrounding equip-
ment are frequently steam cleaned, or if the load cell is subjected to direct
washdown, a protective shroud for the weigh module is recommended.
Proper drainage is necessary so the weigh module is not standing in water.
7. Detailed instructions for installing this load cell module follow. When
installing the load cells, use the bolts provided or grade 5 or stronger
hardened bolts. Pay particular attention to the recommended torque
values. Some modules require very loosely torqued bolts to allow the load
cells to flex easily. Others must be very tight to prevent the load cells from
creeping or digging into the module.
2.2 Installing the RL1800 Module
1. The type of installation, structure of the vessel supports, and strength of the
mounting surface govern the method of locating, attaching, and assem-
bling the RL1800 Weigh Module. Carefully consider three areas which
commonly cause accuracy problems:
TOP PLATE LOAD CELL BOLT
LOCK
WASHER
LOAD
CELL
LOAD CELL
MOUNTING
BLOCK
BASE PLATE
JAM NUT
FLAT WASHER
SHOULDER BOLT
CONCAVE WASHER
CONVEX WASHER
LOADING BOLT
UPPER SUPPORT
LOADING BLOCK