Rice Lake Z6 Single-Ended Beam, SS Welded-seal, IP67, OIML C3 - Manual (Page 47)

Attaching Piping to Weigh Vessels 43
20.4 Stay Rods
Stay rods are used to rigidly restrain a vessel in the horizontal
direction. These rods are installed horizontally in tension
\between a bracket on the vessel and a bracket attached to
the vessel’s support structure or foundation. Because of the
negligible deflection of load cells under load, the stay rods will
have little effect on the accuracy of the system when installed
properly. It is necessary to install a number of rods to restrict a
vessel fully in a horizontal plane; see Figure 20-5. On a circular
vessel, the rods should always be tangential. This prevents the
vessel from shifting in any direction, but leaves it free for
thermal expansion/contraction.
Figure 20-6 illustrates stay rods attached to a suspended
vessel. The rods must be horizontal so that they do not affect
the weighing accuracy. Fastening nuts are tightened so the
rod is snug; do not over-tighten. This placement of the nuts
ensures the rods operate in tension and are never subjected
to a compressive or buckling load.
Stay rods are used to:
• Improve system stability and accuracy by limiting
vessel oscillation or vibration.
• Protect piping from fatigue due to constant vessel
movement.
• Ensure the stability of tall slender vessels or vessels
with heavy eccentrically mounted equipment.
• Ensure the stability of vessels against wind, seismic
forces or threat from vehicular traffic.
• Hold a vessel in place when mounted on canister
cells. These cells have very little tolerance of side
forces and must be loaded in the vertical direction
only.
Figure 20-5.
Figure 20-6.
When using stay rods to provide vessel
stability, they are most effective when
attached at or above the center of
gravity of the filled vessel. Stay rods
should be made as long as practical,
as this will be beneficial in reducing forces in the vertical
direction. It should be emphasized that the rods must be
horizontal; for this reason one of the attachment points should
be adjustable in a vertical direction.