When discussing mounting kit designs, most of the concerns and conversations revolve around the strength and materials of the bracket and coupling. These components are indeed critical; however, when is the last time you discussed fasteners in detail? These often-overlooked components are trusted to unfailingly connect the bracket between the valve and actuator. VanAire provides correctly graded fasteners and calculates the capability of the fasteners and their resistance to applied loads. These connection points are defined as friction-type shear joints. This bolted joint relies on the frictional force between joint members generated by the fastener clamping force to resist shear forces (e.g., actuator torque and weight).

ISO 12490, 2011 and, API 6DX, 2020 Industry Standards provide direction on how to properly connect a mounting bracket between the valve and actuator.

• Bolting in mounting kits shall not be subjected to shear forces, unless otherwise agreed.
• Bolting of mechanically loaded parts and mounting kit components shall be designed to accommodate the direct loading applied by the actuator design torque/thrust and, if applicable, purchaser-defined external loads (e.g., seismic, blast, structural, snow/ice).
• The threaded portion of bolting shall not be subjected to direct shear due to transverse loading.
• For a valve without an anti-rotation feature (e.g., dowel pin or fitted bolt), the design shall include a calculation of bolt tension to generate a clamping force (e.g., between the valve and actuator, between the valve and mounting kit, and between the actuator and mounting kit) that is sufficient to prevent slippage of bolted connections.