The ASTM D3089-97 (2017) standard specifies a method for determining the AD dimension of an aerosol valve immersion tube. The AD dimension refers to the dimension from the crimped top plane of the valve mounting cup to the centerline at the distal end of the immersion tube. The correct AD dimension helps to ensure that the product can be completely discharged from the dispenser, preventing production problems or sealing problems during the crimping process due to excessive length of the immersion tube. In addition, the appropriate size selection also takes into account factors such as the curvature of the tube, changes in the thickness of the valve cup and valve coaster sheet, and product expansion. This standard applies to the measurement of a 1-inch valve mounting cup.