What is the general procedure for Visa Revalidations?

The Visa Revalidation Application is prepared and sent to the State Department Visa Office lockbox/processing center in St. Louis, MO. which then forwards the application for review to the State Department's Visa Office located in Washington, D.C. Upon receipt of the application, the State Department begins to process the case. Generally, the entire process takes about twelve (12) to fourteen (14) weeks. Note that it is within the discretion of the State Department whether or not to issue the visa.
The State Department is very particular that applications are submitted properly and they will deny applications based on the smallest mistake. For this reason the services of a competent attorney are very valuable.