Could you have multiple http-equiv meta elements in one index.htm file, such as:

<meta http-equiv="content-type" content="text/html; charset=UTF-8" />
            <meta http-equiv="expires" content="Fri, 21 Aug 2009 00:15:00 GMT" />
See what I am trying to do here is keep the charset the same, but also have search engines expire the current cache for this site as I have made many changes to my website. It is still under construction and I was wondering if this is the best way to "re-cache" the new content. Specifically, the title, description and keywords meta elements. Any assistance with this would be greatly appreciated.