Passthrough in Virtualhost not preserving the previous URL

Question

• I have a RewriteRule written at Apache to redirect to TOMCAT.
• Passthrough [PT] doesn't seems to work and Getting Bad Request.
• Same configuration works with [P], but I don't want tomcat PORT to be visible in the browser.
• If I enable ProxyPreserve On, I am getting multiple redirect. Following is the virtualhost configuration in my custom.conf file, included in httpd.conf,

<VirtualHost *:80>
    ServerName xyz
    ServerAlias example.com
    RewriteEngine On
    RewriteRule ^(/web) http://IPaddr:8182 [R=301,L]
    RewriteCond %{REQUEST_URI} !^/web
    RewriteRule ^(.*)$ http://example.com:8080 [PT]
    #ProxyPreserveHost On
    #ProxyRequests On
</VirtualHost>