| 摘要 |
<p>A ram-type blowout preventer having a body with a central bore extending therethrough and with guideways extending outward from the central bore, a ram in each of the guideways and having a recess on its front face, a front packer positioned in said ram recess and including a backing portion and an insert portion, the insert portion being tightly interengaged with said backing portion.</p> |
