| Hydraulically actuated valve opener. Dartt™ Valve Co., Spring, Texas, offers a
special metal insert which-in its location directly below, and within a housing connnected
to the traveling valve-is exposed to fluid movements as the pump plunger travels up and
down.The solid insert features two "hydraulic amplifiers" that contact the wall
of the housing and are moved upward within the housing on the downstroke by hydraulic
pressure, into enlarged passage- ways in the housing wall that then allow fluid bypass,
Fig. 6. In the same motion, the angled upper tip of the insert is driven upward to contact
and physically unseat the travelling valve ball. This action thus helps open the valve and
prevent gas locking. The second feature of the insert is that on the upstroke, it is moved downward within the housing past the fluid bypasses such that each of the two enlarged diameters sealingly contact the housing wall. This creates multiple secondary seals to backup the traveling valve should it be lodged open by sand. The Dartt valve is installed in the bottom of the conventional double female traveling valve cage by removing the plug that retains the ball and seat, i.e., the unit replaces that plug and is tightened in the same manner as cages. |
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