Patent ID: 7033256

Claim:
A valve adapted to control a flow of abrasive particles suspended in a pressurized carrier liquid, the valve comprising: at least two apertured valve seat means; each said seat means having a contact face in contact with a corresponding opposing contact face of another said apertured valve seat means and being translationally slideable in contact therewith and with respect thereto between a first position in which the apertures of each valve seat means are aligned so that said pressurized carrier liquid is passable through said apertures, and a second position wherein the aperture in one valve seat means is blocked by the contact face on another to stop flow through the valve; an elongate tubular strut means bearing at a first end thereof on a first of said valve seat means; said valve seat means being urged sealingly together by the pressure of the carrier liquid exerted on a second end of the strut means remote from the first and transmitted generally longitudinally of the strut means to said first valve seat means; the flow of abrasive particles and carrier liquid being passed to the valve seat means through said tubular strut means; and each said valve seat means comprising a material with a hardness, as measured on the Mohs scale, of at least 9.