Valve with body and stem of plastic material

In a valve member for liquid under pressure that includes:

• a body member with an elongated flow chamber therein;
• a controller member with an elongated flow plug of a size adapted for positioning within said flow chamber;
• there being inlet and outlet flow openings including a lateral flow opening in said body member, and inlet and outlet flow openings including a lateral flow opening in said flow plug, such that the lateral flow openings of said plug and body member may be selectively positioned in a flow relationship or a no-flow relationship to each other, upon effecting a relative rotational movement between said members;
• the improvement comprising, in combination:
• at least one of said members being formed of plastic;
• a pair of longitudinally spaced, cylindrical, circumferential lands defined on one of said members, a pair of longitudinally spaced circumferential seals being provided on the other member and adapted for engagement with said lands, to provide spaced rotational seals, between said members in the flow chamber, located on opposite sides of said lateral flow openings and operative to prevent leakage therepast of liquid under pressure;
• a recess defined in the exterior of said flow plug and completely surrounding said lateral flow opening therein, a wiper seal positioned in said recess surrounding said lateral opening in the flow plug and being of a dimension to sealingly engage annular wall portions of the cylindrical flow chamber that surround the lateral flow opening in said body member when the two said lateral flow passageways are aligned in a flow relationship, and to sealingly engage against an annular wall portion of the cylindrical flow chamber that is adjacent but circumferentially offset from the lateral flow opening in said body member when the two said lateral flow passageways are in a no-flow relationship, so that no flow will pass through the lateral flow openings in the flow plug and the body member,
• the recess defined on the flow plug being of channel-shaped cross-section with the web of the channel surrounding the lateral opening through the flow plug, and the wiper seal including a tubular stud that enters the lateral opening in the flow plug.

In a valve member for liquid under pressure that includes:

• a body member with an elongated flow chamber therein;
• a controller member with an elongated flow plug of a size adapted for positioning within said flow chamber;
• there being inlet and outlet flow openings including a lateral flow opening in said body member, and inlet and outlet flow openings including a lateral flow opening in said flow plug, such that the lateral flow openings of said plug and body member may be selectively positioned in a flow relationship or a no-flow relationship to each other, upon effecting a relative rotational movement between said members;
• the improvement comprising, in combination:
• at least one of said members being formed of plastic;
• a pair of longitudinally spaced, cylindrical, circumferential lands defined on one of said members, a pair of longitudinally spaced circumferential seals being provided on the other member and adapted for engagement with said lands, to provide spaced rotational seals, between said members in the flow chamber, located on opposite sides of said lateral flow openings and operative to prevent leakage therepast of liquid under pressure;
• a recess defined in the exterior of said flow plug and completely surrounding said lateral flow opening therein, a wiper seal positioned in said recess surrounding said lateral opening in the flow plug and being of a dimension to sealingly engage annular wall portions of the cylindrical flow chamber that surround the lateral flow opening in said body member when the two said lateral flow passageways are aligned in a flow relationship, and to sealingly engage against an annular wall portion of the cylindrical flow chamber that is adjacent but circumferentially offset from the lateral flow opening in said body member when the two said lateral flow passageways are in a no-flow relationship, so that no flow will pass through the lateral flow openings in the flow plug and the body member,
• the recess defined on the flow plug being of channel-shaped cross-section with the web of the channel surrounding the lateral opening through the flow plug, and the wiper seal being seated against the web of the channel, and the outer face of the seal being in the form of a cylindrical arc of radius corresponding substantially with the radius of curvature of the cylindrical flow chamber to effect sealing therewith.