Abstract A high-pressure sampling valve for use in transferring a precise volume of sample fluid into a carrier stream of fluid without interrupting the flow of either stream and includes a housing and a rod movably mounted in a circular channel passing through the housing. Three seals forming leaktight seals between the rod and the housing are provided, one located at each end of the housing and one located between the two fluid channels. The rod has at least two passages passing through it, aligned with two fluid channels in the housing, and a diameter such as to provide clearance between the rod and the housing in the region of the fluid channels so that fluid will leak around the rod and dead heading the valve will be avoided. An actuator is provided to move the rod so that the passage in the rod aligned with one of the fluid channels can be aligned with the other fluid channel. By moving the rod, the volume of fluid contained in that passage of the rod aligned with the first fluid channel can be transferred to the stream of fluid passing through the second fluid channel.
The valve of claim 1 wherein: said seals are of the type having two flat metal discs, with holes through their centers of diameters slightly larger than the diameter of said rod, and an elastomeric disc, disposed between said metal discs, with a hole through its center of diameter slightly smaller than the diameter of said rod; said rod passes through the holes in said discs; and said discs are disposed in a manner such that pressure forcing the two metal discs together will force the elastomeric disc to squeeze down on said rod forming a leaktight seal around it.
Claim 2
Dependent Claim
133 words
The sampling valve of claim 2 wherein said housing comprises: a. a first housing part containing said second channel; b. a second housing part containing said third channel, said first and second housing parts being adapted to fit together and to seat said third seal between them; c. a first end plug adapted to fit the exposed end of said first housing part and to seat said first seal; and d. a second end plug adapted to fit the exposed end of said second housing part and to seat said second seal, said first and second housing parts and said first and second end plugs each containing portions of said first channel and each being aligned with the other housing parts to form a single housing with said first channel passing directly therethrough.
Claim 3
Dependent Claim
29 words
The sample valve of claim 1 wherein said passages running from one side of said rod to the other side of said rod are holes passing through said rod.
Claim 4
Dependent Claim
73 words
The sampling valve of claim 4 wherein said rod contains three such said holes, two of which are normally aligned with said second and third channels, and the third of which is disposed in a position such that when said rod is moved to align the hole in said rod normally aligned with said third channel with said second channel, the third hole in said rod will be aligned with said third channel.
Claim 5
Dependent Claim
77 words
The sample valve of claim 4 wherein said rod contains two such said holes and wherein the clearance between said rod and said housing in the region of said third channel is large enough so that the resistance to fluid flow around the rod is substantially equal to the resistance to fluid flow through the rod, whereby the flow of fluid through the third channel is not substantially decreased by reason of the movement of said rod.