Low carryover high pressure fluidic fitting

Patent metadata

Field	Value
Publication number	US-9334989-B2
Application number	US-201214122795-A
Country	US
Kind code	B2
Filing date	Jun 7, 2012
Priority date	Jun 20, 2011
Publication date	May 10, 2016
Grant date	May 10, 2016

Abstract

Described is a fitting for coupling fluidic paths which facilitates secure and low leak rate fluid flow through a fluidic path junction such as a junction in a liquid chromatography system or other chemical analysis instrument. Fluid containing various mixtures of chemical samples can pass through the junction at high pressure with little or no trapped residue remaining in a volume at the connection. According to various embodiments, a face seal is achieved between two separate fluidic path features. In some embodiments, the sealing of the fluidic paths is aided by the use of a compliant polymer seal. The seal facilitates intimate contact between adjacent surfaces and significantly limits or prevents the entry of fluid under high pressure into an unswept volume. Thus the risk of carryover and its adverse effect on measurements is reduced or eliminated.

First claim

What is claimed is:

1. A fitting for coupling fluidic paths, comprising:
a coupling body having a threaded bore, tapered cavity and narrow bore for receiving a tube assembly, the tapered cavity extending from an end of the threaded bore and the narrow bore extending from an end of the tapered cavity that is opposite to the threaded bore, the narrow bore having a sealing surface at an end opposite the tapered cavity with a channel extending from the sealing surface to pass a fluid;
a compression screw having an axial bore, a threaded portion in engagement with the threaded bore of the coupling body and a drive surface;
a tube assembly having a sleeve and a tube disposed through the sleeve, the tube having an endface and being secured to the sleeve proximate to the endface, wherein a portion of the tube that includes the endface protrudes from the sleeve, the tube assembly extending through the axial bore of the compression screw; and
a compression member disposed within the tapered cavity and having a tapered face configured to engage a surface of the tapered cavity,
wherein a fluidic seal is formed between the endface of the tube and the sealing surface of the coupling body when the tapered face of the compression member is in contact with the surface of the tapered cavity.

2. The fitting of claim 1 wherein the tube is a stainless steel tube and the sleeve is a stainless steel sleeve.

3. The fitting of claim 1 wherein the compression member comprises at least one ferrule.

4. The fitting of claim 1 wherein the tube assembly comprises a weld at an interface of the sleeve and the tube.

5. The fitting of claim 1 wherein the sealing surface has a conical shape.

Assignees

• Jencks Robert A
• Moeller Mark
• Plant Kenneth R
• Waters Technologies Corp

Inventors

• Jencks Robert A
• Moeller Mark
• Plant Kenneth R

Classifications

• F16L19/0212

  using specially adapted sealing means · CPC title

• F16L19/0206

  the collar not being integral with the pipe · CPC title

• G01N30/6026

  Fluid seals · CPC title

• F16L19/061 Primary

  a pressure ring being arranged between the clamping ring and the threaded member or the connecting member · CPC title

• F16L19/06 Primary

  in which radial clamping is obtained by wedging action on non-deformed pipe ends · CPC title