Method and apparatus to assemble a high purity liquid distribution system
AssigneeFit-Line, Inc.
InventorFrank F. Hayes, JR.
Life of this patent
Estimating the term…
Abstract
A method and apparatus for assembling a high purity liquid distribution system is described. A distal end portion of the tube is heated then pushed over a sleeve so that the distal end portion can have a shrink seal fit over the sleeve to mitigate accidental or inadvertent pull out of the tube from a fitting. Other benefits are also achieved such as minimal flow restriction of the liquid flowing through the joint and the tube.
Claims13
A method of joining a tube fabricated from a PFA material to a sleeve which is fabricated from a PFA material, the method comprising the steps of:
- heating a heating body to at least 15 degrees Celsius below a softening temperature of PFA material;
- disposing a distal end portion of the tube in a hole formed in the heating body until the distal end portion of the tube is in a pliable state;
- disposing a sleeve on a cylindrical post of a mandrel;
- gripping the tube with a hand;
- while gripping the tube with the hand, pulling the distal end portion of the tube out of the hole of the heating body;
- within 10 seconds after the removing step, pushing the distal end portion of the heated tube over the cylindrical post and the sleeve;
- within 10 seconds after the pushing step, removing the attached tube and sleeve immediately from the cylindrical post of the mandrel;
- allowing the distal end portion of the tube to remain in air which has a temperature between 15 degrees Celsius and 38 degrees Celsius until a temperature of the distal end portion of the tube is below 38 degrees Celsius.
A machine for mounting a tube to a sleeve, the machine comprising:
- a heating body with a hole having an inner diameter larger than an outer diameter of the tube and the hole having a depth greater than ¾ of a length of the sleeve;
- a heater in heat communication with the heating body to transfer heat to the heating body from the heater to raise a temperature of the heating body to about a softening temperature of the material of the tube;
- a controller in electrical communication with the heater and operative to turn the heater on and off;
- a mandrel adjacent to the controller, the mandrel having a cylindrical post defining an outer diameter smaller than an inner diameter of the tube.
A method of attaching a tube to a fitting, the method comprising the steps of:
- providing the tube disposed over a sleeve, the sleeve and the tube when joined to each other defining mating pressing surfaces that extends between a base and apex of an enlarged portion of the sleeve and have a conical configuration, the mating pressing surfaces of the tube and the sleeve being connected to each other over at least 75% of a length of a conical surface of the sleeve;
- inserting the tube and the sleeve into the fitting;
- threading a nut onto a thread of the fitting so that a pressing surface of the nut contacts and pushes against an outer surface of the tube aligned to the mating pressing surfaces
- torqueing down the nut onto the fitting;
- increasing the connection between the tube and the sleeve at the conical surface by torqueing down the nut onto the fitting to a predetermined level.
Dependencies are inferred from the claim text.