Method for forming a sealing element from extruded thermoplastic rods

Patent metadata

Field	Value
Publication number	US-10081128-B2
Application number	US-201515117355-A
Country	US
Kind code	B2
Filing date	Feb 6, 2015
Priority date	Feb 7, 2014
Publication date	Sep 25, 2018
Grant date	Sep 25, 2018

Abstract

Method for forming a sealing element from extruded thermoplastic rods includes the steps of machining one or more extruded thermoplastic rods, each having a first and a second end, in a desired shape; bending the one or more machined thermoplastic rods into a circular structure at ambient temperature while keeping the stress in the one or more thermoplastic rods below the yield point; joining the first and second end faces of the thermoplastic rods to form the sealing element. A method for replacing and repairing a sealing element of a swivel is also described.

First claim

The invention claimed is:

1. Method for forming a sealing element ( 46 , 47 , 58 ) from extruded thermoplastic rods comprising the steps of:
machining one or more extruded thermoplastic rods ( 1 , 56 , 57 ), each having a first and a second end with a first and a second end faces ( 2 , 3 ), respectively, in a desired shape;
wherein the method further comprises the steps of bending the one or more machined thermoplastic rods ( 1 , 56 , 57 ) into an annular structure at ambient temperature while keeping the stress in the one or more thermoplastic rods below the yield point and joining the first and second end faces ( 2 , 3 ) of the at least one bent thermoplastic rod ( 1 ) to form the closed annular sealing element ( 46 , 47 , 58 ).

2. Method according to claim 1 , wherein the ambient temperature is at least 10° C.

3. Method according to claim 1 , wherein the diameter of the sealing element ( 46 , 47 , 58 ) is at least 1 m and a cross-sectional width (W) is at least 4 mm.

4. Method according to claim 1 , wherein the one or more extruded thermoplastic rods ( 1 , 56 , 57 ) are machined by one-step or multi-step milling.

5. Method according to claim 1 , wherein the first and second end faces ( 2 , 3 ) are joined by welding.

6. Method according to claim 1 , wherein the first and second end faces ( 2 , 3 ) are joined by infrared or heated furnace heating.

7. Method according to claim 1 , wherein the thermoplastic material comprises fluorine.

8. Method according to claim 7 , wherein the thermoplastic material comprises PEEK or related materials.

9. Method according to claim 1 , wherein the sealing element ( 46 , 47 , 58 ) has a uniform cross-section.

10. Method according to claim 1 , wherein the sealing element ( 46 , 47 , 58 ) forms the sealing ring for a high-pressure swivel ( 40 ).

11. Method according to claim 1 , wherein the sealing element forms the back-up ring for a high-pressure swivel ( 40 ).

12. Method for replacing or repairing a sealing element ( 46 , 47 ) of a swivel ( 40 ), having an inner and an outer annular wall ( 41 , 42 ), which define an annular chamber there between, at least one annular sealing element ( 46 , 47 ) being located between the inner and outer walls in a swivel groove ( 48 , 49 ), which sealing element comprises an annular structure of a thermoplastic material, comprising the steps of:
displacing the inner or the outer annular wall ( 41 , 42 ) in an axial direction with respect to its adjacent wall,
removing the non-functional sealing element from the swivel groove ( 48 , 49 ) by opening the annular structure of the sealing element, and
replacing the non-functional sealing element by a functional sealing element ( 46 , 47 , 58 ),
wherein the functional sealing element is formed according to claim 1 .

13. Method according to claim 12 , wherein the machined thermoplastic rods are bent into the swivel groove ( 48 , 49 ), optionally cut to length and subsequently the first and second end faces ( 2 , 3 ) of the at least one bent thermoplastic rods are joined to form the closed annular sealing element.

Assignees

• Single Buoy Moorings

Inventors

• Barrabino Eric

Classifications

• B29C66/4324

  for making closed loops, e.g. belts · CPC title

• B29C66/5261

  for forming coaxial connections, i.e. the bars to be joined forming a zero angle relative to each other · CPC title

• B29C65/02

  by heating, with or without pressure · CPC title

• B29C66/929

  characterized by specific pressure, force, mechanical power or displacement values or ranges · CPC title

• B29C66/71

  characterised by the composition of the plastics material of the parts to be joined (welding bar compositions B29C65/125) · CPC title