Method for insulating complex subsea structures

Patent metadata

Field	Value
Publication number	US-2018043584-A1
Application number	US-201615554906-A
Country	US
Kind code	A1
Filing date	Mar 18, 2016
Priority date	Mar 24, 2015
Publication date	Feb 15, 2018
Grant date	—

Abstract

The present invention relates to a process to reduce internal stresses in insulation molded onto complex pipes, preferably complex subsea pipe, to reduce cracking in the molded insulation. Insulation materials applies to complex pipes comprising branches, i.e., valves, and the like, may be susceptible to cracking at, or near where the branch connects to the pipe as the coating of insulation material cures or hardens. The process of the present invention aims to reduce post molded cracking by reducing molded in stress at the branch/pipe junction. This is accomplished by providing a preform at or near a branch/pipe junction prior to applying the coating of insulation material.

First claim

What is claimed is:

1 . A process for insulating a pipe comprising one or more branch comprising the steps of:
(i) providing a preform which is in contact with the pipe and near or in contact with the branch to form a pipe/preform assembly and (ii) molding a layer of insulating material around the pipe/preform assembly.

2 . The process of claim 1 wherein the pipe has one or more branch selected from a tee, a valve, a double valve, a vent, a port, or a flange.

3 . The process of claim 1 further comprising the step of:
(i)(a) adhering the preform to the pipe, the branch, or the pipe and the branch.

4 . The process of claim 1 further comprising the steps of:
(i)(b) positioning a mold around the pipe/preform assembly and
(i)(c) casting the insulating material between the pipe/preform assembly and the mold.

5 . The process of claim 1 further comprising the step of cleaning the pipe prior to providing the preform.

6 . The process of claim 5 further comprising the step of providing a protective coating to the pipe after it has been cleaned but before the preform is provided.

7 . The process of claim 1 wherein the insulating material comprises the reaction product of:
(a) an ambient temperature liquid epoxy-terminated prepolymer and
(b) a catalytic curing agent or a co-reactive curing agent.

8 . The process of claim 7 wherein the co-reactive curing agent comprise a polyamine, a polyamide, a polyaminoamide, a dicyandiamide, a polyphenol, a polymeric thiol, a polycarboxylic acid, an anhydride, a phenol novolac, a bisphenol-A novolac, a phenol novolac of dicyclopentadiene, a cresol novolac, a diaminodiphenylsulfone, or a styrene-maleic acid anhydride (SMA) copolymers.

9 . The process of claim 7 wherein the catalytic curing agent comprise ethyltriphenylphosphonium; benzyltrimethylammonium chloride; a heterocyclic nitrogen-containing catalyst; an imidazole; a triethylamine; or dodecylbenzenesulfonic acid in isopropanol.

10 . The process of claim 7 wherein the insulating material further comprises one or more additional epoxy resin.

11 . The process of claim 1 wherein the insulating material further comprises one or more of a filler, a thickener, a dispersing agent, a pigment, an antistatic agent, a corrosion inhibitor, a preservative, a siliconizing agent, a rheology modifier, an anti-settling agent, or an anti-oxidants.

12 . The process of claim 1 wherein the insulating material is useful for thermal insulation for subsea oil and gas applications.

Assignees

• Dow Global Technologies Llc

Inventors

• Feng Jie
• Brown Mark W
• Chen Xue
• Gupta Pankaj
• Latham Dwight D
• Ma Liangkai
• Malanga Michael T
• Mehta Rujul M
• Vyakaranam Kamesh R
• Wenzel Jeffrey D
• Zawisza Jeffery D

Classifications

• B29C45/0001

  characterised by the choice of material · CPC title

• F16L59/163

  Branch units; Insulation forming a whole with branches · CPC title

• B29C45/14622

  Lining the inner or outer surface of tubular articles · CPC title

• B29L2023/225

  Insulated · CPC title

• F16L59/161

  Housings for valves, tee pieces, or the like · CPC title