Pipes and tubular conduits – Distinct layers – With intermediate insulation layer
Reexamination Certificate
2001-12-07
2003-03-04
Hook, James (Department: 3752)
Pipes and tubular conduits
Distinct layers
With intermediate insulation layer
C138S155000, C138S171000, C138S146000
Reexamination Certificate
active
06527015
ABSTRACT:
TECHNICAL FIELD
This invention relates generally to pipe coating. More specifically, embodiments of this invention relate to insulation strata including a layer or layers in each strata, on a pipe's circumference, where such layers may be abrasion resistant, corrosion resistant and provide thermal insulation to the pipe's contents. The insulation may be placed on a pipe's exterior circumference or surface, interior circumference or surface, or both. The pipe or a pipeline including the pipe, is intended for use in fluid transport, generally submerged.
DESCRIPTION
Introduction
Embodiments of my invention concern certain pipe insulation and pipe coatings.
In embodiments of my invention, the insulation strata may be applied to the interior or exterior circumference or surface of pipes or pipelines, or both the interior and exterior circumferences or surfaces. At least a first strata of insulation may be applied to the pipe surface preceded by an optional primer, a second strata applied to the first strata and optionally at least a first layer of an abrasion resistant coating may be applied to the second insulation strata.
In other embodiments of the present invention the first insulation strata may include a Ceramic-Cover™ 100, (manufactured) Therma-Cote Inc. of Atlanta, Ga., USA and may be described as a viscous solution of ceramic and acrylic latex. Or the first insulation strata may include Therma-Coat from Hempel Coatings, Conroe, Tex. The topcoat or abrasion resistant coating, EC-376F, may be manufactured by Industrial Environmental Coatings Corp of Pompano Beach, Fla.
A second strata may include one or more of syntactic plastic foam, such as polyethylene, polypropylene, polyurethane, and the like, and such syntactic foams may include discrete hollow or porous particles formed from another material. Such second strata may be formed in one or more layers.
Embodiments of this invention further include certain methods of applying the insulation strata and the optional coating. Also contemplated are pipes and pipelines coated, on the interior circumference and/or surface, exterior circumference and/or surface, or both, with an optional primer, with the insulation strata and/or the abrasion resistant coating. In an embodiment with both internal and external insulation, the interior and exterior may be the same or different in thickness, number of layers, materials used and the like. The insulation strata and optional abrasion resistant coatings have properties rendering them superior to, and unique from, previously available pipe insulation and coating. The pipe insulation and optional abrasion resistant coatings described herein are suited for use in producing certain classes of insulated, submerged or buried pipes or pipelines. Those skilled in the art will appreciate that numerous modifications to these embodiments can be made without departing from the scope of the invention. For example, although gas and crude oil pipes and pipelines, insulated on their interior or exterior, are discussed herein, the insulated pipelines may be made using combinations of other coatings and other surfaces to be coated. To the extent my description is specific, it is solely for the purpose of illustrating embodiments of my invention and should not be taken as limiting the present invention to these embodiments.
Definition of Terms and Tests
Density:
ASTM D-793
Compressive Strength:
ASTM D-1621
R value, Thermal Resistance
ASTM C-177-85
k, Thermal Conductance
ASTM C-158
Adhesion to Steel
ASTM D-4541
Primer
A water and chemical resistant primer may optionally be applied directly to the surface of the pipe being insulated, between the pipe and a first layer of insulation. When a pipeline is installed offshore on the seafloor it may have high spots and low spots due to the undulation of the seafloor. In the low spots water may accumulate on the interior of the pipe. This water may come from hydrostatic testing of the pipeline or water entrained in the fluids carried by the pipeline. Such water may cause corrosion, called “6 o'clock” corrosion, for its location on the bottom of a pipeline as one would view a cross section. Should water penetrate the layers of insulation and the topcoat on the interior of the pipe, it could cause corrosion, resulting perhaps in a leak. Particularly troublesome is the presence of carbonic acid or hydrochloric acid in the water. Occasionally oil and gas will contain small amounts of corrosive gases such as carbon dioxide or hydrogen sulfide.
When either of these gases are dissolved in water, acid is created that may attack the surface of the pipe possibly causing failure of the pipe. The use of a primer between an insulation layer and the steel pipe surface may mitigate such a problem. Many types of primers are available and will be known to those of ordinary skill in the art, one type is a phenolic primer such as EP-10, which is manufactured by Morton (Reading, Pa.). This primer may be applied at a thickness that may average 1 mil and may be cured in an oven at 300° F. for one hour. Other primers may be used, some of these primers may not require oven curing, but may be air cured.
Insulation
The insulation of embodiments of my invention will include at least a first strata generally the closest of the strata to the pipe, of at least two layers and optionally a second strata of insulation, the second strata being at least one layer, wherein the first strata will be positioned between the pipe and the second strata.
First Strata
In embodiments of the present invention, the first insulation strata may include a Ceramic-Cover™ 100 (CC-100), manufactured Therma-Cote Inc. of Atlanta, Ga., USA, or the first insulation strata may include Therma-Coat coating manufactured by Hempel Coatings, referred to above. Combinations of any such materials are also contemplated. Polyurethane foam (PU), may have a heat or thermal conductance (k) from 0.65 to 0.1 BTU/sq. ft., hr., F.°. The conductance of the insulation of embodiments of my invention will be ≦0.4 BTU/sq. ft. hr F.°, or ≦0.3 BTU/sq. ft. hr F.°, or ≦0.08 BTU/sq. ft. hr F.°, or ≦0.07 BTU/sq. ft. hr F.°, or ≦0.06 BTU/sq. ft. hr F.°, or ≦0.05 BTU/sq. ft. hr F.°, or ≦0.04 BTU/sq. ft. hr F.°, or ≦0.03 BTU/sq. ft. hr F.°, or ≦0.02 BTU/sq. ft. hr F.°, or ≧0.001 BTU/sq. ft. hr F.°, or ≧0.003 BTU/sq. ft. hr F.°, or ≧0.005 BTU/sq. ft. hr F.°. The density of the first strata insulation, excluding the fibrous or non-woven material discussed herein, as determined by ASTM D-792, may be ≧0.1 g/cm
3
, or ≧0.2 g/cm
3
, or ≧0.3 g/cm
3
, or ≧0.35 g/cm
3
, or ≦0.95 g/cm
3
, or ≦0.75 g/cm
3
, or ≦0.65 g/cm
3
-, or ≦0.55 g/cm
3
. The density of common rigid urethane foams is in the range of 0.012-0.025 g/cm
3
. The compressive strength of the first strata insulation of embodiments of my invention, may be ≧100 psi, or ≧200 psi, or ≧400 psi, or ≧800 psi, or ≧1500 psi, or ≧2,000 psi, or ≧2500 psi or ≧3000 psi, or ≧3500 psi, or ≧4000 psi. The compressive strength of rigid urethane foams is in the range of 15-60 psi (10% deflection).
The first insulation strata may be characterized by its R value (Thermal resistance °F. hr ft
2
/BTU) per applied inch. Other types of insulation typically have Thermal resistance as follows: cork board typically has an insulation value of about 3.33 R value per inch; rock cork about 3.9 R value per inch; expanded polystyrene about 3.0 R value per inch; and polyurethane foam 5-9 R value per inch. Such other types of insulation may be utilized in the second insulation strata. The first insulation strata of embodiments of the present invention may be ≧5 R value per inch, or ≧10 R value per inch, or ≧12, or ≧14 R value per inch, or ≧25 R value per inch, or ≧35 R value per inch, or ≧40 R value per inch, or ≧45 R value per inch, or ≧50 R value per inch, or ≧60 R value per inch or ≦400 R value per inch, or ≦300 R value per inch, or ≦200 R value per inch, or ≦150 R value per inch, o
Hook James
Miller Douglas W.
LandOfFree
Insulated pipe does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Insulated pipe, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Insulated pipe will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3079370