Helical strake attachment for tubular structural members

A helical strake pole system that includes a tubular pole having a longitudinal axis and threaded attachment points. The system further includes a helical strake fin disposed circumferentially around a portion of the tubular pole along the longitudinal axis. The system further includes couplers disposed on the tubular pole. The couplers are configured such that each coupler has a first portion with a slot configured to receive an upper portion of the helical strake fin and a second portion configured to removably coupled to a threaded attachment point of the tubular pole. In addition, each coupler is configured to position a portion of the helical strake fin substantially perpendicular to a surface of the tubular pole.

TECHNICAL FIELD

This disclosure relates generally to an attachment for pole systems, and more specifically to systems and methods for installing helical strakes onto tubular members.

BACKGROUND

Tubular members are prone to induced vibrations. For example, vibrations can be caused by current flow in water or by wind flow on land. Wind induced vibration of a tubular structural member can produce vibrations that adversely affect the member and its function. Classical vortex-induced vibration results from vortex shedding. In this type of vibration, vortices are created that shed off a member in a rhythm or at a constant frequency when wind flows across the member. Vortices can result in movement of the member in a direction 90 degrees to the direction of flow. When the vortex shedding frequency becomes close to a natural frequency of vibration of the member, then lock-in can occur which may result in large amplitudes and potentially damaging vibrations.

Helical strakes have been successfully utilized on chimneys, smoke stacks, pipelines, and flare stacks in refineries to reduce the potential for vortex-induced vibrations. Typically, helical strakes consist of a thin plate bent to helically wrap around the tubular member. Conventional attachment of strakes requires layout and welding of the strakes to a tubular member in the field. This process involves significant field labor, construction time, and expense. Shipping strakes pre-welded to a tubular member is undesirable due to potential shipping damage to the thin strakes and handling concerns. Thus, it is desirable to provide an improved method for attaching helical strakes to tubular members.

SUMMARY

In one embodiment, the disclosure includes a helical strake pole system that includes a tubular pole having a longitudinal axis and threaded attachment points. The system further includes a helical strake fin disposed circumferentially around a portion of the tubular pole along the longitudinal axis. The system further includes couplers disposed on the tubular pole. The couplers are configured such that each coupler has a first portion with a slot configured to receive an upper portion of the helical strake fin and a second portion configured to be removably coupled to a threaded attachment point on the tubular pole. In addition, each coupler is configured to position a portion of the helical strake fin substantially perpendicular to a surface of the tubular pole.

In another embodiment, the disclosure includes a helical strake pole assembly method. The method includes positioning a helical strake fin circumferentially around a portion of a tubular pole along a longitudinal axis of the tubular pole. The method further includes attaching a plurality of couplers to the tubular pole such that each coupler positions a portion of the helical strake fin substantially perpendicular to a surface of the tubular pole. Attaching a coupler to the tubular pole involves positioning a first portion of the coupler to interface with the helical strake fin and removably coupling a second portion of the coupler to a threaded attachment point of the tubular pole.

Various embodiments present several technical advantages, such as a system that allows allow helical strake fins to be attached to tubular members without requiring welding. A helical strake fin is attached to a tubular member using a coupler. The coupler is configured to be adjustable to accommodate the effects of taper in the tubular member and for inconsistencies in the bend and pitch of the helical strake fin.

Certain embodiments of the present disclosure may include some, all, or none of these advantages. These advantages and other features will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings and claims.

DETAILED DESCRIPTION

Disclosed herein are various embodiments for coupling a helical strake fin to a tubular member. Conventional strake attachment systems require layout and welding of the strakes to a tubular member in the field. This process involves significant field labor, construction time, and expense. Shipping strakes pre-welded to a tubular member is undesirable due to potential shipping damage to the thin strakes and handling concerns. In contrast, the techniques and system disclosed herein allow helical strake fins to be attached to tubular members without requiring welding. A helical strake fin is attached to a tubular member using a coupler. The coupler is configured to be adjustable to accommodate the effects of taper in the tubular member and for inconsistencies in the bend and pitch of the helical strake fin.

FIG. 1is a perspective view of an embodiment of a helical strake pole system100. The helical strake pole system100comprises a tubular pole102, one or more helical strake fins104, and a plurality of couplers106.

The one or more helical strake fins104may be positioned circumferentially around the outer diameter of the tubular pole102. A helical strake fin104may be configured to have any suitable length and height which extends radially outward from the surface of the tubular pole102. In addition, a helical strake fin104may be configured with any suitable pitch along the length of the tubular pole102. A helical strake fin104may be formed of a metal (e.g. steel or aluminum), a composite (e.g. fiberglass), or any other suitable material as would be appreciated by one of ordinary skill in the art upon viewing this disclosure.

Each coupler106is configured to attach to the tubular pole102and to attach or support a helical strake fin104. The couplers106may be formed of a metal (e.g. steel or aluminum), a composite (e.g. fiberglass), or any other suitable material as would be appreciated by one of ordinary skill in the art upon viewing this disclosure. Examples of couplers106are described inFIGS. 2, 3A-3C, 4A-4C, and 5A-5E.

An example of the tubular pole102includes, but is not limited to, an electric power transmission pole. In other examples, the tubular pole102may be any other suitable type of tubular structural member for above ground or underwater applications. The tubular pole102have any suitable length and diameter (e.g. inner diameter and outer diameter). The tubular pole102may be formed of a metal (e.g. steel or aluminum), a composite (e.g. fiberglass), or any other suitable material as would be appreciated by one of ordinary skill in the art upon viewing this disclosure. The tubular pole102comprises a plurality of threaded attachment points105disposed circumferentially around the tubular pole102and along its longitudinal axis101. The threaded attachment points105provide an interface for coupling couplers106to the tubular pole102. An example of a threaded attachment point105includes, but is not limited to, a threaded bolt hole, a threaded bolt, or a nut welded onto the tubular pole102. The tubular pole102may comprise any suitable number of threaded attachment points105which may be distributed anywhere along the surface of the tubular pole102. Examples of using the threaded attachment points105to couple the helical strake fin104and the couplers106to the tubular pole102are described inFIGS. 2, 3A-3C, 4A-4C, and 6.

FIG. 2is a partial cutaway view of an embodiment of a coupler106for attaching a helical strake fin104to a tubular pole102. A portion202of the coupler106is configured to be removably coupled to a threaded attachment point105of the tubular pole102. For example, the portion202may comprise one or more holes, slots, or openings that allows bolts204to pass through the coupler106to for attaching the coupler106to the tubular pole102. In this configuration, the coupler106is attached to the tubular pole102using threaded attachment points105on opposing sides of the helical strake fin104. In one embodiment, the coupler106may be attached to the threaded attachment points105using bolts or screws204. In other embodiment, the coupler106may be attached to the threaded attachment points105using nuts when the threaded attachment points105are threaded bolts protruding from the tubular pole102. In other embodiments, the coupler106may be attached to the threaded attachment points105using any other suitable technique for removably coupling the coupler106to the tubular pole102. In one embodiment, the portion202of the coupler106may comprise slotted openings that allow the position of the coupler106to be adjusted before securing the coupler106using bolts204. For example, the coupler106may be rotated with respect to the surface of the tubular pole102to compensate for inconsistencies with the helical strake fin104before securing the coupler106to the tubular pole102.

Another portion206of the coupler106is configured to receive and/or support the helical strake fin104. The helical strake fin104is positioned within a groove, crimp, slot, or recess203of the coupler106. The coupler106is configured to position the helical strake fin104to be substantially perpendicular to the surface of the tubular pole102. In other words, the coupler106positions the helical strake fin104such that it extends radially away from the surface of the tubular pole102. In one embodiment, the coupler106may be formed using a pliable or semi-rigid material (e.g. aluminum) that allows the coupler106shape to be manipulated to compensate for inconsistencies in the bend and pitch of the helical strake fin104.

FIG. 3A-3Care partial cutaway views of other embodiments of a coupler106for attaching a helical strake fin104to a tubular pole102. InFIGS. 3A-3C, the coupler106is configured to attach to the tubular pole102on one side of a helical strake fin104.

InFIG. 3A, a portion302of the coupler106is configured to be removably coupled to a threaded attachment point105of the tubular pole102. For example, the portion302may comprise a hole, slot, or opening configured similar to the coupler106described inFIG. 2. In one embodiment, the coupler106may be attached to the threaded attachment points105using bolts or screws204. In other embodiments, the coupler106may be attached to the threaded attachment points105using any other suitable technique for removably coupling the coupler106to the tubular pole102. In one embodiment, the portion302of the coupler106may comprise slotted openings that allow the position of the coupler106to be adjusted before securing the coupler106using bolts204. For example, the coupler106may be rotated with respect to the surface of the tubular pole102to compensate for inconsistencies with the helical strake fin104before securing the coupler106to the tubular pole102.

Another portion304of the coupler106is configured to receive and/or support the helical strake fin104. The helical strake fin104is positioned within a groove, crimp, slot, or recess203of the helical coupler106. The coupler106is configured to position the helical strake fin104to be substantially perpendicular to the surface of the tubular pole102. In other words, the coupler106positions the helical strake fin104such that it extends radially away from the surface of the tubular pole102. In one embodiment, the coupler106may be formed using a pliable or semi-rigid material (e.g. aluminum) that allows the coupler106shape to be manipulated to compensate for inconsistencies in the bend and pitch of the helical strake fin104. InFIG. 3A, the portion304of the coupler106configured to receive the helical strake fin104substantially covers one side of the helical strake fin104and only partially covers the opposing side of the helical strake fin104. In other embodiments, the portion304may be configured to cover or support any other suitable amount of the sides of the helical strake fin104.

InFIG. 3B, the coupler106is configured similar to the coupler106described inFIG. 3A. In this embodiment, the portion304of the coupler106configured to receive the helical strake fin104substantially covers both sides of the helical strake fin104. In one embodiment, the coupler106comprises one or more openings for allow bolts204to pass through the coupler106to secure the helical strake fin104within the slot203of the coupler106. For example, the coupler106may be configured to receive a first bolt204A for securing the coupler106to the tubular pole102and a second bolt204B (e.g. a set screw) for coupling the helical strake fin104to the coupler106. Adjusting the second bolt204B applies a force onto the helical strake fin104to couple the helical strake fin104to the coupler106. In this configuration, the coupler106provides mechanical interface for coupling the helical strake fin104with the coupler106. In some embodiments, the coupler106may use multiple set screws to apply a force onto the helical strake fin104.

FIG. 3C, is a perspective view of the coupler106described inFIG. 3B. In this embodiment, the coupler106comprises a single opening306for receiving a bolt204to attach the coupler106to a tubular pole102. In other embodiments, the coupler106may comprise any other suitable number of openings306for receiving bolts204to attach the coupler106to a tubular pole102.

FIGS. 4A-4Care partial cutaway views of other embodiments of a coupler106with a threaded portion. InFIGS. 4A-4C, the coupler106is configured to employ a threaded portion that allows the coupler106to adapt to variations in the height a helical strake fin104.

InFIG. 4A, a portion402of the coupler106is configured to be removably coupled to a threaded attachment point105of the tubular pole102. For example, the portion402may comprise a hole, slot, or opening configured similar to the coupler106described inFIG. 2. In one embodiment, the coupler106may be attached to the threaded attachment points105using bolts or screws204. In other embodiments, the coupler106may be attached to the threaded attachment points105using any other suitable technique for removably coupling the coupler106to the tubular pole102. In one embodiment, the portion402of the coupler106may comprise slotted openings that allow the position of the coupler106to be adjusted before securing the coupler106using bolts204. For example, the coupler106may be rotated with respect to the surface of the tubular pole102to compensate for inconsistencies with the helical strake fin104before securing the coupler106to the tubular pole102.

Another portion404of the coupler106is configured to receive and/or support the helical strake fin104. The helical strake fin104is positioned within a groove, crimp, slot, or recess203of the coupler106. The coupler106is configured to position the helical strake fin104to be substantially perpendicular to the surface of the tubular pole102. In other words, the coupler106positions the helical strake fin104such that it extends radially away from the surface of the tubular pole102. In one embodiment, the coupler106may be formed using a pliable or semi-rigid material (e.g. aluminum) that allows the coupler106shape to be manipulated to compensate for inconsistencies in the bend and pitch of the helical strake fin104. InFIG. 4A, the portion404of the coupler106configured to receive the helical strake fin104only partially covers the sides of the helical strake fin104. In other embodiments, the portion404may be configured to cover or support any other suitable amount of the sides of the helical strake fin104.

The coupler106further comprises a threaded portion406. In one embodiment, the threaded portion406may be provided by the bolt204used to attach the coupler106to the tubular pole102. In another embodiment, the threaded portion406may be provided using a different bolt or threaded rod. The threaded portion406is configured to adjust the position of the portion404of the coupler106with respect to the length of the threaded portion406. In other words, the threaded portion406allows the coupler106to adapt for short or taller helical strake fins104. This feature allows the coupler106to be adjusted to compensate for inconsistencies in the height of the helical strake fin104.

InFIG. 4B, the coupler106is configured similar to the coupler106described inFIG. 4A. In this embodiment, the portion404of the coupler106configured to receive the helical strake fin104covers of the surface of the helical strake fin104on both sides of the helical strake fin104. In some embodiments, the coupler106comprises one or more openings for allow bolts204to pass through the coupler106to secure the helical strake fin104within the slot203of the coupler106similar to the configuration described inFIG. 3B. In this configuration, the coupler106provides mechanical interface for coupling the helical strake fin104with the coupler106.

InFIG. 4C, the coupler106is configured similar to the coupler106described inFIG. 4A. In this embodiment, the portion404of the coupler106comprises a first slot203A configured to receive a first portion (e.g. an upper portion) of the helical strake fin104and a second slot203B configured to receive a second portion (e.g. a lower portion) of the helical strake fin104. The first slot203A and the second slot203B may be configured to cover any suitable amount of the surface of the helical strake fin104. In this configuration, the coupler106provides support at both ends of the helical strake fin104for coupling and maintaining the position of the helical strake fin104with respect to the tubular pole102.

FIGS. 5A-5Eare perspective views of embodiments of a coupler106. In one embodiment, the couplers106illustrated inFIGS. 5A-5Emay be used and configured similar to the couplers106described inFIGS. 2, 3A-3C, and 4A-4C.

FIG. 6is a flowchart of an embodiment of a helical strake pole assembly method600. Method600may be implemented by a technician or installer to attach a helical strake fin104to a tubular pole102. In one embodiment, the technician may attach the helical strake fin104to the tubular pole102in the field or at a work site. In other embodiments, the technician may attach the helical strake fin104to the tubular pole102at a different location before delivering the helical strake pole system to a distributor, an end-user, or work site. The assembled helical strake pole system may employ couplers106similar to the couplers106described inFIGS. 2, 3A-3C, 4A-4C, and5A-5E and/or similar variations.

At step602, a technician positions a helical strake fin104circumferentially around a portion of a tubular pole102. The technician positions the helical strake fin104around the outer diameter of the tubular pole102. Any suitable length of the helical strake fin104may be disposed onto the tubular pole102.

At step604, the technician positions a first portion of the coupler106to interface with the helical strake fin104. For example, the technician may position a portion of the helical strake fin104within a slot203of the coupler106. The slot203of coupler106may partially or substantially cover the sides of the helical strake fin104.

In one embodiment, the technician may install or adjust a set screw204in the first portion of the coupler106to couple the helical strake fin104with the coupler106. In this example, adjusting the set screw applies a force onto the helical strake fin104to couple the helical strake fin104to the coupler106.

In one embodiment, the technician may adjust the height of the first portion of the coupler106with respect to a threaded portion of the coupler106. In this example, the technician may raise or lower the height of the first portion of the coupler106to interface and secure the helical strake fin104.

At step606, the technician couples a second portion of a coupler106to a threaded attachment point105of the tubular pole102. For example, the technician may use one or more bolts204to removably couple the coupler106to the tubular pole102, and thereby, couple the helical strake fin104to the tubular pole102. The coupler106may be fastened to the tubular pole102on one or both sides of the helical strake fin104. The technician may rotate the first portion and/or the second portion of the coupler106about the threaded attachment point105prior to securely fastening the coupler106to the tubular pole102. In some embodiments, the technician may apply adhesive or a thread locker to the threaded attachment points105to provide a more secure connection between the threaded attachment points105and the bolts204.

The technician may repeat steps604and606any suitable number of times to attach additional couplers106to the tubular pole102to support the helical strake fin104.