CN-113251219-B - Nut for engaging a conduit

CN113251219BCN 113251219 BCN113251219 BCN 113251219BCN-113251219-B

Abstract

A nut for engaging a conduit includes a body having a generally cylindrical shape and defining a central opening. A plurality of lugs may extend outwardly from the outer surface of the body and provide one or more impact surfaces. The central opening may include a threaded portion adjacent the first end of the nut and a tapered portion extending from the threaded portion. The tapered portion defines a frustoconical surface that expands the central opening beyond the threaded portion. The tapered portion may terminate at an undercut or flange near the second end of the nut.

Inventors

Z. A. Schramm
B. J. brias
R. E. little Riddell

Assignees

卡特彼勒公司

Dates

Publication Date: 20260508
Application Date: 20210126
Priority Date: 20200128

Claims (13)

1. A hammer nut for connecting two pipe sections used to convey fluids under pressure during oilfield servicing or production operations, comprising: A body having a generally cylindrical shape extending along an axis from a first end to a second end, the body including a sidewall defining an outer surface of the body and a central opening about the axis, the central opening comprising: A cylindrical first surface extending a first distance from a first end of the body; At least one thread formed on the first surface; A second frustoconical surface extending a second distance away from the first surface toward the second end, the second frustoconical surface being angled relative to the first surface along the second distance, the angle being between 2 degrees and 6 degrees, wherein the first distance is 0.5 times to 2.0 times the second distance, and A third surface adjacent the second end, the third surface disposed radially inward of the first and second frustoconical surfaces, and A plurality of lugs extending radially outwardly from an outer surface of the body, wherein a lug of the plurality of lugs comprises a first generally planar impact surface and a second generally planar impact surface, the first and second impact surfaces being generally parallel to the axis and angled relative to one another, the first impact surface being disposed at a first angle relative to a radius of a nut passing through a center of an end face of the lug, and the second impact surface being disposed at a second angle relative to a radius of a nut passing through a center of an end face of the lug, the first angle being different from the second angle.
2. The hammer nut of claim 1, wherein the second frustoconical surface is angled to create a smaller diameter adjacent the central opening of the first end and a larger diameter adjacent the central opening of the second end.
3. The hammer nut of claim 2, wherein the central opening further includes an undercut between the second frustoconical surface and the third surface.
4. A hammer nut as claimed in claim 3, wherein the transition between the second frusto-conical surface and the undercut is a rounded surface.
5. The hammer nut of claim 1, wherein the at least one thread is disposed on the first surface so as to be spaced from the second frustoconical surface a second distance less than the first distance.
6. A hammer nut as claimed in claim 3 wherein said first and third surfaces are generally cylindrical about said axis and said undercut is generally perpendicular to said axis.
7. The hammer nut of claim 1, further comprising at least one rib disposed on an outer surface of the body and extending circumferentially around the sidewall between a first lug of the plurality of lugs and a second lug of the plurality of lugs.
8. The hammer nut of claim 7, wherein the at least one rib has a substantially uniform outer diameter between the first and second lugs.
9. A hammer nut for connecting two pipe sections used to convey fluids under pressure during oilfield servicing or production operations, comprising: A body having a generally cylindrical shape and extending along an axis between a first end and a second end, the body defining a central opening including a threaded surface adjacent the first end and a tapered surface extending between the threaded surface and the second end, the tapered surface being angled relative to the threaded surface, the angle being between 2 degrees and 6 degrees, and a first radius of the tapered surface at a first axial location relatively closer to the first end being less than a second radius of the tapered surface at a second axial location relatively closer to the second end, wherein the threaded surface extends from the first end along the axis a first distance extending from a tip of the threaded surface along the axis a second distance, the first distance being 0.5 times to 2.0 times the second distance; At least one thread formed on the threaded surface, and A plurality of lugs extending radially outwardly from an outer surface of the body, wherein a lug of the plurality of lugs comprises a first generally planar impact surface and a second generally planar impact surface, the first and second impact surfaces being generally parallel to the axis and angled relative to one another, the first impact surface being disposed at a first angle relative to a radius of a nut passing through a center of an end face of the lug, and the second impact surface being disposed at a second angle relative to a radius of a nut passing through a center of an end face of the lug, the first angle being different from the second angle.
10. The hammer nut of claim 9, further comprising at least one rib disposed on an outer surface of the body and extending circumferentially around the outer surface of the body between a first lug of the plurality of lugs and a second lug of the plurality of lugs.
11. The hammer nut of claim 9, wherein the first distance is approximately equal to the second distance.
12. The hammer nut of claim 9, wherein the central opening further comprises: a third surface adjacent the second end and disposed radially inward of the tapered surface, and An undercut between the tapered surface and the third surface.
13. The hammer nut of claim 12, wherein the transition between the tapered surface and the undercut is a rounded surface.

Description

Nut for engaging a conduit Technical Field The present disclosure relates generally to pumping conduits and, more particularly, to nuts for connecting conduit sections for pumping operations. Background Pumping operations in the hydraulic fracturing (or "fracking"), concreting, well servicing, and the like industries may include pumping high viscosity fluids and/or high pressure fluids. Such fluids may be delivered via a conduit that may be subjected to high periodically applied stresses. The conduit is typically made of pipe sections that are connected to each other using threaded nuts. These nuts typically include projecting wings or lugs that provide the ability to apply torque to tighten or loosen the nut. For example, the lugs may provide a surface upon which a large or hydraulic hammer may strike to provide a substantial impact load or torque required to tighten or remove the nut. Conventionally, nuts for such pumping operations have been known to have a limited service life due to the extreme conditions of their use and installation. In general, repeated impacts during nut installation can cause the lugs on the nut to deform. In addition, the nut is prone to cracking when subjected to bending loads in the pipe sections to which it is used to connect, and is prone to fatigue failure when subjected to cyclic pressure loads generated by pumping incompressible fluid at high pressure within the pipe sections. An example of a known wingnut can be seen in WO 2016/205208 ("Witkowski"), which describes a wingnut having a "full root radius" and an "increased wall thickness". Although Witkowski wingnuts may represent an improvement over known wingnuts, they are still ineffective in improving all aspects of the use and operation of the nut. Disclosure of Invention In one aspect of the present disclosure, a nut may include a body having a generally cylindrical shape extending along an axis from a first end to a second end. The body may include a sidewall defining an outer surface of the body and a central opening about the axis. The central opening may include a first surface extending a first distance from a first end of the body, at least one thread formed on the first surface, a second surface adjacent to and extending away from the first surface toward the second end, the second surface being angled relative to the first surface, and a third surface adjacent to the second end, the third surface being disposed radially inward of the first and second surfaces. The nut may further include a plurality of lugs extending radially outwardly from an outer surface of the body. In another aspect of the present disclosure, a nut may include a body having a generally cylindrical shape and extending along an axis between a first end and a second end. The body may define a central opening including a threaded surface adjacent the first end and a tapered surface extending between the threaded surface and the second end. A first radius of the tapered surface at a first axial location relatively closer to the first end is less than a second radius of the tapered surface at a second axial location relatively closer to the second end. The nut may further include at least one thread formed on the first surface, and a plurality of lugs extending radially outwardly from the outer surface of the body. In yet another aspect of the present disclosure, a nut includes a body having a generally cylindrical shape along an axis between a first end and a second end. The body defines a central opening including a generally cylindrical threaded portion adjacent the first end, a frustoconical portion extending from the threaded portion toward the second end, and a third generally cylindrical surface adjacent the second end. The radius of the frustoconical portion is relatively small adjacent the threaded portion and relatively large remote from the threaded portion. The third generally cylindrical portion has a radius less than the radius of the threaded portion. The nut also includes at least one thread formed on the first surface, and a plurality of lugs extending outwardly from the outer surface of the body. Drawings Fig. 1 is a perspective view of a nut according to aspects of the present disclosure. Fig. 2 is a plan view of the nut of fig. 1, according to aspects of the present disclosure. Fig. 3 is a side view of the nut of fig. 1, according to aspects of the present disclosure. Fig. 4 is a cross-sectional view of the nut of fig. 1 taken along section line 4-4 in fig. 2, in accordance with aspects of the present disclosure. Detailed Description The present disclosure relates to conduits for pumping systems, and more particularly, to nuts for connecting sections of pipes or conduits, such as those used in fracturing, concrete pumping, well servicing, oil and gas, construction, and other industries. In the embodiments described herein, a nut may be used on a hammer union to connect two pipe segments for delivering fluids under pressure du