Abstract: A sucker rod coupling 10 having a high ultimate tensile strength, resistance to corrosion, and resistance to surface cracking arising out of a method of making the sucker rod coupling 10, which employs a five-step process of forming a coupling 10. First, a hollow cylindrical core 12 from a heat treatable steel is formed. Second, a thin coating 18 of metallic alloy is applied to the outer surface of the core 12. Third, the core 12 is heat treated. Fourth, threads 20 are partially cut in the inner surface of the core 12. Fifth, the threads 20 are cold worked to transform the partially cut threads 20 into finished threads 20 and to place the thread roots 22 in compression.

Abstract: A sucker rod coupling 10 having a high ultimate tensile strength, resistance to corrosion, and resistance to surface cracking arising out of a method of making the sucker rod coupling 10, which employs a five-step process of forming a coupling 10. First, a hollow cylindrical core 12 from a heat treatable steel is formed. Second, a thin coating 18 of metallic alloy is applied to the outer surface of the core 12. Third, the core 12 is heat treated. Fourth, threads 20 are partially cut in the inner surface of the core 12. Fifth, the threads 20 are cold worked to transform the partially cut threads 20 into finished threads 20 and to place the thread roots 22 in compression.

Abstract: A sucker rod coupling 10 having a high ultimate tensile strength, resistance to corrosion, and resistance to surface cracking arising out of a method of making the sucker rod coupling 10, which employs a five-step process of forming a coupling 10. First, a hollow cylindrical core 12 from a heat treatable steel is formed. Second, a thin coating 18 of metallic alloy is applied to the outer surface of the core 12. Third, the core 12 is heat treated. Fourth, threads 20 are partially cut in the inner surface of the core 12. Fifth, the threads 20 are cold worked to transform the partially cut threads 20 into finished threads 20 and to place the thread roots 22 in compression.

Abstract: A loading arm utilizing a counterbalancing mechanism in which half sheaves are utilized to provide one interconnection between the counterbalance and the outboard arm and a member is pivotally connected to both the outboard arm and the counterbalance to provide the other interconnection between the counterbalance and outboard arm to provide for full retracted storage of the arm. Preferably, rods provide the majority of the interconnection between the outboard arm and the counterweight.

Abstract: A loading arm having dual inboard and outboard arms and dual connections for connecting the arm to a tank in which provision is made for the loading arm to be connected to side-by-side flanges on the tank and to provide for movement of the connecting system in three mutually perpendicular planes relative to the outboard arm of the loading arm.

Abstract: The coupling disclosed is for attachment to a loading arm and permits attachment of the loading arm to flanges of different diameters by providing adapters which are releasably secured to the coupler. A different size adapter is utilized for each different size flange that the coupler is to be fastened to. The clamp arms move radially outward from the flowway through the coupler to accommodate larger size adapters which fit with larger size flanges to which the coupling is to be attached.