Vulcan Offshore Tip #12: Stud Installation

When you replace and install new studs In your Vulcan equipment, there are certain precautions to be observed.

FIG. 1	All Vulcan studs have an unthreaded portion between the two threaded ends. Do NOT install studs using a pipe wrench on the unthreaded portion of the stud. Aside from possible damage to the threads, the marks or notches (Fig. 1) made by the pipe wrench create stress riser points in the stud.
FIG. 2	The accepted method for stud installation is as follows: (1) First thread Jan Nut into stud. (2) Place flat washer on top of Jam Nut. (3) Thread Full Nut onto stud over washer. (Assembly shown in Fig. 2) After assembly, stud may be driven into tapped hole In the casting using either impact wrench or hand wrench. The washer prevents turning of the nuts and reduces thread stresses.
FIG. 3	When installing new studs, care must be taken to assure that the stud Is not over-inserted. NEVER!! insert a stud into a tapped hole to the extent that it bottoms-out. If the stud is bottomed, the thread stresses are mislocated and the probability of stud failure is greatly increased.

Prior to inserting studs, coat the threads with Loctite #271 to assure that studs will remain tight.

Note: This procedure is also detailed in the Onshore Field Service Manual. Click here for the relevant section. The photo below to illustrate the Loctite--not a part of the original tip--was taken during the assembly of the 6300 hammers, and was probably intended to be used in a maintenance tip like this one.