I have one pulsation dampener and i want to repair it ( i want to design the stude bolt for it)
The pulsation dampener end cap is under 5000 PSI of pressure. Initially,the end cap was held on by 1 1/2" -12 TPI UNF studs, and secured with relevant nuts. The studes have deteriorated, as have the relevant threads in the pulsation dampener. the pulsation dampener is determined to be repairable.
the existing thread have been machined out to a clean bore of 45mm in diameter (no more thread). It is proposed that oversized threads are tapped into the pulsation dampener and new studs are made to suit the oversized thread.
The propsed thread is 1 7/8" - 12 TPI UNF. However if we use this thread size, the distance between the major thread diameter and the pulsation dampener may be too close and cause failure.
The lenght of the thread of the stud, which is secured in the pulsation dampener is
1 3/4" material of the studs is AISI 4140 condition T (quench & tempered between 260 BHN and 320 BHN). The materail of the pulsation dampener is low carbon steel AS3678 grade 250 or equivalents : ASTM A529 or ST44-2.
Now the Question are :
(1) If the propsal goes ahead, what will be the maximum pressure the thread van withstand before failing
(2) if the general consensus is that the major diameter is too large and may cause failure, what TPI (thread per inch) will be suitable and still achieve the required torque, For instance: will a 18 TPI thread form be sufficient? OR can a finer thread form be used?
Machine Design Question
Re: Machine Design Question
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