PIP Slotted Saddle Hole Length Calculation Change
Did you catch the PIP calculation change for the slotted saddle hole length? If not, be sure to update your spreadsheets!
The length of the slotted saddle bolt hole should account for the thermal expansion of the shell at process temperature. Sheared bolts and bent saddles from undersized slotted bolt holes pose a major operational risk that is often overlooked.
Notice that the latest revision to the Process Industry Practices (PIP) standard changed the multiplier from 2 to 2.5. This means that your standard slotted saddle bolt hole lengths may need to increase to stay within the PIP standard.
Please review PIP VEFV1100 for more information regarding the design of supports and attachments.
Calculate Uplift for Bolting
Are your bolts designed to handle the uplift from moments caused by external forces like wind and seismic loads?
I commonly see equipment where only the operating case is checked and I’ve even seen cases where the bolt uplift calculation is ignored altogether. Don’t be fooled into ignoring this simple calculation as catastrophic bolt failure can cause severe damage to your equipment.
The empty condition often governs because process weight helps to prevent uplift. Please calculate all design conditions to determine the governing case.