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 Shipping Saddles
How is your equipment making it from Point A to Point B? Please consider shipping saddles as an important part of the design.
Shipping saddles are just what the name sounds like. Saddles created for the sole purpose of transporting equipment. Since they do not remain with the equipment, they are often disregarded as an afterthought.
However, transporting equipment horizontally by truck, train, or barge may put stresses on vertically installed equipment that it was never designed for. It is important to calculate these stresses before placing the equipment on shipping saddles. “We think it will work!” and “We hope it makes it okay…” are not design strategies. Shipping loads should be considered in the original design because it’s the easiest time to fix any issues that may arise.
Each mode of transportation affects equipment stresses differently so each one should be considered individually. Owner/Operators should insist on reviewing these calculations before delivery.
Calculate Required Slotted Bolt Hole Length
Can your saddle bolt holes handle the effects of thermal expansion in your equipment?
Bent saddles and sheared bolts from undersized slotted bolt holes pose a major operational risk that is often overlooked. It is much easier to design for thermal expansion before fabrication than it is to try to fix an inadequate slotted bolt hole length while in service. There is a simple calculation to determine if your slotted bolt hole length is enough to handle thermal expansion at design temperature.
Please review PIP VEFV1100 for more information regarding the design of supports and other attachments.