Torque is the force of rotation, that is, the tightening of the nut. The force of rotation is measured in Newtons per meter - Nm. For flanges that are bolted, the torque produces an axial load on them. Axial load (axial) is the force that acts on the edges of the filter element. It can lead to deformation of the element or leakage. There is a spring effect when the bolts are tightened.
When tightening the nut, the bolt is tightened, the load on the gasket increases. The axial load is directly dependent on the friction force. If it changes, then there will certainly be a change in the load that the gasket experiences. In order for the tightening torque of the bolts to occur in accordance with all the rules, it is necessary to lubricate them together with nuts and washers. The axial load is affected and is an important order in the assembly of the flanges. The torque here is applied with a special torque wrench. Truth,there are more precise methods that affect the torque of the bolts and the final result.
What should be the force on the bolt connection?
The bolt compresses the flanges together. When tightening the bolts, they must be tightened to support the load on the gasket under both temperature and pressure changes during normal operation and when the system is pressurized.
The connection is affected in a certain way by an auxiliary load. Then the bolted connection is able to adapt to any conditions and still remain tight.
The yield strength of the material from which the bolt is made is the load that allows it to be stretched to the maximum allowable length, after which it returns to its original state. Stretching may be in excess of the allowable measure of yield. In this case, when the load is removed, the bolt serves as a kind of "return spring".
When the torque of the bolts is exceeded, the allowable value of the yield strength is stretched, which leads to a decrease in the load. When tightening the bolt, care must be taken so that there is no constriction, which will definitely lead to damage. Bolt torque is a painstaking process, care must be taken to ensure that the total load on the gasket weakens gradually, on a scale of 40-100% of the yield strength. It is also necessary to ensure that the integrity of the gasket, flanges does not change. The voltage that can be applied togasket surface should never exceed the specified value. Proper bolt selection is a prerequisite for a flange connection to work.
How to maintain tightness?
Two conditions to be met:
- The force applied to press the gasket and hold it in place. The load on the bolts must be such that the gasket is compressed against the flange face.
- Force required:
- To pass hydrostatic load.
- The gasket is pressed and held still to prevent pressure from getting inside.
- Keep the load on the gasket after the hydrostatic load is removed.
