Hexagonal flange face bolt is mainly composed of hexagonal head and flange (hexagonal gasket under the hexagonal fixed connection with the hexagonal) and the two parts of the screw a standard part, its application in the industrial industry is very wide, then in the use of hexagonal flange face bolt, in the end, what tightening methods and requirements? The following Aozhan to explain to you.
Hexagonal flange face bolts tightening method and requirements.
A. Torque-free plum wrench or whack wrench
Suitable for general equipment and pipeline flange tightening, according to the screw size and flange pressure level selection. The tightening requirements are as follows:
1) The maintenance unit should make a tightening plan, tighten the flange symmetrically, and number the tightening sequence.
2) Position the gasket with 4 screws at 1, 2, 3, 4 to ensure that the center of the wound gasket is within the edge of the protruding edge.
3) Tighten the positioning screws by hand, then insert the other stud screws and tighten them to balance the load, making sure that at least 2 threads are exposed at each end of the nut.
4) According to the site equipment and flange, according to the calculation of tightening a circle for once, the number of tightening (at least 3 times) and each tightening whacking load (strength), tightening whacking load (strength) according to the small to large tightening (such as 50%, 80%, 100% increment), do not load load too fast and too large to prevent the gasket seal failure.
5) The order of tightening each time without torque plum wrench or whacking wrench:
a. Tighten the two screws in the radial direction opposite to the established hammering load of the screws (strength);
b. Tighten the other pair of screws about 90 degrees apart from the previous two screws along the circumference;
c, continue to tighten until all the remaining screws are tightened to the established hammering load.
6 ) Finally, tighten all screws in clockwise or counterclockwise direction according to 100% hammering load (strength).
B. Torque wrench
Suitable for high temperature and high pressure, flammable and explosive and other important equipment and pipe flanges. The tightening requirements are as follows:
1) The maintenance unit should make a tightening plan, set the appropriate torque, and review the design according to the screw strength, initial sealing pressure and working sealing pressure of the gasket, medium pressure and other parameters to prevent the screw from breaking and the gasket from losing elasticity due to excessive tightening force, resulting in sealing failure.
2) Fasten the flange symmetrically and number the fastening sequence.
3) Position the gasket with 4 screws at 1, 2, 3 and 4 to ensure that the center of the wound gasket is within the edge of the protruding edge.
4) Tighten the position screws by hand, then insert the other stud screws and tighten them to balance the load, making sure that at least 2 threads are exposed at each end of the nut.
5) According to the site equipment and flange, according to the calculation of tightening a turn for once, the number of tightening (at least 3 times) and each tightening torque should be reasonably set, the tightening torque should be tightened in order from small to large (such as 50%, 80%, 100% increment), and the load should not be too fast and too large to prevent the gasket seal failure.
6) The order of each tightening by torque wrench:
a. Tighten the two screws in radial direction to the established torque of the screws;
b. Fasten the other pair of screws along the circumference of the previous two screws about 90 degrees apart;
c, continue to tighten until all the remaining screws are tightened to the established torque.
7) Finally, tighten all screws in clockwise or counterclockwise direction by 100% torque value.
8) Record the torque value for future maintenance.
The above is a brief introduction of Aozhan on the hexagonal flange face bolts tightening method and requirements, I hope it will be helpful to you. Procurement of hexagonal flange face bolts choose Aozhan hardware bolt products, the choice of stainless steel high-quality materials, complete specifications and sizes, special specifications can be customized, flange face bolts wide range of applications, construction and operation is simple. Can send e-mail: info@aozhanfasteners.com, get preferential quotes, welcome to consult.
Post time: Dec-01-2022
