Pipe Flange Bolts
The suction and discharge pipe connections must be carefully made so as to prevent putting excess stress on either the piping or pump flanges. Incorrect joints lead to problems like leak, creating unplanned down time. As such, fasteners must be the correct grade for the application. Flange bolts are used in such circumstances.
Flange bolts are those type of bolts having a ridge or skirt around the bolt head. They are also know as frame bolts and are designed to provide the holding power as if a washer was installed. The skirt is the distributing agent of the entire clamping load. Pipe flange bolts are widely used in various applications, especially pipe fittings and plumbing. With their multi-feature function, they help make jobs easier and faster. Pipe flange bolts are made from a variety of types and grades to suffice for the various applications flange bolts are used.
- Alloy steel
- Stainless steel
- Carbon steel
- Cast iron
- Bronze etc.
Final torque for the pipe flange bolts is dependent on the type of gasket used. This torque provides the clamp load on the gasket needed for proper sealing. Metallic and spiral type gaskets require greater clamping force than flat rubber gasket material. Higher system pressures lead to increased fastener torques. Pipe flange gaskets are never be used to pull the piping up to the pump. This can stretch the bolt, bend a pipe flange, break the pump casting or bend a suction plate. Rather, pipe flange bolts can fill the gap between the pump and spool piece by using the correct tightening sequence. Pipe flange bolts should be tightened in the correct sequences as illustrated below.