Bellow Manufacturing & Research, Inc.

Tied Universal Expansion Joints are integrated with tie rods that have been designed into the unit. Pressure thrust is restrained by adding tie rods to the assembly. This expansion joint will accept only small amounts of axial deviation, but it is capable of absorbing large amounts of lateral deviation. The Tied Universal Expansion is unique in that it can accept movement in multiple planes that makes it an excellent expansion joint for floating systems where a primary anchor would not be practical.

mong the many varieties of Bellows available, the most common are metal expansion joints and single metal Bellows. Materials commonly used in manufacturing Bellows include stainless steel, titanium, Monel, and high-performing alloys such as Inconel and Hastelloy. Depending on the application, Bellows can also be fabricated from bronze, aluminum, as well as copper. Stainless steel Bellows manufactured from alloys such as 321, 304, 304L, 316, and 316L are typical. However, for higher stress applications that apply extreme temperatures or pressures on parts, the best solution is often Inconel Bellows. Bellows made of Inconel 600 or 625 not only have higher temperature and pressure tolerance, they actually harden and become stronger over time, due to the material’s unique properties.

Universal Expansion Joints have two separate Bellows in the assembly that are joined by a pipe section in the center. This design allows for large amounts of lateral deflection. Also, the assembly can accept movements axially and laterally. Universal expansion joints must be properly mounted and supported, similar to single unrestrained expansion joints. This expansion joint does not come with pressure resisting hardware.

Refractory Lined Expansion Joints are also meant to endure extremely high temperatures and pressure applications. The refractory lining within the metal expansion joint reduces the pipe wall temperature by 300˚F to 450˚F, depending on the thickness of the refractory lining. The lining also helps to withstand the abrasive material from the catalyst in FCCU applications.

Hinged Expansion Jointed are usually used in a set of two or three, to absorb lateral deflection in one or more direction in a single plane piping system. The Joint in such system is restricted to pure angular rotation by its hinges. Each pair of hinged Expansion Joints, separated by a segment of piping, will act in unison to absorb lateral deflection in much the same manner as a swing or universal Expansion Joint in a single plane application. For a given angular rotation of the individual Expansion Joints, the amount of lateral deflection that a pair of hinged Expansion Joints can absorb is directly proportional to the distance between their hinge pins. In o

The In-Line Pressure Balanced Expansion Joint is used in applications where pressure loading upon piping or equipment is considered excessive or objectionable. The major advantage of the In-Line Pressure Balanced design is its ability to absorb externally imposed axial movement without placing pressure loading on the system. The force resulting from the Bellows spring rate is not eliminated. In fact, it is usually increased over that of a single Expansion Joints. Since both the flow Bellows and the balancing Bellows must be compressed or elongated, and the combined axial force acts upon the piping or equipment. Since the forces that move the Bellows are of a low order of magnitude. These are usually not objectionable, except in cases involving extremely light equipment with close clearance moving parts that might be affected by small forces.