The objective of this web site is to present a brief summary with basic information, ideal for a speedy and efficient solution to any problems with the machinery, in which metallic bellows or bellows joints are used.
Because of our great variety of products, it is quite impossible to include them all in this web cite.
Usually, the applications of bellows include conditions that cannot be met by a mass production with constant general formulae. In this case, we are at our client’s disposal for the construction of special bellows or their application.
Before any doubts might come up, it is convenient to consult the application and working conditions of any of these products because of the high specialization of bellows engineering.
A pair of bellows is an element of just one piece that can expand. It is made from a metallic tube with specific wall measurements and thickness. The latter is turned into a corrugated unit by hydraulics or automatic means.
The basic tube is made from a metal sheet using one of the following methods:

a) Conventional method: it consists of a series of inlaying and stretching operations until a seamless tube is obtained.
b) Some bellows are made from welded tubes.

In both cases the tube wall thickness is approx. 0,005” but the range of thickness available extends below and above this number.
Most bellows are made by hydraulics means; others are laminated. In some cases, it is better to use a combination of both methods to guarantee the required characteristics.
Our company has the facilities to produce any of these bellows in small or big lots.

Laminated Bellows

The process consists of making up, from a stretched tube, a number of enlarged waives that then they will be deepened and narrowed with appropriate wheels.
The tube diameter used in this process is smaller than the outer diameter and bigger than the inner diameter of the finished bellows.
The outer and inner curving surfaces are cold-worked resulting in this type of bellows having excellent elastic characteristics.

Hydraulic Bellows

The tube is placed inside a mold inside which hydraulic pressure is applied. While it expands externally, penetrating in the fluting of the mold, it is at the same time folded lengthwise producing a completely corrugated bellows in just one step.
The external diameter of a hydraulic pair of bellows is approximately the same than the original tube (when a combination of the two processes is used, the inner diameter of the bellows is even less than that of the tube).
The hydraulic process allows the production of bellows that employ the base of the tube as the integral end, eliminating the joint operations as required to an end made with an independent part.

Multilayered Bellows

They are produced by laminating two or more tubes made in the same way as the simple-wall bellows. Multilayered bellows offer greater resistance to pressure without excessive effort on flexibility.

Corrugated

The bellows is made of a number of active corrugations plus another part of itself to which the end parts are fixed. The shaping of these parts and the method of tightening determines if part of a corrugation is inactive.
An active corrugation consists of two lateral walls connected to the curved part.
So as to avoid misunderstandings about the orders, determine the number of active corrugations and the type of end required.

Metals

Brass, phosphorous bronze, copper. For special services they can be made with other appropriate metals.