Multi Arch Rubber Bellow
Product Info
Multi arch Flexible Rubber Expansion Joints are designed to absorb movements and stress on piping systems, Double Sphere Flexible Rubber Expansion Joints’ connecting distance is relatively large.Compared with the Single Sphere Flexible Rubber Expansion Joints,the maximum pressure which He can withstand is smaller than Single Sphere Joint. But, in the middle part of the rubber joint is pressurized ring. Each layer is impregnated with a rubber or synthetic compound. This allows movement and flexibility between the layers of fabric.Double Sphere Flexible Rubber Expansion Joints is easy to install and maintain because of the small volume and flexibility.The inner seamless high-pressure rubber joint is developed by our own which prevents corrosive medium from etching the inner wall of the rubber joint in high temperature, acid, alkali and oil resistant pipeline. We can assure the quality and if you put up some other specific requirement, we will take them into consideration and fabricate as per that.
RUBBER BELLOWS
A rubber bellow is manufactured from independent rubber layers and reinforcements that are vulcanized together after being molded or formed. With over 35 rubber elastomers available and the ability to further modify properties by compounding it can be challenging for non-specialists to select the most appropriate rubber polymer for their requirements. Our experts may assist our customers with material selection for a proper performance and to reduce the risk of failure.FABRIC REINFORCEMENTS
Standard constructions normally utilize high quality synthetic fabric like Nylon, Polyester. Fabric plies are impregnated with rubber or synthetic compounds to permit flexibility between the fabric plies.METAL REINFORCEMENTS
Wire or solid steel strings are imbedded in the carcass and are used as strengthening members of the joint.FLANGES
Mild steel as standard. Also available in zinc plated or hot dip galvanized carbon steel, stainless steel, duplex, etc. Flanges drilled to EN, ANSI, JIS, AWWA standards or any specific dimension.TIE RODS
Rubber expansion joints under pressure (operating or test conditions) develop an axial reaction force across the effective bellows cross section area which acts on adjacent plain and fixed bearings. This bearing stress in the pipe system is drastically reduced by using lateral and/or angular expansion joints with tie rods. Only the adjustment forces and moments from the lateral or angular movement are introduced into the pipe system and absorbed by lightweight fixed points.TENSION RODS
This type of tensioning is used for lateral expansion joints or can be used to limit the element length on universal expansion joints. Threaded rods are placed symmetrically around the circumference and supported either with rubber bushes or with spherical washers, conical washers and nuts. Using rubber bushes creates a noise absorbing connection to the flange; this is done up to a Nominal diameter of maximum DN 300. For absorbing excess pressure (internal pressure), only external tensioning is required and additional internal tensioning for negative pressure (vacuum). All metal components such as threaded rod, nut, spherical washer and conical washer are galvanised as a standard. Versions mode from corrosion resistant materials or with hot galvanising are available on customers request.VACCUM SUPPORT RINGS
Rubber bellows resist small to medium levels of negative pressure, depending on Nominal diameter, design and application. For higher levels of negative pressure or full vacuum it is usually necessary to install vacuum support rings. These support the inner surface of the bellows curve and are made of stainless steel as a standard. Different designs are available, from a single open support ring and support rings with lock to a ring which is vulcanised into the bellows during production. The latter design is only available for type 2 rubber expansion joints. As a rule, the permitted movement absorption is reduced by approx. 50 % Precise data for vacuum stability can be found in the tables or supplied on request.FLEXIBLE BELLOWS AND HOW THEY WORK
Rubber Flexible bellows, also known as rubber bellow joints, are convulation that absorb movements in the pipe system. These movements they absorb are defined by axial, lateral, angular and universal movements. The flexible bellows can be designed to absorb one of these movements or to absorb more of these movements in combination.
Axial movement
Axial movement is movement of the rubber bellows in the direction of the longitudinal axis. This movement can be compressive, where the bellows shortens in length, or extensive where the bellows extends in length. In the majority of applications, the flexible bellows is deemed necessary because of the increasing temperature of the pipe system. The expansion joint is fitted in pipe systems and installed between two fix points (anchors). The extension of the pipe is compensated by the compression of the bellows. In some cases, typically cryogenic and chilled water services, the pipe system contracts in service causing the expansion joint to extend in length. Thermal expansion of the pipe system results in an axial compression of the installed expansion joints. The specifications for flexible bellows should always state the movements as they affect the flexible bellows, and not those generated by the pipe system.
Lateral movement
Lateral movement is movement perpendicular to the bellow’s longitudinal axis; it is a shearing movement of the bellows with one end offset from the other, usually with the ends of the bellows remaining parallel to each other. A single conversation bellow working with a shearing action, can accept a relatively limited amount of lateral movement, especially when the flow characteristics of the system demand that an inner sleeve is necessary. For larger lateral movement capability, it is usual to utilise a twin bellows arrangement with an intermediate pipe between the bellows. The flexible bellows lateral movement is taken up by an angular rotation of the bellows in opposite directions. The amount of lateral movement available depends on the rotational movement capacity of each bellows and the distance between them. Increasing the distance between the bellows increases the lateral movement capability of the flexible bellows proportionally. Lateral movement can be applied in more than one plane; in such cases it is important that the expansion joint designer is made aware of the total lateral movement to be applied.
