Full Face Rubber Flanged Expansion Joints - MAC-FB In-line | Macoga

Name: Full Face Rubber Flanged Expansion Joints - MAC-FB In-line | Macoga
Brand: Macoga
SKU: Full Face Rubber Flanged Expansion Joints - MAC-FB In-line | Macoga

MACOGA MAC-FB In-Line – Pressure Balanced Full-Face Flanged Rubber Expansion Joint

MAC-FB In-Line is a pressure-balanced elastomeric expansion joint designed for straight-line installation in piping systems where pressure thrust must not be transmitted to pumps, turbines, heat exchangers, or equipment nozzles. It absorbs axial and lateral movements, while internal pressure loads are neutralized within the unit, minimizing load transfer to connected equipment.

Operating Principle

The assembly consists of a primary in-line elastomeric element and an additional pressure-balancing element, both exposed to the same process pressure. The opposing force generated by the balancing element reduces axial load transfer to the piping or connected equipment. This allows installation between intermediate fixed points without the need for main anchors to absorb pressure thrust.

Construction

Type: Pressure balanced, full-face rubber flanged.
Configuration: In-line, with single or multiple convolution sections.
Flanges: Metallic backing flanges, split or fixed.
Drilling: EN, ANSI, AWWA, JIS, or project-specific patterns.
Dimensions: Custom fabrication available, suitable for large diameters.
For vacuum service, internal vacuum rings are provided as required.

Materials and Media

Available in EPDM, EPDM HT, NBR, white NBR, CSM/Hypalon, SBR, Neoprene, Butyl, natural rubber, and FKM/Viton. EPDM is typically used for water, hot water, brine, and oil-free air. NBR is selected for oils, fuels, and hydrocarbons. FKM/Viton is suitable for chemicals, oils, and high-temperature solvents.

Difference from MAC-FB Elbow

In-Line is installed in straight pipe runs where compensation is required without a change in piping direction. Elbow is used in angular configurations where network geometry or equipment layout requires a directional change.

Standards and Use

Design follows FSA Non-Metallic Expansion Joints Technical Handbook, ASTM F1123-87, and PED 2014/68/EU for specified operating conditions. No actuator is required; selection is based on DN, pressure, temperature, media, movement, vacuum, and allowable loads in the system.

Datasheet and documents

Description

These expansion joints accommodate axial and lateral movements and counteract the bellows pressure thrust. They can be fabricated with single and multiple arches.

An additional bellows is incorporated into the unit and is subject to the line pressure to generate a force equal and opposite to that on the main bellows. Tying these bellows together neutralizes the pressure load on the unit.

The Pressure Balanced Expansion Joints are used in situations similar to those described for the Axial and/or Lateral Expansions, although this particular type of Expansion Joint offers the additional advantage of not transferring the thrust caused by the internal pressure to the pipes or adjacent equipment.

This characteristic is especially important when it comes to joining the pipes to turbines or other delicate equipment which, by their nature, are unable to withstand these extra loads. The only loads on the equipment are the sum of the forces required to move the line bellows and balancing bellows of the expansion joint.

This type of Joint can be fitted between intermediate fixed points so main anchoring of the pipe or adjacent equipment is not required.