As MAC-W but incorporating control units/tie rod system. A control unit assembly is a system of 2 or more control rods placed across the expansion joint from flange to flange to set the maximum allowable expansion/contraction of the expansion joint and that will contain the pressure thrust. Recommended on most applications to prevent damage due to excessive pipe movements, each rod incorporates double nuts on each end to keep the expansion joint from over- elongating and spherical washers to allow Lateral, Angular and some Torsional movements as well as to accommodate moderate piping misalignments.
Standard Moulded Rubber Expansion Joints - MAC-WT | Macoga
MACOGA MAC-WT – Standard Molded Elastomeric Expansion Joint with Tie Rods
The MAC-WT is a standardized, single-arch molded elastomeric expansion joint equipped with loose flanges and a control unit/tie rod system. It is specified for piping systems requiring vibration absorption, axial, lateral, and angular movement accommodation, and restriction of elongation due to pressure thrust.
Construction and Operating Limits
- Standard range: DN25 to DN600
- Larger sizes: custom up to DN6000
- Operating pressure: 16 bar up to DN300, 10 bar for DN350–DN600
- Typical movements: compression 30 mm, elongation 20 mm, lateral 20 mm
- Angular movement: from 35° (small diameters) to 6° at DN600
- Vacuum service requires internal vacuum ring
Tie Rods and Comparison with MAC-W
The MAC-W is unrestrained and transmits axial pressure force to pipe anchors. The MAC-WT incorporates two or more tie rods between flanges to define maximum elongation/compression and restrain pressure thrust. Double nuts limit over-extension, while spherical washers allow lateral, angular, and limited torsional movement.
Materials and Media Compatibility
Available elastomers: EPDM, EPDM HT, NBR, white NBR, Hypalon/CSM, SBR, Neoprene, FKM/Viton. EPDM is used for water, hot water, saline solutions, and oil-free air. NBR is selected for oils, fuels, and hydrocarbons. SBR is suitable for wastewater, sludge, and solids-laden media. FKM/Viton is specified for chemicals, solvents, and hydrocarbons up to 150°C.
Installation and Sealing
No additional gasket is installed between the elastomeric face and pipe flange. Bolting is cross-tightened in stages using a torque wrench. For beaded-end MAC-W series, indicative torques range from 40–60 Nm (DN25–50) to 110–175 Nm (DN600).
Applications
Pump stations, HVAC, chilled/hot water, cooling water, desalination, oil & gas auxiliary lines, chemical plants, shipbuilding, water treatment, and sewage. No actuator is involved; selection is based on DN, pressure, temperature, media, required movements, vacuum, and available pipe anchoring.
Datasheet and documents
Description
CERTIFICATES
MACOGA holds numerous industry approvals, including:
Ministry of Defense and NATO Member Countries
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