The support of pipe risers subject to thermal expansion or contraction has presented tremendous problems for mechanical and structural engineers, and Mason Industries was there to help.
Our long standing, and proven recommendation of supporting a solid, straight riser on springs, is still the best solution. This method utilizes a central isolated anchor which cuts the maximum growth or contraction at the ends of the pipe in half, and becomes a neutral point during operation. Springs are selected and strategically placed above and below the anchor point, to provide continuous support and limit load changes as the pipe elongates and contracts. Since there is no discontinuity in the line, the pipe wall handles the thrust load eliminating the need for huge anchors and guides that are required with expansion joints.
We have successfully designed thousands of spring supported risers in our 55 years, but we realize that one size does not fit all, and there are situations where inserting a riser expansion joint, is the best option. As with the spring system, we are not just supplying hardware, but help with the complete design. This includes calculated riser loads and movements at all floors and branch lines which is vital information for the structural engineer. In addition to this fundamental data, we can also help design the riser brackets that have to be strong enough to transmit loads to the supports, anchors and guides. On some projects, seismic loads must be considered too. Should you like us to assist the construction team with the design of the shaft support steel, it would be our pleasure.
The following photographs and drawings are from a recent expansion joint project, The Albert Sherman Center at the University of Massachusetts. This 6″ Hot water supply and return pipe riser incorporated our HEJFFL expansion joint, ADA anchors, and VSG guides, as shown in the design drawings.
We are pleased to have been invited to work on risers for both World Trade Center towers 1 and 4, the tallest buildings currently under construction. Our products and designs are installed in the great majority of the world’s tallest buildings.
Please call us should you need help with your riser designs.
The Mason spring system is described in more detail in Bulletin RISER-112, which includes our recommended riser support specification.
Figure 1 Mason HEJFFL Housed Expansion Joints (Shown with Control Rods for Pressure Test to reduce Anchor Loads)
Figure 2 Mason ADA Rubber Cushioned All-Directional Anchors
Figure 3 Mason VSG Rubber Cushioned Vertical Sliding Guides