Patent Application
20190137010
Piping is often run atop and across flat and low-slope roofs to serve HVAC and refrigeration devices. These pipes may be used to supply gas or water, or to drain condensate or evaporative “bleed” or “purge” water to drains. Steel, copper, and polymeric piping are commonly used in these applications. These pipes are supported above the roof surface to provide clearance beneath them for rainwater and debris. Historically the pipes have rested on wooden support blocks to which they are secured with metal pipe clamps. Depending on system weight, they may or may not be secured to the roof surface with a mastic or, on “single-ply” polymeric roof sheets, with a wrapping membrane that is compatible with the roof membrane. Over time these wood-based support blocks dry and age such that they need replacement. Also, the plastic-wrapped variants are quite costly.
More recently, new, more permanent support block designs have emerged that do not use wood. Examples are seen in U.S. Pat. Nos. 6,364,256, 6,682,025, 7,735,270, 8,356,778, and 8,540,194. The Olle patent (U.S. Pat. No. 7,735,270) shows a design now in use that uses a heavy, solid rubber block with a slot in which a strut-type clamp system inserts, while the Miro patent (U.S. Pat. No. 6,364,256) shows a complex design that has not been commercialized. The Birli patent (U.S. Pat. No. 8,356,778) is the most interesting of these, in its combination of two extruded shapes to provide flexibility as to pipe size and mounting height. The Turner patent (U.S. Pat. No. 6,682,025) discloses a one-piece extrusion that is not adjustable for pipe size. This design includes in its profile a “partial circle” recess that clips securely onto the pipe, with the mounted pipe extending along the direction of extrusion of the one-piece support. This design is likely the least-costly in the prior art, but it does not allow a single extrusion to be used for multiple pipe sizes, nor does it allow pipes to slide for expansion and contraction when the support is secured to the roof. The Azuma patent (U.S. Pat. No. 8,540,194) uses a hollow plastic extrusion with slots into which strut-type pipe clamps may be secured.
This invention responds to the short life of traditional rooftop pipe supports, the high cost of other newer, longer-life designs, and the need for long straight runs where the supports are adhered to the roof and the supported pipes can move freely in their supports under the forces of thermal expansion and contraction.
The polymeric extruded shapes presented here, with pipe support holes and open-top cuts transverse to the extrusion direction, provide excellent long-term pipe support, with free movement of the supported pipes, at lower initial and installation costs compared to the prior art.
Rooftop pipe support cost becomes a significant issue in the context of rising metal costs, which are causing a shift to polymeric pipes in appropriate applications. Copper water supply and drainage pipes are increasingly subject to theft and thus are being replaced by wrapped, painted, or UV-resistant PVC pipes, but due to its lower strength, PVC requires more closely-spaced supports, which increases support system cost. Also, polymeric pipes experience much more thermal expansion and contraction than metal pipes, thus requiring more attention with the support system to accommodate pipe movement. This invention provides simple, one-piece, UV-resistant pipe supports that:
1. Significantly reduce installed costs
2. Allow pipes to slide in the support as they expand and contract
3. Install quickly and easily without tools
4. Do not need metallic or other specialty parts to clamp pipes to supports
5. Can easily be secured to roof surfaces with mastic/adhesive
6. Can be removed without harming the roof surface
7. Withstand the rigors of weather for the piping or roof surface lifetime.
Much like the “breakout” shown in
A significant advantage of these designs is the speed of field placement. It is not necessary to place and tighten clamps as with most other rooftop pipe support designs and products. Securing to the rooftop with mastic or adhesive facilitates straight-line retention of long pipes without endangering the roof surface, since the pipes can move freely in the support blocks. This is a particular advantage when used on roofs with single-ply membranes.
The dimensions of the support extrusions and support holes described here may vary as to width, height, and length depending on pipe sizes and weights supported. Wall thickness of the extruded shapes may also vary with loading conditions. Multiple pipes may be held in a single support, typically with the support's length extended in the extrusion direction.
Although the invention has been described with reference to various exemplary embodiments and their combinations of features, the invention extends to the other possible combinations of the described features, as summarized in the claims that follow.
