Double Wall Tube Bundle Drawing 125 x

From the leader in Double-Wall Tubing

Our Double-Wall tubing meets Uniform Plumbing Code requirements for heating potable water.

Proven to prevent cross-contamination, it has been tested and certified by the City of Los Angeles Testing Laboratory.

  • Easy Inspections and low maintenance
  • Fully visible, 360º vented leak detection between tubesheets.
  • Bolting and gaskets for potable water and heating medium are completely independent.
  • Individual tube access for easy maintenance.
  • Optional: Tubesheet contacting potable water is solid 304 stainless steel.
  • Used to upgrade present single-wall tube bundles.
  • Available in storage semi-instantaneous water heaters and exchangers with copper or cupro-nickel tubes and carbon steel or stainless steel tube sheets (Up to 400 PSIG with cupro-nickel tubes)

Double-Wall Protection Performance

Tube failure can be caused by corrosion, erosion, and vibration, and can result in the contamination of the domestic water system to be contaminated by a heating medium such as steam, hydronic water, glycol solution, etc. There is no practical way to have the heating medium sterile or free from harmful treatment compounds or corrosion by-products. A low pressure heating medium circuit does not ensure contamination protection of indirect, single-wall water heaters. Whether they are shell and tube, shell and coil, plate and frame, or any other type, all consist of relatively thin wall heat transfer surface separating the heating medium from the domestic water system. Therefore, the potential for cross contamination is real and in some instances contamination has occurred. Several states and cities are now insisting on double-wall vented construction in all direct type domestic water heaters. Plumbing codes have also been re-written to include double-wall protection. Ace Heaters has developed the most practical, “state-of-the-art” double tube wall heaters to preclude any possibility of contaminating the domestic water system.

The Ace Series double-wall is the most positive form of double tube wall construction available, with no sacrifice in water heater efficiency or performance over a single tube wall heater.

The heat transfer surface is 5/8″ O.D. x .042″ thick inner wall and 3/4″ O.D. x .042″ outer wall SB-75 copper tubing. The .042″ dimensions are actual net tube wall thicknesses which equal .084″ thickness of total wall separation. This is more than twice the thickness of many single wall water heater products. Both inside and outside tube surfaces are smooth (prime) with no fins or surface irregularities to promote scale formation or corrosion attack.

Double-wall tubing has a similar overall heat conductivity as a single wall tube of equivalent wall thickness. Each tube has multiple parallel and continuous vent paths.