SSABS4 – 4” ABS Special support stands for installing pipes on uneven tank floors. SSABS4 – 4” ABS Support Stand – SSI Aeration. In SSI Aeration piping systems, support stands fulfill the dual role of anchoring pipes to the floor and controlling thermal expansion and contraction. Special support stands are available for: Uneven tank floors Installing into concrete ballast forms For tanks with significant channel velocity (with lateral supports Quality is rigorously monitored at SSI Aeration. So closely that you could call it our obsession. That means that every item we manufacture is designed to be the best in its category. When maintaining the integrity of wastewater treatment facilities around the world, having a system you can depend on is critically important. Whether it is our products, systems, or accessories, genuine SSI Aeration is the industry standard for quality control.