What device diverts the product water to the drain if the TDS alarm limit is exceeded on the RO?

The correct response highlights the function of a product divert valve in the reverse osmosis (RO) system. When the Total Dissolved Solids (TDS) levels exceed a predetermined threshold, it signals that the quality of water generated by the RO system is not acceptable for use. To protect downstream equipment and ensure safety, the product divert mechanism activates, redirecting the water away from the output line and to the drain instead.

In RO systems, maintaining water quality is critical. The product divert ensures that only water meeting the quality standards — specifically with TDS within acceptable limits — is allowed for further use or storage. This process prevents compromised water that could potentially damage components or negatively affect processes that utilize treated water.

Other devices mentioned, such as sample pumps, filtration units, or deionization units, serve different roles in water treatment processes. A sample pump is mainly used to take water samples for testing, while filtration units are designed to remove particulates from the feed water before it enters the RO system. A deionization unit is typically used for additional treatment after RO to further purify water but does not directly monitor TDS levels or handle product diversion based on TDS alarms. Thus, the product divert is the specific feature designed to respond to