Test & Drain Valves

Test and drain valves are essential components in fire sprinkler systems, designed to facilitate both routine inspection and system maintenance. Their primary function is to allow controlled discharge of water from a system, either to simulate sprinkler activation during testing or to remove water during repairs, modifications, or seasonal draining.

Traditionally, two separate devices were used: an Inspector’s Test Valve and a Drain Valve. The inspector’s test valve simulates the opening of a single sprinkler, enabling flow through the alarm device to confirm proper operation of waterflow alarms and system response. The drain valve, often called the main drain, allows for system drainage as well as system water to be released at full flow to check water supply availability and monitor for obstructions or pressure loss.

Modern manufacturers also provide combined test and drain valves, which integrate both functions into a single compact assembly. These combination valves incorporate multiple orifice sizes, a sight glass or port, pressure relief valve, and simplified operation, reducing installation time and the number of system penetrations required. Whether separate or combined, test and drain valves serve a vital role in ensuring fire sprinkler systems remain reliable, code-compliant, and easily maintainable throughout their service life.