Drain Valves

Marine drain valves are used in systems where controlled removal of water or liquid phase is required from piping, vessels, actuation loops, and individual sections of fire protection or auxiliary service networks. In naval applications, a drain valve is not assessed only as a discharge point, but as a functional element of the control sequence, particularly when associated with AFFF or magazine sprinkler systems.

One example in this category is the Cla-Val 100M-1KR, identified as a water drain valve for AFFF systems and manufactured in accordance with MIL-F1183. Cla-Val technical literature describes it as a remote control valve used in the hydraulic actuation section of a dry-type magazine sprinkler system. The 3/8 in. 100M-1KR operates as a normally open auxiliary control valve and closes when remote control pressure is applied.

The valve operates together with the hydraulically actuated check valve 81PM-1, X60 orifice flange assemblies, and pilot/manual control arrangements to shift the magazine sprinkler valve between the open-valve loop and the closed-valve loop. When control pressure is introduced, the 100M-1KR closes and permits the corresponding activation of the closed loop. When control pressure is vented, the valve returns to the open position and the system reverts to its normal standby condition.

Valve selection should verify service media, control pressure range, MIL-F1183 union connection requirements, elastomer compatibility with seawater or foam concentrate solution, pilot line cleanliness, and the ability to carry out functional testing without unintended flooding of the protected space. Maintenance should include inspection of the seat, diaphragm, restriction orifices, fittings, and deposits from salts or AFFF residue, since small obstructions can change response time and affect control sequence behavior.