Gate Valves

Marine gate valves are used as isolation devices in shipboard piping systems where full-bore opening with low pressure drop is required, and not continuous throttling of flow. Selection is based on the service medium, flange pressure class, corrosion potential, nominal diameter, available operating clearance, and the ability to inspect the stem, packing, bonnet, and seating surfaces.

This category includes JIS gate valves with flanged ends in 5K, 10K, and 16K pressure classes, with body materials including bronze, cast iron, and cast steel. Available designs cover JIS F7367 and F7368 in bronze, F7363, F7364, and F7369 in cast iron, and F7366 in cast steel.

Bronze gate valves are typically applied in smaller sizes and auxiliary water systems where compatibility with marine environments is required. For example, JIS F7367 is specified as a rising stem bronze 5K gate valve, with body, bonnet, and wedge in BC6, tested in accordance with JIS F7400-1996, with hydrostatic shell test pressure of 1.05 MPa and seat test pressure of 0.7 MPa.

Cast iron and cast steel versions are selected for larger diameters or lines subject to higher mechanical loading. JIS F7364 in class 10K is specified with FC200 body construction, BC6/SCS2 seating materials, and shell test pressure up to 2.1 MPa for sizes through DN400. JIS F7366 uses SC450 cast steel body material with test pressures of 2.1 MPa for the shell and 1.54 MPa for the seat.

For installations using European standards, a DIN F4 NRS metal-seated gate valve is available in accordance with DIN EN 1171 / DIN 3352 T2, with non-rising stem and open/close position indication. Typical services include cold water, hot water, fresh water, seawater, and lubricating oil. For sounding pipe applications, self-closing gate valve heads are available to JIS F3019, with shell test pressure of 0.3 MPa and seat test pressure of 0.2 MPa.