DIN Flanged Overboard Valve Ductile Iron

Key Features

• Ductile Iron Body: Provides mechanical strength and toughness for marine piping applications. The specified material grade, corrosion protection and internal components should be matched to the service conditions.
• External Spring-Loaded Construction: The exposed spring assembly applies a closing load to the valve mechanism. Its setting influences opening behaviour and should be selected according to the required discharge conditions.
• Discharge Backpressure Support: A correctly selected spring-loaded arrangement can help maintain upstream backpressure during discharge. The required setting should account for flow rate, downstream pressure and the elevation of the discharge outlet.
• Local Handwheel Operation: Provides a means of operating the valve at the installation point without an external power supply. The handwheel’s relationship to the spring mechanism and any manual closing function should follow the operating instructions.
• Bolted Bonnet Assembly: Provides access to internal components for inspection and servicing after the system has been safely isolated, depressurized and drained.
• DIN Flanged Connections: Allow connection to compatible shipboard piping and facilitate removal during maintenance. Flange drilling, sealing faces and face-to-face dimensions should be checked against the installation drawing.
• Accessible Spring and Guide Assembly: The external arrangement allows visual inspection of the spring, support columns and associated fasteners. Sufficient clearance should be provided for operation and maintenance.

Applications

• Marine Overboard Discharge: Intended for consideration in shipboard water discharge lines where the valve’s construction, opening characteristics and operating limits meet the system requirements.
• Cooling Water Discharge: An option for compatible seawater or freshwater cooling-system outlets requiring spring-loaded discharge control.
• Shipboard Drainage Systems: May be considered for suitable drainage duties after reviewing fluid cleanliness, solids content, required flow capacity and the internal valve configuration.
• Auxiliary Water Systems: Applicable to compatible marine utility-water discharge arrangements where local operation and service access are required.
• Ship Repair and Dry-Dock Replacement: Suitable for consideration when replacing existing overboard valves, provided the connection dimensions, installation space, spring setting and required valve function are confirmed.

Valve Function and Selection

Spring-loaded overboard valves may use different internal arrangements. A stop configuration and a screw-down non-return configuration perform different functions; reverse-flow prevention should only be specified when the supplied disc arrangement provides it.

Before ordering, confirm the fluid, flow rate, operating pressure and temperature, required opening differential pressure, downstream backpressure, installation orientation and discharge location relative to the waterline. Flange pressure designation and spring opening setting are separate specifications.

Provide JS Flow with the required valve function, material specification and installation dimensions. Any inspection, pressure-testing or classification documentation requirements should be agreed before production.