This specification provides the minimum requirements for design, construction, performance, and testing of devices to prevent marine tank liquid overpressurization (hereafter called spill valves). Materials of construction shall be suitable for the service intended and resistant to the attack by the liquid carried in the tank being protected. Corrosion test, hydrostatic test, performance test, freeze test, vapor tightness test, seaworthiness test, and production test shall be performed to conform with the specified requirements.

1.1 This specification provides the minimum requirements for design, construction, performance, and testing of devices to prevent marine tank liquid overpressurization (hereafter called spill valves).

1.2 The spill valves provided in accordance with this specification will satisfy Regulation 1I-2/59.1.6 of the 1981 and 1983 Amendments to the International Convention for the Safety of Life at Sea, 1974 (SOLAS), which states: “Provision shall be made to guard against liquid rising in the venting system to a height which would exceed the design head of the cargo tank. This shall be accomplished by high level alarms or overflow control systems or other equivalent means, together with gaging devices and cargo tank filling procedures.''

1.3 The spill valves are not intended for the venting of vapors or the relief of vapor overpressurization or underpressurization of marine tanks.

1.4 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.

1.5 The following precautionary caveat pertains only to the test methods portion, Section 8, of this specification: This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.