General Description

IMO MSC/Circ. 677/1009, MSC.1/Circ. 1324
ISO 15364, ISO 16852
NON-HAMMERING / NON-OSCILLATING

N.D 65 ~ 300
JIS, ANSI, DIN etc FLANGE
WEIGHT LOADED TYPE

SEWON High velocity pressure vacuum valve provides automatic control of pressure differentials during cargo loading/unloading, ballasting, or thermal variations and gas freeing purpose on tanks. SEWON valve is designed to prevent the passage of flame into cargo tanks only if vent outlets on ships fitted with inert gas systems.

Operation

Before loading or unloading, the High velocity pressure/vacuum valve must be test lifted to assure the movable pressure, vacuum disc. The check lift is designed to be self-closing. 

Loading
When loading, the pressure unit of the SEWON High velocity pressure/ vacuum valve is in operation, Consequently, it must be check lifted by turning the check lift handle from its vertical position to the upper position and automatically back again, before the loading is commenced.

Unloading
When unloading, the vacuum unit may enter operation.
Consequently, it must be check lifted by pushing the vacuum check lift under the vacuum unit and automatically back again to the initial position. 

During the sailing, the SEWON High velocity pressure/vacuum valve will operate automatically and relieve pressure or vacuum caused by thermal variations. The large increase in effective pressure area which occurring when the valve disc is lifted up from its seat at first stage ensures nearly instantaneous full opening capability.

Options

 

Ice Class type

 

FOR ICING CONDITION
TEMPERATURE RANGE : -40°C
HEATING METHOD : STEAM OR ELECTRIC TRACING
SIZE : ND 65 ~ 300