The Logic Behind The Magic."Open Drain System"

The Open Drain System is intended to collect and process atmospheric pressure drains from equipment or from deck drainage prior discharge to the environtment. This includes any liquids such as process drain, spill, and overflows.

There are two sub system to the open drain system. one is received drains from hazardoud area and the other receives drains from non hazardous areas. Drains from both systems are routed to the open drain tank which is overflow weir type separator. The overflow water will flow to the open drain caisson while the oil will flow to the internal oil compartment within the tank. The recovered oil will be pumped to the LP flare KO drum via open drain pump.

 The pump operates on- off based on level in the oil compartment. The pump will automatically start and stop when high or low oil level is reached under automatic remote mode.

The open drain caisson receives overflow water from the open drain tank to recover any oil from  the overflow meter. The caisson is equipped with an internal oil compartment with holes to allow oil overflowing into the compartment. The oil level is monitored through the level transmitter and operator is required to manually start and stop the portable caisson pump on initiation of high and low oil level.

Control loop Description
Level Transmitter
Level control in the open drain tank is performed by LIC by starting and stopping pump between the LAH and LAL levels. The pump is started / stopped by energizing solenoid valve on the utility air line, a selector swith in system is provided to select the pump operation mode either automatic or manual mode.