What is different Drainages Type of Close & Open

What is different Drainages Type of Close and Open The drain system design is based on segregated systems

The drain system design is based on segregated systems, described as following below.

 

The Open Non-Hazardous Drainage System provide drainage for locations that are designated non-hazardous. This system is segregated from all other open or closed drain systems.
Non-hazardous areas generally include storage vessel areas for utility materials such as lubricating oil, diesel fuel, etc. The drain system from these areas, referred to as the Open Non-Hazardous Drains (ONHD), handles fluids collected from open drip pans, tundishes and floors in non-hazardous areas.

Discharge of the ONHD to the system shall be by open galleys for the floor drains and a tundish type system for equipment maintenance drains. The disposal stream is discharged into the API Separator 1 Skimmer. The hydrocarbons settling out in the Separator / Skimmer will be pumped to burn pit for final disposal.

The Open Hazardous Drainage System provides drainage for areas that are designated hazardous. These generally include all process areas and locations where hydrocarbons are present in significant quantities. The drains system from these areas, referred to as the Open Hazardous Drains (OHD), handles fluids collected from open drip pans, tundishes and floors in hazardous areas. The open drain system must only be used for draining hydrocarbon fluids from process vessels after preparation for maintenance (depressurization).

The OHD streams are collected and routed to the API Separator Skimmer by a separate channel. Collected hydrocarbons are pumped to burn pit for final disposal.
Water from open drain system will be directed to the API separator / skimmer and then disposed to the river. The design of the water handling system as minimum it will comprise:

- API Separator / Skimmer
- 1 x oily water pump

The Closed Drain System (CD) consists of a permanent pipe work connection and collection header for routing drained liquids to a vented closed drain drum. It handles hazardous fluids from process vessels, keeping them out of contact with the atmosphere.
The Closed Drain Drum is designed with sufficient volume to receive the drained fluids and to permit vapor disengagement. A safety margin is applied to cover additional volumes, which may be drained. A high level alarm is installed to prevent overfilling. The drum shall have a minimum design pressure of 100 psig (eliminating the risk of rupture in the event of a deflagration). The vent is sized to discharge the highest vapor flow that could enter the drum if gas blow by should occur.

The sizing requirement for the closed drain drum pumps is the removal of all liquids between LLH and LLL in 30 minutes to the API Separator/Skimmer. Overview of drain system:

Reading and watching video while drinking coffee

• [accordion]
• 1. Liquid Drainage (Open & Closed Drain System)
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• 2. Vents and Drains in Piping System
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• 3. Physical Properties of Hydrocarbons Vol 1 by Robert