Cargo Tank Overpressure Measurement and Alarm System
Using pressure transmitters connected to a central control panel, the system detects over or under (vacuum) pressure conditions in a cargo tank, and triggers an alarm to prevent deformation and damage in case of primary pressure release valve failure.
A Cost Effective and Simple System for Product and Cargo Tankers
SOLAS II-2/59.1 regulation effective July 1998, and subsequent SOLAS II-2/4.5.3.2.2, II-2/11.6.3.2 and IACS UI SC 140 regulations effective July 2013, requires that a secondary means of allowing full flow of vapour, air or inert gas is provided in the event that the primary pressure relief valve arrangement fails. This ensures that the cargo tank is operated within its design limits and is not mechanically damaged by over or under (vacuum) pressure.
Alternatively, and more cost effectively (especially where retrofit is required), the regulation allows that pressure sensors may be fitted to each tank and their outputs routed to a monitoring system in the cargo control room which will provide an alarm in the event of a cargo tank over or under pressure condition.
The regulations are applicable to all vessels that transport flammable cargoes, or additionally fitted with an inert gas blanket system as part of the fire prevention system, these are typically crude oil, fuel and chemical cargo tankers.
PSM has produced a cost effective complete package based on proven and approved equipment which contains all that is needed to fully meet the above requirements:
The ict 1000 pressure transmitter is fully protected against positive or negative overloads and submersion. It is available with a choice of flanged or threaded fittings for installation directly to the tank top or piping into the venting system.
The MTU display unit located in the Cargo Control Room provides a monitoring station which provides an indication of normal or alarm status for each tank, as well as the actual pressure.
Key Features
- Detects over or under (vacuum) pressure conditions in a cargo tank and triggers an alarm to prevent deformation in case of primary pressure release valve failure.
- Complies with SOLAS II-2/59.1 regulations by providing an alternative to the secondary venting of cargo tanks.
- Also complies with subsequent SOLAS II-2/4.5.3.2.2, II-2/11.6.3.2 and IACS UI SC 140 amendments.
- Meets the ExxonMobil MESQAC guide for affiliate vessel vetting as well as OCIMF and SIRE best practices.
- Four alarm setpoints may be assigned for each tank over a range of –500 to + 500 mbar.
- The status of all tank measurement points is shown on a display with local visual and audible alarms. Additional relay outputs can provided for repeater alarms.
- The unit’s standard configuration will suit most applications, but changes to tank details, setpoints and acceptance delays are easily made.
- Cost effective to install in new builds or as a retrofit to existing ships.
- Simple to operate and reliable based on marine approved components.