Distributed control system (DCS) are dedicated systems used for controlling manufacturing processes that are continuous or batchoriented, such as oil refining, petrochemicals, central station power generation, pharmaceuticals, food & beverage manufacturing, cement production, steel making, and paper making. Apart from DCS, servers and control rooms have more critical equipment for BPOS, IT/ ITEs etc. The presence of corrosive gases present in the facilities mentioned above causes micro – corrosion. Electronic Corrosion if left untreated for long is responsible for electronic malfunction, retarded performance and under extreme circumstances even electronic equipment failure thereby leading to server failure and downtime losses
While measures are in place for controlling temperature and humidity, gaseous contamination is generally overlooked. In addition to temperature and humidity, gaseous contamination should also be controlled.
How Electronic corrosion is caused ?
However, despite occasional human control, distributed control systems sometimes have problems. They are made up of various metals including copper and silver, something that may bring about copper corrosion and silver corrosion due to the chemicals being used and hence immediate corrective measures for electronic corrosion control is required.
Corrosion of metals is caused primarily by the attack of gaseous contaminants and is accelerated by heat and moisture. Higher than permissible amounts of gaseous contaminants like sulfur compounds present in the form of H2S, SO2, SO3. Nitrogen compounds present in the from NO, NO2, NO3 and Cl2 and Ammonia cause the electronic corrosion process. These react with the metal on ICs, and other electronic and electrical parts and form a non conducting layer which resists current flow leading to failures. The severity of damage depends on the kind of gaseous contaminant. Studies which have shown that atmospheres which cause corrosion above acceptable limits is as mentioned at right. Other problems that may be experienced include electronic corrosion leading to server failure, electronic failure, premature failure, etc.
ISA Environment Classes, Relative Humidity Less < 50%
| ISA Class G1 | ISA Class G2 | ISA Class G3 | ISA Class GX | |
|---|---|---|---|---|
| Copper Coupon film thickness (angstroms) | 0-299 | 300-999 | 1000-1999 | > 2000 |
| Gas Concentrations (ppb. by volume) | ||||
| ISA Class G1 | ISA Class G2 | ISA Class G3 | ISA Class GX | |
| H2S | < 3 | < 10 | < 50 | < 50 |
| SO2, SO3 | < 10 | < 100 | < 300 | < 300 |
| Cl2 | < 1 | < 2 | < 10 | < 100 |
| NOX | < 50 | < 125 | < 1250 | < 1250 |
| HF | < 1 | < 2 | < 10 | < 10 |
| NH3 | < 500 | < 10000 | < 25000 | < 25000 |
| O3 | < 2 | < 25 | < 100 | < 100 |
Class definitions
G1: mild-an environment sufficiently well controlled that corrosion is not a factor in determining equipment reliability
G2: Moderate-an environment in which the effects of corrosion are measurable and may be a factor in determining equipment reliability.
G3: Harsh-an environment in which there is a high probability that corrosive attack will occur. These harsh levels should prompt further evaluation resulting in environmental controls or specially designed and packaged equipment.
GX: severe ambient-electronic/ electrical equipment is not expected to survive in these conditions.
Prevent Electronic corrosion through Bry-Air
Process Industries and or IT industries having critical equipments in DCS rooms and or Server / Datacom rooms can prevent downtime caused due to electronic corrosion/ breakdown by installing a Bry-Air EcoScrub Gas Phase Filtration System. Bry-Air’s Gas Phase Filtration System removes corrosive gases by a process of Adsorption and Chemisorption using the BrySorb impregnated media. The Bry-Air EcoScrub is designed to maintain various electronic environmental standards such as ISA standard 71.04, IEC standard, Environmental standards followed by electronic manufacturers all over the world for smooth operation of electronics. Bry-Air’s Airgineers have nearly 50 years of experience and have installations in every nook and corner of the world.
