Guard design overcomes corrosion snag
01 May 2008
Cable glands used in hazardous areas particularly in the offshore and onshore petrochemical industries are susceptible to corrosion either in the form of environmental or chemical attack.
Glands are traditionally manufactured from brass, which offers fairly good resistance to mild corrosive conditions. However in the petrochemical process industry, brass glands do not offer adequate protection against chemicals such as hydrogen sulphides, ammonia and nitric, hydrochloric and sulphuric acids. Glands in such environments can completely corrode away in months not years, which means that the corrosion takes place undetected before the next periodic inspection.
A corroded gland will at some point lose its function and hence no longer perform as a safe certified item. This leads to a potentially dangerous situation as the explosion proof seals relax and the earthing on armoured glands is compromised.
In the past shrouds have been used to protect the glands against this corrosive attack. Shrouds however are prone to degradation from heat cycling, UV and can be dislodged by physical forces and high winds and water spray such as that which is found on offshore oil installations. In addition shrouds have been known to trap moisture rather than keep moisture out with the result that corrosion of the gland sets in behind the shroud undetected.
The only alternative to brass in these kind of environments has been very expensive stainless steel glands (up to 10 times the cost of an equivalent brass gland). These glands have long delivery lead times to manufacture and manufacturers are reluctant to make them.
CCG's solution to the problem of corrosion of brass cable glands is the screw on Corrosion Guard. This is essentially a non-metallic rigid screw on shroud which screws onto the gland in the place of the gland back nut. It engages a sealing gasket at the base of the gland and has a seal which compresses over the outer sheath of the cable, totally encasing the metal gland thus giving IP 66/68 protection. The material is resistant to all aggressive chemicals and has a high impact and UV resistance.
In addition the Corrosion Guard can be unscrewed from the gland for inspection purposes without the need to unscrew the metal parts of the gland.
In short the benefits of the Corrosion Guard are long service life, ease of installation and inspection all at a lower cost.
The CCG Corrosion Guard was runner up in the HazardEx Awards’ Technical Innovation of the Year 2007.
CCG Cable Terminations
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