Installation of flammable and toxic gas detectors
Thread Content
The PTA unit platform is a grid-type platform, and combustible and toxic gas alarms are installed at the bottom of the unit area; no such alarms are installed above the second floor platform. During the inspection by the experts at the company, it was suggested that combustible and toxic gas alarms should also be installed on the process equipment platforms; however, GB50493 does not provide any explicit guidelines regarding this. I’m asking fellow sailors: what standards should be referred to in this situation?
I use an alkylation process here as well, and steel grills are employed. The design does not include any combustible gas alarms; however, if the platform is covered with patterned plates, such alarms are necessary. It seems that GB50493 mentions the requirement to install combustible gas alarms along certain inspection routes, but since steel grills do not provide an environment in which combustible gases can accumulate, it should not be necessary to install such alarms
Thank you; these days some experts have distorted the process of conducting examinations – they draw conclusions without providing any basis for their findings.
This post was last edited by Hariky on 2018-2-10 at 12:00. The guidelines require the establishment of two basic principles. First, the leaking medium can reach 25% LEL ； Second, locations where it is easy to accumulate. In other words, if the medium contains flammable substances, but at a concentration far below the 25% lower explosive limit, it is not necessary to install such devices. Also, it is not necessary to install them in locations where accumulation is impossible; for example, steel grating in this case is not required for combustible media with high molecular weights. Additionally: Combustible/toxic gas detectors are intended to alert personnel to take safety precautions, rather than to detect leaks ； No, it’s not necessary to set it up just in case of a leak. Just as it is not necessary to install them in places where flammable/toxic gases are likely to be present throughout the year. Those who enter this area must take protective measures. Experts who say that testing points should be placed on the grating are nothing but so-called experts who are trying to deceive people.
The three-tier platform of my air compressor unit is also made of steel grating, but flammable and toxic gas detectors have been installed on it
The density of flammable and toxic gases also needs to be taken into consideration; in the event of a leak, will they accumulate in lower areas or evaporate and gather in higher areas?
Gas combustible gas detectors with a density lower than that of air are generally installed above.