Whilst designing systems for process plants it’s often process control which attracts the attention of design engineers. However personnel protection for worker safety should gain equal priority. In the petrochemical and energy generation sectors, personnel protection standards are put in place by companies to protect workers operating in and around high temperature surfaces including pipelines, valves and vessels. These can often operate at high temperatures and steps should be taken to ensure that personnel are suitably protected.
We have summarised the top 5 things we think you should know about Personnel Protection
What are they? Personnel Protection is required under duty of care legislation to prevent workers from accidental burns as a result of touching a hot surface. There is no fixed standard for this, only company specific guidance. For example ASTM C1055 guidance recommends 140F or 60oC (*see ASTM source below). This has been shown to be the temperature an average person can withstand for 5 seconds before resulting in an irreversible burn.
What factors could unexpectedly affect surface temperatures. Errors in design calculations could be one, but more likely it’s pipe thicknesses (or changing thicknesses as a result of corrosion), jacketing, changing process temperatures from the initial brief and ambient temperatures
Why are they required and when are they needed? In simple terms safety is paramount and any avoidable risk of injury should be accounted for. More specifically speaking, personnel protection should be used where hot surfaces occur where work is likely or regularly to be carried out. Hot surfaces as we’ve said would be over 60oC but should be considered on a case by case basis, and apply mostly at heights under 2m from floor level (but again, this should be considered case-by-case).
How do you meet these recommended temperatures? Whilst ASTM has recommended a temperature of 60oC many engineers will specific 50oC to err on the side of caution. To achieve these many will use either insulating jackets or personnel protection such as that produced by Insulcon Technical. The benefits of Personnel Protection over jackets include Prevention of Corrosion Under Insulation and Ease of Inspection. These systems can be designed on a bespoke basis to allow for complex structures / shapes and varying temperatures.
Who enforces safe surface temperatures? In simple terms, they’re unregulated but companies will have procedures in place to ensure their own internal standards are adhered to. The guidance offered by ASTM in America is just that, guidance. This is largely because a “safe surface temperature” is entirely dependent on its environment. It is up to plant operators and owners to establish what they deem to be a safe operating temperature. Maximum outside surface temperatures are often spelled out in design specifications while some operators may prioritise their budget over personnel protection this clearly isn’t recommended guidance.
*ASTM Source