Under what conditions must welded handholes be used for safety?

Welded handholes are a critical safety feature in pressure vessels and piping systems, particularly when it comes to managing high-pressure environments. The correct condition for requiring welded handholes is at pressures exceeding 8370 kPa.

When pressure within a vessel approaches or exceeds this threshold, the risk of structural failure increases significantly. In such scenarios, welded handholes provide a more robust and secure means of access compared to bolted or flange-type openings, which might not withstand the mechanical stress at elevated pressures. Welded joints ensure that there is a continuous metal connection, significantly reducing potential leakage points and enhancing the overall integrity of the vessel.

In contrast, conditions such as high temperatures (like 454°C) or temperatures below 150°C do not specifically dictate the necessity for welded handholes in the same manner as pressure does. Similarly, pressures below 5000 kPa do not typically necessitate the added safety of welded handholes, as the risks associated with structural failure are not as pronounced, allowing for the use of different fastening methods. Therefore, the emphasis on pressure, particularly at levels above 8370 kPa, illustrates the need for welded handholes to ensure safety and structural integrity in high-pressure systems.