What is the required operating condition for a packing type pump seal during commissioning?

The required operating condition for a packing type pump seal during commissioning is that the packing must drip steadily. This is because, in a properly functioning packing seal, a small amount of leakage is necessary to provide lubrication and cooling for the packing material. This controlled leakage creates a hydrodynamic effect that helps to maintain the seal and reduces friction. It also ensures that the packing does not overheat or wear out prematurely, which could occur if it remained completely dry or under excessive pressure. The presence of a steady drip is an indication that the seal is functioning correctly and is not over-tightened, which could lead to increased wear and a higher risk of seal failure.

In contrast, other conditions like having the packing remain completely dry would lead to inadequate lubrication and result in quick wear or damage. Being fully submerged in oil isn’t typical for packing seals used in pumps, as these seals are designed to function with a certain amount of leakage rather than being inundated with oil. Lastly, a packing seal that does not leak at all would indicate that it is too tight, potentially causing overheating and premature failure. Thus, a steady drip signifies optimal performance for a packing type pump seal during commissioning.