Question 377General Subjects - Assistant Engineer70% to pass
When renewing spiral packing in a centrifugal pump stuffing box, after the packing is firmly seated, the packing gland nuts should be _______________.
AI Explanation
The correct answer is A) loosened, and then retightened with the pump running under normal conditions.
When renewing spiral packing in a centrifugal pump stuffing box, it is important to ensure the packing is properly seated and compressed to prevent leaks. After the new packing is firmly seated, the packing gland nuts should be loosened slightly and then retightened while the pump is running under normal operating conditions. This allows the packing to adjust and conform to the shaft, creating a proper seal without over-compressing the packing, which can lead to increased friction and heat buildup.
The other options are incorrect because: B) fully loosening the gland until it clears the stuffing box would remove the compression on the packing, C) leaving the gland in the tightened position after seating the packing may result in over-compression, and D) tightening the gland an additional 10% could over-compress the packing.
Related Questions
#375 A centrifugal pump gradually develops insufficient discharge pressure. What corrective action is required? #376 A pump shaft that is bent or distorted should normally be _______________.#378 The capacity of a gear type rotary pump, when operated at a constant speed, will decrease with an increase in the pump _______________.#379 Why is the discharge pressure of a herringbone gear pump steadier than the discharge pressure of a simple spur gear pump? #380 How does the viscosity of a fluid being pumped affect the operation of a spur gear pump?