Advanced Mechanical Seal Quiz #1

When working to seal a fluid, it is important to use environmental controls that make the fluid clean, cool, and lubricious (film forming). This means that the fluid should be free from contaminants, maintained at a lower temperature to prevent overheating, and have a lubricating property that allows for smooth movement and reduces friction. These conditions help to ensure effective sealing and prevent any damage or wear to the sealing components.

The correct answer suggests that when dealing with a sticky fluid and a poor seal face lubricant, the best approach is to use a dual seal or High Velocity Seal (HVS) with a clean barrier fluid or lubricant. This barrier fluid should be pressurized to 1 bar higher than the sealed pressure. This arrangement helps to prevent leakage and maintain a proper seal in challenging conditions.

The best way to determine the best environmental control option is to estimate the costs and match them to the process needs. This means that one should consider the financial implications of each control option and assess how well it aligns with the specific requirements of the process. By estimating the costs and evaluating how well the options meet the process needs, one can make an informed decision on the most suitable environmental control option.

Liquid lubricated mechanical seals cannot run at high speed with no seal face lubrication because the seal faces need to be lubricated in order to reduce friction and prevent excessive heat generation. Without proper lubrication, the seal faces would wear out quickly and lead to seal failure. Therefore, it is important to provide adequate lubrication to ensure the smooth operation of the mechanical seal at high speeds.

The correct answer is 180H. This mechanical seal model is designed to be used in hot water up to 170 C/350 F without the need for cooling. The "H" in 180H likely stands for "high temperature" or "hot water," indicating that this specific model is specifically designed and capable of withstanding higher temperatures without the need for additional cooling mechanisms.

Chesterton's Rotary Equipment Sales Tool can be used to determine the actual PV (Pressure-Volume) based on the operating conditions. This means that the tool helps in calculating the pressure and volume of the fluid being sealed, taking into account the specific operating conditions such as temperature, pressure, and flow rate. By determining the actual PV, users can make more accurate decisions and select the appropriate equipment for their needs.

When the 180H is used in a service that starts at 150C and is then cooled to 20C, we would expect leakage at the cooler temperature. This is because the sudden change in temperature can cause the material of the 180H to contract, leading to potential leaks or cracks. The cooler temperature may cause the material to become more brittle and less able to withstand the pressure, resulting in leakage.

The statement is false because it is possible to demonstrate the financial value of one environmental control versus another. By conducting cost-benefit analyses and comparing the costs and benefits of different environmental controls, it is possible to determine their financial value. This can include evaluating the costs of implementation, maintenance, and potential savings or benefits in terms of energy efficiency, reduced pollution, or improved health outcomes.

A pumping ring seal (180PR/442PR) is typically considered in service above 350 F or 170 C because at temperatures below this range, the seal may not be able to withstand the high heat and may fail. Therefore, it is recommended to use this type of seal for applications where the temperature exceeds 350 F or 170 C to ensure its proper functioning and longevity.

DirectFit Seals are specifically designed to be compatible with certain pump manufacturer and models. In this case, the correct answer suggests that the Sulzer APP and APT pumps are suitable for using DirectFit Seals. It implies that these pumps have a compatible design and can easily accommodate the DirectFit Seals without any modifications or additional adjustments. Other pump manufacturers and models listed in the question may not be suitable for using DirectFit Seals.

The main difference between a 442 and 442M Split Seal is that the 442M Split Seal rotates the narrow face to avoid wiping, uses a machined gland, and allows motion. This means that the 442M Split Seal is designed to prevent wiping and damage to the seal face, while also allowing for movement and flexibility. In contrast, the 442 Split Seal may not have these features and may not be able to rotate the narrow face or allow for motion.

The statement suggests that 180H hydro pad seals can work well in a light slurry, but the correct answer is False. This means that 180H hydro pad seals do not perform well in a light slurry.

The seal chamber pressure of a horizontal split case pump is typically equal to the suction pressure. In this case, the suction pressure is given as 2 bar, so the seal chamber pressure would also be 2 bar.

The seal model 150 is not used on mixers or reactors normally.

186 uses Hastelloy C Metal bellows, 186HT uses AM350 or Inconnel 718 metal bellows for strength at high temperatures.