Why is gas seal dry?
Dry gas seals use a separation seal on the bearing side of the seal as a barrier. The purpose of the barrier seal is to prevent lubricating oil from migrating along the shaft and into the dry gas seal. This seal also prevents any gas leakage from the dry gas seal from leaking into the bearing cavity.
What is compressor dry gas seals?
Dry gas seals are basically mechanical face seals, consisting of a mating (rotating) ring and a primary (stationary) ring (Fig. 3). A sealing gas is injected into the seal, providing the working fluid for the running gap and the seal between the atmosphere or flare system and the compressor internal process gas.
What is the function of separation gas in dry gas seal?
A separation gas (typically nitrogen or air) is injected into the barrier seals. The primary function of the barrier seal is the prevention of lube oil migration into the gas seal. The barrier seal also serves as the last defense in the event of a catastrophic failure of the primary and secondary gas seal.
What is dry gas seal hang up?
It is common for dry gas seals to exhibit excessive leakage to the primary vent immediately on startup after extended periods of compressor downtime. This condition, known as hang up, occurs when the balance diameter o-ring “sticks” to its mating (sliding) surface because of friction.
What is the difference between Wet seal and dry seal?
Wet seals are preferred where dangerous chemicals are involved in the process. The reason is that if the seal fails, the vapors will be trapped in the barrier fluid and will have little chance of entering the atmosphere. With a dry seal the vapors have a better chance of escaping.
What is a dry seal?
If the impression is made purely as a relief resulting from the greater pressure on the paper where the high parts of the matrix touch, the seal is known as a dry seal; in other cases ink or another liquid or liquefied medium is used, in another color than the paper.
What is dry gas?
dry gas, natural gas that consists of little more than methane, producing little condensable heavier hydrocarbon compounds such as propane and butane when brought to the surface. In the United States, dry gases are defined as those that contain less than 0.1 gallon of condensables per 1,000 cubic feet of produced gas.
What is seal gas panel?
A Cobey Gas Seal Panel is designed to supply seal buffer gas to the shaft seals of various rotating compressors, providing containment of these process gases. The panel includes filters, pressure/flow control valves and various instruments to condition, control, and monitor the gas into and out of the dry gas seals.
Where are dry gas seals used?
Non-contacting dry gas seals are often used on compressors for pipelines, off-shore applications, oil refineries, petrochemical and gas processing plants.
How does a dry gas seal work?
Dry gas seals are non-contacting, dry-running mechanical face seals that consist of a mating (rotating) ring and a primary (stationary) ring. When operating, lifting geometry in the rotating ring generates a fluid-dynamic lifting force causing the stationary ring to separate and create a gap between the two rings.
What is a wet gas seal?
Centrifugal compressors have seals on the rotating shafts that prevent the high-pressure natural gas from escaping the compressor casing. These seals can be high-pressure oil (“wet”) seals or mechanical gas (“dry”) seals, which act as barriers against escaping gas.
What is the difference between a pocket seal and desk seal?
The table seal, commonly known as desk seals, were made for more heavy duty work, and so are heavier and sturdier compared to pocket common seals. Pocket common seals is easier to carry around and transport even when outdoors so that’s one advantage.