Seals Flashcards
What type of cut is a skived cut?
Diagonal cut
What is the recommended compression range for a dynamic O-ring?
10 to 30%
What type of seal consists of a complicated network of grooves to create a seal?
Labyrinth seal
What kind of material is neoprene?
Type Of rubber
What is often used in connection with labyrinth seals to provide complete sealing in turbines?
Carbon seals
What is used to create the force of compression required for sealing flanked with a gasket?
Bolts
What must be completed before any gasket or packing maintenance is carried out
All source of energy must be removed and secured
When tightening, bolt flanges, what order should you follow?
Star pattern in several steps
Which type of seal is flange gasket
Static seal
Which method is the best to use when cutting packing range to repack a stuffing box?
Wrap, packing material around a man drill of the shaft size
When tightening a pack in gland, how many terms must you turn each nut at a time?
Each nut 1/6 of a turn or flat at a time
How many drops of leakage per minute is recommended to properly cool and lubricate the packing within a stuffing box of a pump
40 to 60
How are oring sized
Using inside diameter and thickness
What is the number one cause of pump down time?
Ceiling or packing failure
What is a big concern when using permatex type of gasket maker?
Permatex may fall into piping system
What choice would you consider when using a whole punch to make the whole bolt in a gasket?
Use a soft base under the material
What are labyrinth seals?
Non positive seals which have a tongue and groove design
Advantages of quenching?
Prevents leakage of corrosive ou toxic fluids.
Prevent crystallization ground the contact face
Maintain A constant operating temperature and minimize any heat transfer along the shaft.
Where are lip seas use?
Used in low Pressure areas (2 to 10 psi), primarily used on rotating shafts
What is a diaphragm seal?
Positive seal which has a flexible membrane which spans between the stationary and moving parts.
What are the two styles of diaphragm seals?
Flat diaphragm seal - designed for a small amount of movement
Rolling diaphragm seal- moulded membrane and rolls on the two mating surfaces as it moves
What is a ring seal?
Non-positive seal which is mounted into a groove in the housing. Made out of cork, felt, leather, or synthetic rubber
What is a wiper (scrapper)
Non-positive seal mounted on the stationary housing.it flexes against axially moving parts
What are boots and bellows ?
Positive seals which have one and secured to the housing and the other to-the moving parts. Boots are used for short movements (strokes) and bellows for long ones
What are the three categories that packing is divided into?
Compression, automatic, floating
What determines the #of bolts needed ?
Thickness of metal
Seals that prevent fluid from leaking from one side of a system to the other is called -
Positive seal
Seals which control the amount of such leakage are called -
Non-positive seals
