Tanks Construction & Rim-seal system

Loss Factors

KRa (Ib.mole/ft.yr)

KRb (Ib.mole/(mph)n.ft.yr)

n

 

 

 

 

Mechanical-shoe seal

Primary only

5.8

0.3

2.1

Shoe-mounted secondary

1.6

0.3

1.6

Rim-mounted secondary

0.6

0.4

1.0

Liquid-mounted seal

Primary only

1.6

0.3

1.5

Weather shield

0.7

0.3

1.2

Rim-mounted secondary

0.3

0.6

0.3

Vapor-mounted seal

Primary only

6.7

0.2

3.0

Weather shield

3.3

0.1

3.0

Rim-mounted secondary

2.2

0.003

4.3

Table 5: Rim seal loss factors for floating roof tanks.