1、High liquid level design

(1) The design of fixed-roof tank storage high liquid level should be calculated according to the following formula:

h = H1 - (h1+h2+h3)

Where: h - tank design storage high liquid level, m;

H1 - height of the tank wall, m;

h1 - height from the lower edge of the foam generator to the top of the float level gauge tank wall, m;

h2 - the height of the maximum 10-15min tank feed conversion, m;

h3 - safety margin, m, 0.3m (including the thickness of the foam mixture layer and the expansion height of the liquid)

(2) Floating roof tanks, floating roof tanks, design storage high level should be calculated according to the following formula:

h = h4 - (h2 + h5)

Where: h4 - floating roof design maximum height (floating roof bottom), m. h5 - safety margin, m, may be 0.3m;

h5 - safety margin, m, can be taken as 0.3m (including the expansion of the liquid height and the margin required to protect the floating disk)

(3) pressure tank design storage height should be calculated according to the following formula:

h = H2 - h2

Where: H2 - liquid-phase volume to 90% of the calculated volume of the float level gauge tank height, m.

2、Low liquid level design

(1) should meet the requirements from the low level alarm within 10-15min from the pump will not occur cavitation.

(2) Floating roof tanks or floating roof tanks designed to store the low level should be 0.2m above the height of the floating roof drop bottom.

(3) It should not be lower than the highest point of the heater in the tube.