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### Temperature Rise Mechanical Seal Formula and Calculator

Temperature Rise Mechanical Seal Chamber Formula and Calculator

The steady-state temperature of the fluid in the seal chamber is a function of a simple thermodynamic balance. The heat flow into the seal chamber fluid minus the heat flow out of the seal chamber yields a net heat flow. The fluid temperature will either increase or decrease depending upon whether the net heat flow is positive or negative. This is deceptively simple. In actual applications, the heat flows into and out of the seal chamber fluids are extremely complex.

There are several sources of heat flow into the fluid. These include heat generated due to friction and fluid shear at the seal faces, heat generated due to windage (or turbulence) caused by the rotating seal components, and heat conducted from the pump through the seal chamber and shaft (or positive heat soak). There are also several sources of heat flow out of the seal chamber. These include heat conducted back into the pump through the seal chamber or shaft (or negative heat soak) and heat lost to the atmosphere throughconvection and radiation.

The differential temperature, ∆T (in kelvin), can be calculated by the following equation:

Eq. 1
ΔT = ( 60,000 · Q ) / ( d · qinj · cp )

where:

Q = heat generation at the seal faces, kW;
qinj = injection flowrate, expressed in L/min;
d = relative density (specific gravity) of the injected fluid at pump temperature;
cp = specific heat capacity of the injected fluid at pump temperature, expressed in J/kg·K .

Related:

Reference:

• API/ANSI Standard 382 - Pumps Shaft Sealing Systems for Centrifugal and Rotary Pumps
• Rules of Thumb for Mechanical Engineers
J. Edward Pope, Editor