24.01.2016 Views

Centrifugal Pumps Design and Application 2nd ed - Val S. Lobanoff, Robert R. Ross (Butterworth-Heinemann, 1992)

Create successful ePaper yourself

Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.

362 <strong>Centrifugal</strong> <strong>Pumps</strong>: <strong>Design</strong> <strong>and</strong> <strong>Application</strong><br />

where P h = AP(b - k), lb/in 2<br />

P = pressure differential across seal face, lb/in 2<br />

b = seal balance<br />

k = pressure gradient factor<br />

The pressure gradient factor is normally taken as 0.5 for a given installation.<br />

The mechanical pressure for a seal is:<br />

where F sp = seal spring load, Ib<br />

a 0 = seal face area in. 2<br />

then the actual face pressure can be express<strong>ed</strong> as:<br />

The actual face pressure is us<strong>ed</strong> in the estimate of the operating pressure-velocity<br />

for a given seal installation.<br />

Figure 17-5. Pressure w<strong>ed</strong>ge opening force at the seal faces.

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!