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Suction energy

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The amount of energy in a pumped fluid that flashes into vapor and then collapses back into liquid in the higher pressure area of the impeller inlet determines the extent of the noise and damage from cavitation. This guide calculates the suction energy of an impeller and lets you know if the suction energy level is low, high, or very high.
Guidelines for NPSHmargin are also provided.

GPM8, Goulds Pump Manual, Copyright 2004 Goulds Pumps, Marketing Communications, ITT Industries, 714.

Step 1: Suction Energy
1.1	Pump Type (E for endsuction or H for horizontal split case)
1.2	Liquid Volatility (V for Volatile, N for Non-volatile)
1.3	Impeller Eye Diameter (inches) Note: If the impeller is not accessible, use 90% of suction nozzle for end suction pumps and 75% of suction nozzle for double suction and split case pumps.
1.4	RPM
1.5	Flow @ BEP (gpm)
1.6	Specific Gravity
1.7	NPSHa (ft) @ BEP
1.8	NPSHr (ft) @ BEP
1.9	Safety Margin (ft) Note: Use 2 to 5 feet for upset conditions.
1.10	Suction eye(s)
Step 2: Solve
2.1	Proof steps	Show proof steps
2.2	Solve for suction energy