Preferred Utilities Manufacturing Corp.

Preferred Utilities Manufacturing Corporation31-35 South St. • Danbury • CT

www.preferred-mfg.com

Fuel Oil Sizing Program Overview

Introduction

PC Based Program Sizes Typical Fuel Oil Piping Systems Helps to determine “workability” of overall

application Helps to sizing suction and discharge piping

Day Tank Schematic

Determining Pump Capacity

For day tank systems rate of use vs. duty cycle determines pump flow length of time without power determines tank size E-Gen sets – “RULE of THUMB” 7 GPH / 100kw E-Gen sets - “RULE of THUMB” 4:1 , pump runs 25% of time.

For burner systems parallel loop, total burning rate plus total return flow series loop, total burning rate plus return flow of last burner

only

Pick pump-motor pair with next greater flow rate Motor HP based on PSI required

Maximum Inlet Suction

Atmospheric pressure (30" Hg) provides the force to get oil into the pump

Most pumps can produce a 20" Hg vacuum Good practice limits suction to a 15" vacuum or less Typical piping loss is 5" Hg This leaves 10" Hg for static lift, or 12' of oil Pump should not be located more than 12' above the

bottom of the tank

Determining Inlet Suction

Suction at pump inlet Add gravity head plus: Friction losses

Friction loss through suction piping convert fittings, valves, etc. to equivalent

diameters add total length of pipe to equivalent for fittings add loss through strainer

Increase pipe size or lower pump to suit

Pressure Drop through Pipe

Flow, Gallons per hour

Pressure drop through pipe,Number 2 Fuel Oil

Equivalent Diameters

» ball valve, full ported 3» check valve, lift type 600» check valve, swing type 100» foot valve, poppet type 420» globe valve 340» gate valve, full ported 8» plug valve 18» 90 degree elbow 30» 45 degree elbow 16» Tee, through run 20» Tee, through branch 60

Suction Piping Precautions

If both pumps in a duplex set may be run together, use total flow in calculations

Figure static lift from bottom of tank Use a 100% safety factor for strainer drop Use a 40 or 100 mesh strainer for #2 oil Use worst case viscosity in figuring loss

Priming the System

Try to keep pump close to tank Eliminate “up and over” lifts Add a priming funnel to the high point Do not allow pumps to run dry If possible, always use a foot valve to hold

prime Pressure test all suction piping

Some Terminology Operating Pump Suction: This value is displayed on the

screen at the suction side of the pump. This value is the total summation of all losses encountered on the suction side of the pump.  

Priming Pump Suction: This value takes into account the vertical lift of a dry system, and may also be referred to as the priming static lift. If a pump looses its prime, and the piping system is dry, the static lift may not be the same as the priming static lift. Therefore, the Priming Pump Suction must be examined as well as the Operating Pump Suction. This value takes into account the vertical distance of piping that might go above the centerline of the pump, before connecting with the pump.

S.G: Density of a fluid compared to the density of water. 

Discharge Piping

Pressure at pump discharge Add pressure needed at point of use plus total gravity head and pipe losses

Generally, discharge piping is smaller than suction piping

A Back Pressure Regulating Valve may be used to regulate pressure at point of use (boilers)

Viscosity as a Function of Temp.

Miscellaneous Cautions

Beware of entrained air locate return and supply at opposite ends of tank

Avoid high lifts and “traps” Allow for easy priming of pumps Provide adequate vent lines Provide properly sized day tank overflow lines Design the system so it can be tested regularly Don’t overlook controls

Loading the Fuel Oil Sizing Program

Opening Window - Select New or Existing File

Discharge Piping Selection

Application Selection Page

Opening Overview Display

Suction Piping Selection

Discharge Piping Selection

Final Overview Display

Pop Up Windows

Report Printing

Example

P1 P2

10feet

10feet

300 gph

Required5 psi

100 feetof 1 inch

Suction pipe

200 feetof 1 inch

Discharge pipe

Exercise 1For No. 2 Fuel OilDetermine:P1 and P2Select Pump Set 100

feet

Storage Tank

Rule of THUMB

Head Vacuum5 ft of No. 2 Oil = 4 " Hg

Head Pressure5 ft of No. 2 Oil = 2 psi

Example

P1 P2

5feet

15feet

400 gph

Required5 psi

100 feetof 1 inch

Suction pipe

300 feetof 2 inch

Discharge pipe

Exercise 2For No. 2 Fuel OilDetermine:P1 running and priming, P2ASV Spring SizeSelect Pump Set

200feet

ASV

Storage Tank

17.5feet

Rule of THUMB

Head Vacuum5 ft of No. 2 Oil = 4 " Hg

Head Pressure5 ft of No. 2 Oil = 2 psi

Pressure Drop through Pipe

Flow, Gallons per hour

Pressure drop through pipe,Number 2 Fuel Oil

Preferred Utilities Manufacturing Corp

For further information, contact...

Preferred Utilities Manufacturing Corporation31-35 South St. • Danbury • CT

T: (203) 743-6741 • F: (203) 798-7313www.preferred-mfg.com