Preferred Utilities Manufacturing Corp.

31-35 South Street • Danbury • CTwww.preferred-mfg.com

Fuel Oil Handling Systems

Fuel System Design Considerations

Part 2

Additional Design Considerations

Oil Heating and Insulation Preventing Overflows Day Tank Flow Control Air Entrainment Fire Safety Relief Valves Multi-Tank Returns Vent Line Height Foot Valves Anti-Syphon Devices

Tank Heating and Insulation Aboveground Storage Tank (AST) – installed in a

cold climate – # 2 thru # 6 oil, heating requirements and insulation of tank

Emergency generators – Approximately 40 F is the cloud point of paraffin wax in # 2 fuel oil Thermopump System application

# 6 Oil Piping - heat trace the pipe and insulate or install FOS, FOR, steam and condensate return lines in a single carrier pipe with insulation

Use a Thermopump System or a winter blend of fuel oil

Tank Heating and Insulation

Tank Overfill Prevention Tank gauging with overfill alarm station HLS in tank to back up the tank gauge Model 1 Ground Level Spill Containment Type 2 In-Wall Spill Container Remote Overfill Alarm Station Mechanical fill line overfill prevention device

( Type 61 and 61F) Vent line with overfill alarm switch

Sidewalk or Driveway Fuel Fill

Spill Containers Model 1 In Ground Spill

Container» Drains oil spilled from

delivery disconnect into storage tank

» Designed to handle driveway traffic

» Removable bellows for easy fuel testing without pavement excavation.

Inside Fill Container

Model 2 In-wall Fill Cabinet

Provides 5 Gallon Containment For indoor storage tanks

with fill lines piped

to building walls Overfill alarm Alarm silence Display tank level

Model 2

In-Wall Fill Box with Sign

Inside Type 2 In-Wall Spill Box

In-Wall Spill Box Digital Display

Fil-A-Larm Overfill Alarm Box

HLS High Level Sensor

Day Tank Vent Detector

Flow Control

Filling Day Tanks in Multiple Tank Applications

Install Flow Control Manifolds One for each day tank Three valve by-pass arrangement for manual

operation and servicing, (2) Solenoid valves Options: Fuel filter, flow switch, oil meter,

indicator lights

Flow Control Manifold

Flow Control Manifold

Day Tank Location

Day tank above main storage tank gravity return Provide tank overfill drain to main tank

Day tank below main storage tank return pump system is required pump flow rate capacity must be larger than the pump

set supply system Add a PLS switch to the tank vent

Air Entrainment

Pipe the return line to the bottom of the tank to prevent aeration

Back Pressure Regulator BPRV Return riser pipe, install BPRV at the bottom of the

riser, set pressure to maintain a constant head to prevent the free fall of the fuel and entraining air

Syphon Breaker Day tank header system applications, can use in

conjunction with the BPRV

Air Entrainment

                                                    Separate the Fuel Oil Supply (FOS) and Fuel Oil

Return (FOR) Piping drop tubes in the tank to prevent the recycling of air

FOS, 4-6 inches off the bottom of the tank

FOR, 18-20 inches off the bottom of the tank, add a 90 elbow to direct return fuel away from suction

Air Entrainment

VACUUM BREAKER(OPTIONAL)

VENT

TRAP

RETURNRETURNRETURN

HEADER

SUPPLY SUPPLY SUPPLY

ENGINE #3ENGINE #2ENGINE #1

RELIEF

IN OUT

PUMP SET

Fire Safety Basics

Don’t Feed the FireStop the flow of the fuel

Fire Safety Shut-off Valves

Lever Gate Valve» Fully mechanical

» Emergency fuel line shut-off is mandated by many codes

» Fusible links open at 165F

» for pipe ranges 3/4" - 3"

Fusomatic Valve» Replaceable fusible element

» Fusible links open at 165F, May be manually opened/closed

» for pipes 3/4" or 1"

Fire Safety Shut-off Valves

Multiple Fusible Links Fuel Shut-off and Limit Switch Stops Pump

Type 110 Fire Valve

Anti-Syphon Valves

Stop Fuel Flow

Boilers or Hot Water Generators

FusomaticElectric Cut-offs

Relief Valves

A must with positive displacement pumps If the oil line is blocked, something will break Relief valves on pump set– piped into the return

line with no shut off valves Multiple tank systems with ball/gate valve

arrangement, pipe relief valve into pump suction, utilize pump flow switch for safety shutdown

Place a relief valve between two solid points to relieve hydraulic pressure from thermal expansion

Pump Set Relief Valves

Multiple Main Tank Returns

On multiple main tank applications, recommend utilizing a Tank Selector Valve that will never have a positive shutoff when changing tanks

If tank selector valve not desirable, recommend automatic ball valves with end switches. Pumps shut down during a tank changeover and will not restart until proper alignment is proven. This will also prevents a tank overfill due to improper valve alignment.

Two Tank Selector Valve

Replaces confusing array

of hand valves Simple lever operation

transfers both supply & return

lines from one tank to the other Designed with no “blind spots” where flow

could be blocked to or from the tanks Threaded or flanged connections available

Threaded Connection

Vent Line Vertical Height

Main Storage Tanks and some Day Tanks are only rated for 5 PSI. Tanks are not pressure vessels.

On overfilled tanks that do not provide for an overflow condition, the oil will go up the vent.

The static pressure at the bottom of the tank can exceed the pressure rating of the tank.

Remember that 2.6 ft of #2 oil = 1 PSI 13 feet/2.6 = 5.0 PSI PLS switch in the vent can sound an alarm or shut

off a pump.

Foot Valve Installation Install foot valves and check valves to prevent

loss of prime if top of the tank is below the centerline of the pump

Utilize an extractor fitting for easy removal of foot valve for maintenance and inspection

Extractor fitting can be a potential air leak. Insure they are properly sealed.

Foot valves are sometimes required with Anti-Syphon valves. An Anti-Syphon valve does not make a good check valve.

Insure the shipping plug is removed before installation.

Foot Valves

Maximum Height for ASV

Install Anti-Syphon Valve (ASV) if top of the tank is above the centerline of the pump

Maximum height for ASV – 20’ above centerline of pump

Above 20’ utilize a solenoid valve for an anti-syphon device

Single Source Fuel Handling

Preferred Utilities Manufacturing Corp

31-35 South Street • Danbury • CTT: (203) 743-6741 • F: (203) 798-7313

www.preferred-mfg.com