Transcript 3.5.10 CETP Instructor PowerPoint Template

3.5.10
Unloading a Bobtail Cargo Tank of 3,501
Water Gallons or More in Metered Delivery
Service
Unloading a bobtail cargo tank in metered delivery
service at the bulk plant or an industrial installation
requires strict compliance with DOT cargo tank
unloading regulations.
In this module you will learn to identify:
1. Regulatory requirements for unloading cargo
tanks larger than 3500 water gallons capacity in
metered delivery service .
2. Procedures used for unloading a cargo tank in
metered delivery service at the bulk plant or an
industrial installation .
3.5.10 Student Book  © 2004 Propane Education & Research Council
Page 1
Regulatory requirements for unloading cargo tanks larger than
3500 water gallons capacity in metered delivery service.
49 CFR § 177.834—unloading attendance requirements
49 CFR § 177.840 (p)—unloading procedures for cargo
tanks in metered delivery service
49 CFR § 178.337-11—emergency discharge control
NFPA 58
LP-Gas
Code, 2001
edition
1—qualification of personnel,
4—transfer operations, and
6—transportation of LP-Gases
3.5.10 Student Book  © 2004 Propane Education & Research Council
Page 1
Regulatory requirements for unloading cargo tanks larger than
3500 water gallons capacity in metered delivery service.
DOT regulations require:
•
Cargo tank motor vehicles (CTMVs) with cargo tank water capacities of 3,501
gallons or more to be equipped with an off-truck emergency activation device
with a query feature that will automatically shutdown a transfer operation lasting
more than 5 minutes unless the unloading attendant responds to the query
feature to extend the unloading period. The emergency activation device must
be tested for proper operation at a distance of 150 feet from the vehicle within
18 hours prior to the first delivery of the day. (Figure 1.) If the test was not done
as part of the pre-trip inspection or as part of the previous day’s post-trip
inspection, do it prior to the cargo tank unloading operation .
Figure 1. Off-Truck Remote Shut-Off
Activation Device Test
3.5.10 Student Book  © 2004 Propane Education & Research Council
Page 2
Identifying Regulatory Requirements for Unloading Cargo
Tanks in Metered Delivery Service
DOT regulations require:
•
The unloading operator to check those components of the cargo tank discharge
system, including delivery hose assemblies and piping that are readily observed
during the normal course of unloading prior to the start of unloading operations.
The purpose of the discharge system component check is to assure that they
are of sound quality and without obvious defects detectable through visual
observation and listening for leaks or other unusual sounds. (Figure 2.)
Figure 2. Checking Readily Observed
Components of the Discharge System
3.5.10 Student Book  © 2004 Propane Education & Research Council
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Identifying Procedures Used for Unloading a Cargo Tank at a Bulk
Plant or Industrial Installation
•CTMVs with 3,501 water gallon or larger cargo tanks in metered delivery service
must be equipped with
•Emergency discharge control systems capable of shutting down the vehicle
engine and stopping the flow of propane by the use of a remote off-truck
emergency activation device with query feature, or
•These CTMVs may alternatively be equipped with a passive emergency
shutdown system that will automatically shutdown the vehicle engine and stop
the flow of propane within 20 seconds without human intervention in the event
of a complete delivery hose break .
•CTMVs with 3,501 water gallon or larger cargo tanks in other than metered
delivery service
•Must be equipped with a passive emergency shutdown system that will
automatically shutdown the vehicle engine and stop the flow of propane without
human intervention in the event of a complete delivery hose break.
3.5.10 Student Book  © 2004 Propane Education & Research Council
Page 3
Identifying Procedures Used for Unloading a Cargo Tank at a Bulk
Plant or Industrial Installation
•CTMVs with 3,501 water gallon or larger cargo tanks in both types of
delivery service (metered and non-metered) must be equipped with both—
a passive emergency shutdown system that will automatically shutdown the
vehicle engine and stop the flow of propane within 20 seconds without
human intervention in the event of a complete delivery hose break, and an
off-truck emergency shutdown device with query feature.
•For unloading operations of this last type of CTMV, the unloading attendant
must utilize the type of emergency shutdown system that is correct for the
type of delivery service used to unload the cargo tank.
3.5.10 Student Book  © 2004 Propane Education & Research Council
Page 3
Identifying Procedures Used for Unloading a Cargo Tank at a Bulk
Plant or Industrial Installation
Note:
Procedures for unloading bobtails are based on practices commonly used in the propane industry, manufacturers'
instructions, and provisions in NFPA 58. Before the filling operation, you should review bulk plant layout and
operating procedures. This step is detailed in Modules 3.5.2. Make sure you are familiar with the bulk plant
equipment, piping functions, and company operating procedures.
•
The use of an ACME adapter
(Figure 3.) may be needed to
make the transition from the
bobtail delivery hose assembly
to the bulkhead piping. If the
bulkhead is equipped with a
permanent transfer hose,
additional adapters may be
required to mate with the
transfer hose end adapters.
Figure 3. ACME Unloading Adapter
3.5.10 Student Book  © 2004 Propane Education & Research Council
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Identifying Procedures Used for Unloading a Bobtail at Bulk Plants
•
•
•
•
•
Specific U.S. DOT unloading regulations that are appropriate to the CTMV
emergency discharge control system must be applied. All required emergency
discharge control system and delivery hose inspections and tests must be made
before beginning the transfer operation.
The off-truck remote emergency discharge system activation device must be in
the possession of the unloading operator at all times during the unloading
operation.
The unloading operator must have an unobstructed view of the cargo tank and
delivery hose to the maximum extent practicable, except during short periods
when it is necessary to activate controls or monitor the receiving container.
If bulk plant transfer hose assemblies are used, they must be inspected and
determined to be sound and without rejection defects before the unloading
operation is started.
A qualified person must be in attendance at all times during cargo tank
unloading.
3.5.10 Student Book  © 2004 Propane Education & Research Council
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Identifying Procedures Used for Unloading a Bobtail at Bulk Plants
WARNING
Step 1:
During transfer, wear appropriate protective gloves and
clothing to prevent frostbite or freeze burn from exposure
to liquid propane.
Position the Cargo Tank Motor Vehicle .
•Check area for hazardous conditions and possible sources
of ignition. Sources of ignition capable of igniting LP-gas are
not permitted near a point of transfer. If any are found,
further operation should be delayed until the situation is
corrected. Be sure the vehicle is equipped with an 18 lbs.
B:C dry chemical fire extinguisher bearing a current
inspection tag or decal.
• Park vehicle at the unloading bulkhead in proper position
to make the transfer. (Figure 4.)
•Set the parking brakes and place chocks in front and
behind a rear wheel to prevent rolling of the vehicle.
3.5.10 Student Book  © 2004 Propane Education & Research Council
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Identifying Procedures Used for Unloading a Bobtail at Bulk Plants
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3.5.10 Student Book  © 2004
uid e
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Education & Research Council
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Identifying Procedures Used for Unloading a Bobtail at Bulk Plants
Step 2:
Check the Liquid Level Gauges on the Bulk
Storage Tank(s) to Assure Adequate Capacity
To Receive the Propane Without Overfilling.
•Even if the plant has more than one storage tank, it must be
determined how much propane can be safely added to each
tank. If a single tank will not hold the entire load, calculate the
distribution of the load among one or more additional tanks
3.5.10 Student Book  © 2004 Propane Education & Research Council
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Identifying Procedures Used for Unloading a Bobtail at Bulk Plants
To determine the amount of propane each plant tank will hold safely:
•
•
•
Gauge the contents of the plant storage
tank with the rotary or float gauge
installed in the tank head. Record the
percentage reading on the company form
or on a worksheet.
Using the temperature and specific
gravity of the propane in the bobtail cargo
tank, determine the maximum permitted
filling level in percent for the plant tank(s).
Use 0.508 for the specific gravity if plant
records do not indicate a different specific
gravity. Record the result on the
worksheet.
Subtract the bulk storage tank gauge
reading(s) from the maximum permitted
filling level.
•
Calculate the maximum amount of
propane that can be added to the storage
tank by multiplying the difference
between the two percentage numbers by
the water capacity of the tank in gallons.
If, for example, the gauge on a 30,000gallon storage tank shows that it is 40%
full and its maximum permitted filling
density at the present cargo tank
temperature is 85%. Multiply the
difference, 45% X 30,000 gallons. For
our example, a single 30,000- gallon
tank, 13,500 gallons can safely be added
to the bulk storage tank, an amount
greater than the propane capacity of the
bobtail cargo tank. Throughout the
unloading process, monitor the liquid
level gauges of all bulk storage tanks to
ensure that no tank is overfilled .
3.5.10 Student Book  © 2004 Propane Education & Research Council
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Identifying Procedures Used for Unloading a Bobtail at Bulk Plants
Step 3:
Connect the Bobtail Delivery Hose and the
Bulkhead Vapor Hose Between the Bobtail
and the Plant Bulkhead.
•Review and follow company procedures for checking the
operation of the ESVs installed in the plant. Be sure to
include a check of the remote operators and all fusible links.
If the ESVs will not operate properly, do not continue the
transfer operation; notify a supervisor. Check the condition
of each hose for any rejection criteria defect. (Refer to
Module 3.5.5.)
Step 4:
Open the Bulkhead Valves and Check the
Hose Connections for Leakage.
3.5.10 Student Book  © 2004 Propane Education & Research Council
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Identifying Procedures Used for Unloading a Bobtail at Bulk Plants
Step 5:
Insert a Meter Ticket Into the Bobtail Meter
Register (or Begin the Meter Delivery
Sequence on an Electronic Meter) and Reset
the Meter for Recording the Transfer.
Step 6:
Open the Required Valves in the Bobtail
Discharge System, Engage the PTO, and
Begin Pumping Using the Bobtail Pump.
Step 7:
Stop the Bobtail Pump:
•Without letting the pump run dry—when the liquid in the
cargo tank has been transferred to the bulk storage tanks; or
•Any abnormal operating condition or pump noises occur; or
•If the maximum permitted filling level of any bulk storage
tank is reached
3.5.10 Student Book  © 2004 Propane Education & Research Council
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Identifying Procedures Used for Unloading a Bobtail at Bulk Plants
Step 8:
Close All Bulkhead and Bobtail Valves and
Disconnect the Transfer Hoses.
•De-pressurize the hose connections after closing the hoseend valves and the cargo tank and bulk head valves, then
venting the trapped propane liquid and vapor
•As the bobtail delivery hose assembly is retrieved and
stowed in its travel position, inspect the full length of the
hose deployed during the unloading operation as required
by DOT regulations. (Figure 5.)
•Remove the adapter (male ACME to female ACME) used to
connect the delivery hose assembly and bulkhead and store
it in the designated place
•Replace dust covers on the bulkhead vapor hose, and the
bobtail filling valve connector.
3.5.10 Student Book  © 2004 Propane Education & Research Council
Page 7 & 8
Identifying Procedures Used for Unloading a Bobtail at Bulk Plants
Figure 5. Inspecting the Length of Hose
Deployed During Unloading
3.5.10 Student Book  © 2004 Propane Education & Research Council
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Identifying Procedures Used for Unloading a Bobtail at Bulk Plants
Step 9:
Prepare the Bobtail for Travel.
•Do a walk-around inspection of the bobtail to ensure
that all hoses and tools used in unloading are properly
stored.
•Remove and stow the wheel chocks.
•Start the engine and when ready, move the bobtail from
the unloading bulkhead to a secure parking area inside
the bulk plant.
3.5.10 Student Book  © 2004 Propane Education & Research Council
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Time to See If You Got the Key Points of
This Module…
• Complete the Review on page 9 & 10.
• See if you are ready for the Certification
Exam by checking off the
performance criteria on page 11 &
12.
3.5.10 Student Book  © 2004 Propane Education & Research Council
Pages 9 - 12