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Diagram #9 - DuraSite Portable Sample Vessel Instructions
Purpose: The DuraSite Portable Sample Vessel permits
the user to remove a liquid or gas
hydrocarbon sample from a pipeline or a sampling device.
This is accomplished without changing the pressure of the
product or exposing it to a
contaminant fluid. If properly used and maintained the
DuraSite will provide many years of safe,
accurate and clean sampling.
Use: The DuraSite is a very safe device to use. As with any
equipment dealing with flammable
products, it is mandatory that a good, thorough operator
training procedure be established prior to use.
Typical use of the cylinder would be as follows:
Step 1: (In The Lab) Connect a regulated inert gas supply
to the pre-charge valve. The product valve should be open.
By carefully controlling the
pre-charge valve and the regulator, the cylinder can be
slowly charged with pre-charge gas (NOTE: This should be
done slowly to prevent slamming the piston down to the
opposite end). The pressure on the pre-charge pressure
gauge should be brought to a reading of 10-50 psi above the
expected pressure of the product in the field . Close the pre-
charge valve and disconnect the gas supply. Check the
pre-charge valve, relief device, and the pre-charge pressure
gauge for leaks. Any leaks should be stopped before
continuing. The vessel should be placed in a padded
carrying case and made ready for field use.
Proceed to
EITHER Step 2, or Step 3 as
required for your application.
STEP 2: FOR COLLECTION OF SAMPLE VIA SPOT
SAMPLE OR FROM COMPOSITE
ACCUMULATOR VESSEL.
2a: Connect the product end of the pre-charged sample
vessel to the product supply.
(Sampler product removal valve, or Pipeline sample probe)
NOTE: the pre-charge pressure gauge reading should
be greater than the product supply
pressure reading. If not, repeat Step 1 above.
2b: Once the vessel is connected to the product supply, it
is necessary to vent a small amount of product prior to filling
the vessel. This assures fresh product and removes any air
or gas when dealing with liquids. This can be done by
loosening the product purge valve a very small amount until
the product is purged. After thorough purging, the
product purge valve should be tightened.
2c: The product pressure gauge reading should be 10-50 psi
below the pre-charge pressure gauge reading. By carefully
opening the pre-charge valve, the pressure becomes equal-
ized, then begins to drop below the product pressure. The
pre-charge valve should be carefully controlled so as to not
vent the pre-charge gas too fast.
2d: When the cylinder becomes a maximum of 80% full
(see volume indicator), all valves should be closed. The
product connection is slowly broken in order to vent any
trapped product. After vessel removal, all connections
should be checked for leaks and the pre-charge and product
valve ports capped to prevent leakage.
2e: Pack the DuraSite in appropriate carrying case to meet
D.O.T. guideline, with D.O.T.
paperwork and transport to lab for analysis.
STEP 3: FOR DIRECT CONNECTION TO
SAMPLER.
3a: Connect the sampler discharge port to the product inlet
port to the DuraSite using 1/8" stainless steel tubing.
3b: (Gas sampling) Connect the pre-charge port to the
DuraSite to the pipeline for pre-charge pressure (Proceed to
step 3d), or configured like the liquid sample application
below. (Step 3c)
3c: (Light sampling) Pre-charge the DuraSite as indi-
cated in Step 1, then install a pressure relief valve to the pre-
charge port and open the pre-charge valve on the DuraSite.
(The pressure relief valve should have a relief pressure
setting of approximately
100 psi above line pressure.)
3d: Open the product inlet valve of the DuraSite and the
purge valve on the sampler. Next open the purge valve on the
product end of the DuraSite and allow product to purge all
lines and connections out.
3e: Close purge valves and begin sample cycle.
3f: At the end of sample cycle, close product inlet valve on
the DuraSite and remove the DuraSite. Pack the DuraSite
in appropriate carrying case to meet D.O.T. guideline, with
D.O.T. paperwork and transport to lab for analysis.
Step 4: (In The Lab) Prior to analysis, the product should
be mixed. This is accomplished simply and efficiently by
inverting the cylinder end-over-end, causing the mixing ball
to fall through the product. Approximately 10-12 trips of the
mixing ball through the product assures a homogenous
solution.
Step 5: The regulated pre-charge gas should be recon-
nected to the pre-charge side of the cylinder. The pre-
charge gas supply should remain open during analysis.
Step 6: Purging a small amount of product from the vessel
removes unmixed product from the tee, relief device, gauge,
etc. The unit can now be connected to a chromatograph
and the product analyzed.
Step 7: After analyzing, the remainder of the product
should be dumped and the vessel properly cleaned. Normal
cleaning can be accomplished by rinsing the product end
with a petroleum solvent and flushing with acetone. If a
more thorough cleaning is required, the vessel should be
disassembled.
WARNING: A portable sample vessel should never be
filled to more than 80%. This allows a 20% pre-charge
cushion to absorb thermal expansion of the product.
Shipping: Extreme care should be taken when preparing a
vessel for shipment. Both valves should be capped to
prevent possible leakage. The vessel should be placed in
a snug-fitting, well-padded and durable case. All applicable
DOT regulations should be adhered to.
