In the domain of Diesel Generator (DG) operations, the unloading of diesel from
tankers into underground tanks is a critical procedure often overlooked in its
complexity. Many individuals handling this process lack awareness of the correct
steps and essential checks required for a seamless and secure operation. This
article aims to bridge this knowledge gap, providing a detailed guide for HSD
yard personnel and tanker operators. our commitment at Tristar Engineering and
Chemical Co. to safety, precision, and sustainable business practices, this guide
aligns with our shared vision of contributing to the well-being of our employees,
society, and the environment. Join us in exploring the intricacies of diesel
unloading, emphasizing safety measures, and fostering a deeper understanding of
this crucial aspect in our operational landscape.
Receipt of Product:
At the time of arrival of the tanker, the HSD yard personnel should check the
following details on the Invoice and compare the same with the Tanker
physically.
1.Tank Lorry No.
2.Seal Number / Security Lock Number.
3.No. of compartments and the quantity of the product contained therein.
4.The time tank lorry left Supply Point.
5.Recorded Density at 15 Degree C.
6.Dip rod with calibration certificate of the tanker compartment.
Safety Steps before Decantation / unloading.
1.Mobile Phones should not be allowed on the person checking the tanker
compartments, taking samples, taking dip reading etc.
2.Mobile phones should not be allowed in the HSD yard.
3.Ensure placement of portable Fire Extinguishers (ABC Dry Powder) / sand
buckets etc near Tanker unloading valves, decantation / unloading point on
the Underground tank and Tanker fuel tank. Other Fire extinguishers can be
placed appropriately at other points. Generally a minimum of 1 meter
distance should be maintained between the portable fire extinguisher and the
fire risk point.
4.Display appropriate safety message boards such as Unloading in Process,
Danger Keep Away, Authorized person entry, No Smoking.
5.Ensure person climbing on the tankers wears a safety harness, helmet and
required PPEs.
6.Ensure cables and electric boxes in the yard are flameproof and adequately
insulated.
7.Ensure adequate barricading is done so as to prevent unauthorized personnel
in the area.
8.Ensure the pump connected to the underground tank in which product is
being unloaded is isolated.
9.Ensure adequate earthing is provided to Underground tank, Tanker, buckets /
funnels etc which are being used in the unloading process.
Process of Decantation / unloading:
- Park the tanker on level ground ( Flat surface) for 10- 15 minutes to let the
product settle before carrying out the checks. - Before starting the operation on the tanker unloading, proper earthing
(Earthing resistance should be less than 4 OHMs) should be ensured. - The tanker discharge hoses should comply with all the safety requirements,
and under no circumstances, plastic/PVC hose pipes should be used. Use
only standard rubber Hose having electrical continuity with coupling hose no
metallic bend. - Ensure UGT tank should have space enough to unload the product.
- Check using dip stick the product level in the underground tank to ensure
there is enough space to accommodate the incoming fuel before starting the
unloading process to avoid spillage. - Check condition of the seal / security lock on the tanker delivery & manhole
covers against those mentioned in the invoice. - Take dip level of the product in all compartments with the dip rod duly
certified by Weights & Measures Department and provided with the tanker.
8.Check Weights & Measures markings on the dip rod at the bottom as well as
at the proof level. - Check for presence of water in each compartment by using water finding
paste. - Before commencing tanker decantation operation, the discharge from the
concerned underground tank should be stopped till the completion of
decantation. - Release master valve levers to ensure product fills the pipelines, where
tankers are normally calibrated with lines full, before checking dips (Refer
Calibration Certificate). - Ask the tanker driver to produce certificate of calibration which would
mention product level and proof level details. - During sampling operation only use metallic bucket or metal funnel and
ensure earthing between tanker and bucket / funnel. - Using a Tanker Sampler draw samples from each compartment on which
further tests are to be conducted. - Check that the Density of product @ 15 Degree C using ASTM Tables (53B) is
within +/- 1.2 kg/m3 as compared with the challan density for ascertaining
quality of product. Eg. if at the time of loading the density was 826 kg/m3
then at the time of unloading it should be between 826 kg/m3 to 827.2
kg/m3. - Keep filter paper to check the quality of MS / HSD for contamination. Visual
chart for water content of the MS/ HSD to check the haziness level in the
product with to know the approx. level of water contamination. (Tristar Diesel
Testing Kit) - In case of doubt as to the quality of product, contact the Supply
Location/concerned Area Field Officer for further instructions. - In the event of dip being short as per calibration certificate or water being
detected with water finding paste, the short quantity or presence of water
should be noted and informed to the authorities. - After decanting / unloading the product, ensure that the tanker is completely
empty before releasing the tanker. There are chances that the product is left
in the pipeline of the tanker. After unloading, close all the tanker valves and
run the tanker for few meters giving it a lot of jerks so that all the material
comes into the pipeline. Bring the tanker to rest and Drain the pipelines. - After decanting the product check the level of stock in the UGT before and
after decantation process and note the stock values. - Make appropriate entries in the stock register.
