Tank Wagons Overview and Safety Features

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Questions and Answers

What should be done if a heavy leakage cannot be stopped by closing the valves?

Immediately initiate refueling operations.

Evaluate leaks and determine repair materials and techniques. (correct)

Ignore the leakage until it resolves itself.

Shut down all operations on the site.

What is the recommended action to identify liquid leaks from LPG tanks?

Apply soapy water to locate the leaks. (correct)

Rely on smell alone to detect the leaks.

Use a pressure gauge.

Conduct a visual inspection under direct sunlight.

Which of the following must be ensured during the loading and unloading of tanks?

The loading/unloading connections can be loosely attached.

Handbrakes must be put on and secured to prevent movement. (correct)

Operations can proceed without supervision if an experienced operator is present.

Everything can be done remotely without physical presence.

Which of the following is a precaution to be taken for heavily leaky wagons?

Affix 'Dangerous' labels on both sides of the wagons. Signup and view all the answers

Where should the tank preferably be placed during loading/unloading?

Under shade and secured properly against movement. Signup and view all the answers

What is the primary purpose of a safety valve on a tank wagon?

To prevent the build-up of excess pressure inside the barrel Signup and view all the answers

Where is the safety valve typically fitted on a tank wagon?

On the diaphragm plate inside the dome or separate opening Signup and view all the answers

What is the function of the relief valve in a tank wagon?

To release built-up pressure exceeding the working pressure limit Signup and view all the answers

What does a frangible disc do in a safety vent system?

Ruptures at a specified pressure to release excess pressure Signup and view all the answers

Which of the following is true about the compressed air valve on tank wagons?

It is utilized for unloading contents using compressed air Signup and view all the answers

At what point does the rupture pressure for the safety vent disc occur?

When the working pressure limit is exceeded Signup and view all the answers

What material is typically used for the frangible disc in a safety vent?

Lead or any approved material not affected by lading Signup and view all the answers

What should be done before steam cleaning a pressure vessel tank?

Ensure all gas has been discharged to the atmosphere. Signup and view all the answers

Which type of tanks is mentioned as not requiring the removal of the manhole cover for steam cleaning?

BTPN tanks Signup and view all the answers

What is the purpose of inserting a pipe through the manhole during steam cleaning?

To blow steam towards both ends of the barrel. Signup and view all the answers

How long should the interior of the tank barrel be steamed?

12 hours Signup and view all the answers

What should be done with the condensed steam collected in the tank barrel?

Remove it and leave the tank exposed to the atmosphere. Signup and view all the answers

What method can be used to test for traces of ammonia in a tank barrel?

Use red litmus paper to test the specimen. Signup and view all the answers

Which of the following does NOT apply to the entry of staff in the tank barrel during steam cleaning?

There should be no entry at all. Signup and view all the answers

What is the purpose of using Nessler's test with the water specimen from the ammonia tank barrel?

To detect traces of ammonia in the water. Signup and view all the answers

What safety measure should be followed when steam cleaning a tank?

Ensure isolation of the berthing siding from other traffic. Signup and view all the answers

What should be done if a drop in pressure is observed during a hydraulic test?

Reduce the pressure by 20% Signup and view all the answers

What is the maximum weight allowed for the hammer used in the thorough test of welded seams?

5 Kg Signup and view all the answers

What should be done after performing the hammer test on the welded seams?

Raise the pressure to the full test pressure and maintain it for at least 30 minutes Signup and view all the answers

For ammonia tanks, what is the hydraulic test pressure specified?

33.25 Kg/cm2 Signup and view all the answers

What is the testing pressure for tanks used for corrosive liquids like caustic soda?

4.5 Kg/cm2 Signup and view all the answers

What must be done to the safety valve before filling petrol tanks for a hydraulic test?

Remove it from its seating Signup and view all the answers

Which of the following steps is NOT required when performing a hydraulic test on petrol tanks?

Tighten the safety valve without removing it Signup and view all the answers

During the pressure testing process, what should happen to the tank barrel?

It should remain secured to the underframe Signup and view all the answers

What is the correct interval for striking the plates during the hammer test?

6 inches Signup and view all the answers

What material should the hammer used for testing be made of?

A softer material than the barrel plate Signup and view all the answers

What should be the condition of the master valve before certifying a tank wagon fit for loading?

It should be leakage-free while the bottom discharge valve is open. Signup and view all the answers

What is essential for the blank flange of a tank wagon?

The gasket must be of the proper material between the flange and valve flange. Signup and view all the answers

What could cause leaks in tank barrels?

Improperly secured valve seats. Signup and view all the answers

What precaution should be taken in the case of an ammonia gas leak?

Those nearby should remain on the windward side of the leak. Signup and view all the answers

What must be confirmed about the bottom discharge valve before loading?

It should function properly and be fluid-tight. Signup and view all the answers

How can tank barrels be marked if they have cracks?

They must be marked as sick. Signup and view all the answers

Which of the following does NOT pose a risk for leaky tank barrels?

Improper practices of steam cleaning wagons. Signup and view all the answers

What is a characteristic of ammonia gas that helps in identifying its presence?

It has a characteristic pungent odor. Signup and view all the answers

What should be avoided when working around empty tank wagons?

Entering the tank without proper testing. Signup and view all the answers

What is one reason for leaky tank barrels related to foreign materials?

They can cause mechanical injuries to the valve face. Signup and view all the answers

What should be ensured regarding the tank wagon during loading in terms of capacity?

It is not overloaded beyond its carrying capacity. Signup and view all the answers

What type of tools is recommended for use during handling operations to prevent sparks?

Brass tools Signup and view all the answers

Which of the following measures should be taken when dealing with the spillage of acid?

It should first be neutralized with hydrated lime. Signup and view all the answers

What should be used to connect the tank for loading with an air compressor?

A globe valve Signup and view all the answers

What is the maximum pressure that should not be exceeded in the tank during loading?

30 psi Signup and view all the answers

What is the minimum electrical clearance requirement from the contact wire as per IRSOD?

270 mm Signup and view all the answers

What is the maximum allowable outward projection of metallic sealing wire from the eyebolt hole?

One inch Signup and view all the answers

Which practice regarding metallic sealing wires is considered incorrect?

Winding sealing wires loosely around eye bolts Signup and view all the answers

What is necessary to ensure anti-theft protection of the dome cover?

Sealing on two adjacent bolts Signup and view all the answers

What should be done with metallic sealing wires after unloading operations?

Remove them from the dome cover Signup and view all the answers

What potential hazard can occur due to the improper sealing wire arrangement?

Electrical tracking fires Signup and view all the answers

What is the consequence of allowing long uncut lengths of sealing wires to hang?

Breaching electrical clearance requirements Signup and view all the answers

What should be done after every interruption of the welding arc?

Restart ahead of the previous deposit and fill the crater. Signup and view all the answers

What is the preferred method for welding a stiffening plate on an old design wagon?

Weld using the angle if the bearing plate is inside. Signup and view all the answers

What aspect of the safety valve requires careful attention during maintenance?

The valve's adjustment and need for testing. Signup and view all the answers

What should be examined closely to prevent leaks from fittings of pressure vessels?

The condition of packing and seals. Signup and view all the answers

What is a crucial step to take before attempting to change resilient seals in LPG tank wagons?

Lower the tank's pressure to within 10 pounds of the operating pressure. Signup and view all the answers

When tack welding a stiffening plate, which method should be used?

Tack weld the plate from outside only. Signup and view all the answers

What is the first action to take when a hydraulic pressure of 2.8 Kg/cm2 is reached in BTPN wagons?

Close the control cock. Signup and view all the answers

What method should be used to detect cracks in a tank if a magnetic crack detector is unavailable?

Dye penetration test. Signup and view all the answers

What is necessary to ensure successful welding reinforcement at the stiffening plate?

Flushing the reinforcement with the parent metal. Signup and view all the answers

When repairing cracks in tanks used for corrosive liquids, what is the most appropriate method if the cracks affect the plate's strength?

Cut out the affected area and replace it with a patch. Signup and view all the answers

What must be ensured during the pneumatic test of a safety valve?

The valve must be vapor tight against leakage. Signup and view all the answers

Which preventive measure is significant for leakage prevention regarding packing and seals?

Regular inspection for deterioration and dirt. Signup and view all the answers

What should be done after a drop in hydraulic pressure during a hydraulic test?

Inspect the joints first for leakage. Signup and view all the answers

Which of the following is a requirement for a workshop performing repairs on pressure vessels?

It must be equipped for radiographic examination. Signup and view all the answers

What common issue do tanks for the transport of corrosive liquids face?

Pitting and cracking. Signup and view all the answers

If pits in a tank plate are not deep enough to compromise strength, what should be done?

Weld the pits and grind them flush. Signup and view all the answers

Who should inspect pressure vessels that require repairs?

A competent authority approved by Chief Controller of Explosives. Signup and view all the answers

What is the ideal approach when multiple pits are closely grouped in a tank?

Chip out the affected area and replace it. Signup and view all the answers

What should be done if a frangible disc in the safety vent ruptures?

It must be replaced with a new compliant disc. Signup and view all the answers

Which valve should remain open during the testing of the bottom discharge valve?

The master valve. Signup and view all the answers

What is the maximum hydraulic pressure for testing the globe valves?

0.35 to 0.56 Kg/cm2 (5 to 8 psi) Signup and view all the answers

After what specific condition should safety valves on petrol tanks be pneumatically tested?

After any repairs or periodic overhauls. Signup and view all the answers

What must be done to the tank barrel during the hydraulic test of the master valve?

It should be filled with a minimum height of 150 cm of water. Signup and view all the answers

Which discusses the safety vent associated with frangible discs?

It should rupture at pressures exceeding predetermined values to allow excess pressure release. Signup and view all the answers

What could indicate that excessive pressure has built up in a tank wagon?

A ruptured frangible disc on the safety vent. Signup and view all the answers

What is the pressure range for pneumatic testing of safety valves specifically for petrol tank wagons?

0.35 to 0.56 Kg/cm2 Signup and view all the answers

How should a leaking valve be addressed before fitting it onto the tank?

It needs to be replaced if leaks are found. Signup and view all the answers

What is essential when performing a hydraulic test for a bottom discharge valve?

The master valve needs to remain open during testing. Signup and view all the answers

Study Notes

Tank Wagons

Tank wagons are a specialized class of rolling stock, classified by the product they carry and their design.
Categories include tanks for pressure vessels, corrosive liquids, highly flammable products (like petrol), and middle distillates of petroleum.
Appendix B of IRCA Part III (latest edition) provides information on mechanical codes and product details.
Four-wheeler and UIC-bogey tank wagons are no longer included in this manual.

Constructional Details

Underframe: Similar to other IRS wagons, but with saddles for mounting the barrel. Refer to Chapter 5 for repair and maintenance.
Barrel: Cylindrical, typically constructed from low-carbon structural steel (IS:2062 Fe 410CuW).
Saddles: The barrel is positioned on saddles welded to the underframe, facilitating longitudinal placement.

Safety Fittings

Safety valves: Prevent excess internal pressure. Locations and pressure specifications are detailed in Table 9.2.
Relief valves: Release pressure exceeding the working limit. Table 9.2 specifies wagon types with relief valves.
Safety vents: Consisting of frangible discs (lead or other materials), these rupture at specified pressures.
Compressed air valves: Control the discharge rate of contents unloaded by compressed air.
Vapour extractor cocks: Extract vapour from the tank during filling.

Overhauling of Tank Wagons

Periodical overhauling should be performed in mechanical workshops.
Specific periodicities for different wagon types are outlined in Table 9.3.

Interior Examination

Internal examination/repair of tank barrels is only permitted when the barrel is free of toxic or flammable fumes.
It is crucial that the barrel is thoroughly steam cleaned/washed to remove any residues.

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Description

This quiz delves into the specifics of tank wagons, including their classifications based on the products they carry. It covers construction details, safety fittings, and refers to relevant mechanical codes found in the IRCA guidelines. Test your knowledge on the design and safety mechanisms of tank wagons.