Safety in Petroleum/Petrochemical Industry
Safety precautions are required while transporting petroleum products through pipeline in Petroleum/Petrochemical Industry:
Petroleum products, crude oil, and natural gases are some of the more important products transported by underground pipelines.
The pipelines are usually buried about 1 meter underground and must be protected against corrosion. Leakage are likely to occur.
The pipelines have to be checked constantly.
The biggest danger to pipeline come from outside sources like un-authorized digging and from corrosion. Pipelines should be given special additional protection at various points along the route as road and river crossings.
During construction of a pipeline, all welds are visually examined.
Generally, a percentage are radio graphed to ensure that there is no cracking or undue slag intrusion and that there is suitable fusion between the weld and the parent metal.
The pipeline is wrapped to protect it against corrosion once it is buried. Pipeline control systems should be capable of recognizing and measuring leak conditions and initiating the appropriate action to shut down the system and minimize the amount of product leaked.
What is OISD? (For India Only)
OISD stand for Oil Industry Safety Directorate. It is an institute set up by the ministry of Petroleum, Govt. of India. It has full powers to formulate, issue, and review various standards on safety applicable to the oil, natural gas and refinery units. Those standards are to be exercised throughout the country.
Important aspects considered by OISD is given below to ensure Safety in Petroleum/Petrochemical Industry:
- Site selection.
- Location of industries.
- Factory lay out.
- Process technology.
- Engineering Design.
- Predictive & preventive maintenance.
- Periodical examination of certification.
- Area classification for installation.
- Lighting arrestor.
- Flame arrestor.
- Permit to work system.
- Process instrumentation.
- Corrosion prevention or control.
- Building structural stability.
Safety measures associated with filling of road tankers in Petroleum/Petrochemical Industry.
- The tankers must be duly approved, registered & licensed by RTO & Department of Explosives.
- They should undergo regular inspections, regular cleanliness, good condition of lights, breaks, horns, rear view, mirrors, static bonding etc.
- Examine safety valves, other fittings, test it and certified by competent person as per law.
- Smoking by drivers & helpers strictly prohibited.
- Fire extinguishers & PPEs must be readily available in tankers.
- Before loading/unloading must stop engine, must set break, turn off light and make Static bonding connection.
- If the tankers has it own unloading pump, must stop it before connecting or disconnecting loading lines.
- The driver must be present while loading/unloading done.
- Before tankers leaves, must stop discharge of the flammable product & remove hose.
- Never exceed the safe filling capacity.
- Immediately stop any Spillage or leaks.
- Park any leaky or defective tanker in such a way that there is no obstruction to ongoing traffic.
Safety measures associated with loading and unloading of Petroleum product tanker.
Following safety measures shall be follow while loading/unloading of petroleum product tanker.
- Avoid splash filling.
- Filling pipe touching bottom (dip pipe).
- Reduced filling rate.
- Control of overflow.
- Tanker bottom bonding/ grounding.
- Avoidance of switch loading.
- Safe sampling.
- Use of metallic dip rod for level measurement (manual gauging).
- Switching off vehicle engine during Loading/ unloading operations.
- Blocking of wheels to avoid accidental movement and hitting against equipment, pipe lines, and structures.
- Provision of emergency shut off / excess flow check valves.
- Proper line up between tanker & storage tanks.
- Availability of escape routes during emergency including avoidance of tanker movement nearer to plant operating areas.
- Display of product name, UN Number, NFPA hazard code symbol, HAZCHEM code, emergency contact details (phone number, address etc.)
- Approval, licensing by statutory authorities.
- Provision of Fire protection equipment including exhaust sparks arrestors.
- Availability of Personal Protective Appliances (PPA) and ensuring their usage.
- First aid box.
Hazards associated with bulk storage of petroleum products in Petroleum/Petrochemical Industry.
Following hazards are found in bulk storage of petroleum products.
- Flammable liquids are easily ignited and difficult to extinguish.
- Its vapours form explosive mixtures with air.
- Flammable liquids in closed containers offer only moderate fire risk.
- They however, become severe fire hazard when containers are open or leaky.
- Before handling containers should be carefully inspected and damaged or leaky containers if any, be segregated.
- Containers should not be dropped, rolled or handled in a manner that cause damage to them.
- Flammable solid materials become particularly hazardous under certain conditions.
- Some other are liable to heat spontaneously and ignites.
- Certain materials have the property of releasing flammable gases when in contact with water.
Health Hazards of bulk storage of LPG
Hazards of LPG
- Main hazards with LPG are Fire and explosion.
- Its flame can travel back to the source giving flash and cause fire & burn injury.
- It can cause cold burns to the skin due to its rapid vaporization and lowering of temperature.
- It’s very high concentration in air is anesthetic and on dilution it becomes suffocating.
- Heavy leaks give hissing sound or icing in the case of leak.
- Detect small leaks by soap solution.
- Its empty tank may still contain LPG vapour and if air enters in empty tank it can form an explosive mixture.
- Therefore it is must to purge by inert gas first and do gas-test before doing any work on it.
- Make sure location of the LPG storage installations are “above ground” and in the open air in a well ventilated position as per the separation distance covered under SMPV Rules and OISD guidelines.
- Make sure under ground or mounted vessels as such that the manhole and pressure relief valves are in ventilated position in accordance with the conditions.
- LPG vessels should not be located one above one.
- Concrete or compact ground underneath and free from pits, drains and culverts.
- Remove weeds, grass, shrub or any combustible material from the ground.
- Give slope to the ground beneath the vessels, connections and equipment containing LPG to drive away any dripping or leakage towards a safe area.
- Such evaporation area or catchments pit should be at least 3 M from LPG vessels and have sufficient capacity to contain the largest credible leak and well ventilated to permit safe desperation
- Gas detectors should be provided in the pit to give warning of any LPG Vapour.
Testing procedure of LPG storage vessel
- First of all, empty the tanks.
- Then purge it to ensure no vapor of LPG exist in the tank.
- If there is use of any coating material then remove it.
- Then carry out different tests like internal and external visual inspection tests, thickness test, etc.
- After correcting false parameters and ensuring its safer for usage, again use it.
Classification of petroleum products as per petroleum Act (India)
Under Petroleum Act, Petroleum products are classified into class A, Class B, Class C based on the flash points.
Class A Flash Point < 230°C. for e.g. Aviation Gasoline, Naphtha, Motor Spirit, benzene, Toluene, hexane, Pentane etc.
Class B 230°C < Flash Point < 650°C. for e.g. High Speed Diesel, Kerosene, Xylenes, Styrene, C-9 etc.
Class C 650°C <Flash Point < 930°C. for e.g. Furnace Oil, Light Diesel Oil etc.
The Petroleum products having flash point 930°C and above are exempted Petroleum products and do not fall under the range of the act & rules [e.g. Lube Oil, Bitumen etc.] unless it is stored along with any of the above class.
The Petroleum Act provides some exemptions for small quantities of Petroleum from having license for storage or possession.
Petroleum Class A 30 L Stored in approved containers.
B 2500 L Stored in approved containers
C 45000 L Stored as per provision under statutory provision.
DCS and its roll to ensure Safety in Petroleum/Petrochemical Industry
DCS (Distributed Control System) and PLC (Programmable Logic Controllers) can be termed as “Exclusive, need based application of computer technology for controlling the chemical or Petro chemical process.
The programs are made at the project stage and people are trained to operate the plant based on the logic sequences available in the PC. There is revolutionary improvement in the process industry both in terms of efficiency and safety due to use of DCS.
A well designed and operated system helps avoid many of the problems.
Advantage of DCS in terms of Safety.
- It has remote control system. So there is less chance for human error.
- It can avoid the contact of person at hazardous area.
- It has quick emergency shut-off facility.
- It can indicate signals and actions without operator interference like gas leakage & fire.
- It has facility to change process quickly.
Main sources of ignition in Refinery and Petro chemical industry
Main sources of ignition for fire hazards in refinery or petrochemical industries are as follows:
- Electrical arcs/sparks.
- Frictional sparks.
- Hot surfaces.
- Welding activities.
- Static discharges.
- Thermite action.
- Pyrophoric reaction that occurs when sodium is exposed to water.
- Chemical reactions.
- Mechanical sparks.
- Lightning strikes.
- Exhausts of combustion engines.