Under Pressure

Under Pressure Ch 17: 

Under Pressure Ch 17 Ben Washer

Topics : 

Topics Pressure Hazards Some Laws Press Hzd Sources Boilers High Temp Water Hzd Unfired Press Sys Cracking Hzd in Press Vessels Nondestructive Testing Of Press Vessels Pressure Dangers to Humans Decompression Measurement of Press Hzd Reduction of Hzd

Pressure, meet Hazard..?: 

Pressure, meet Hazard..? Pressure= In Physics, the force exerted against an opposing fluid or thrust distributed over a surface. Hazard= A condition with the potential to cause injury or damage to personnel or equipment. Pressure Hazard= Dangerous condition where things can go boom.

What is Boyle’s Law? : 

What is Boyle’s Law? Boyle’s Law is one of the laws in physics that concern the behaviour of gases When a gas is under pressure it takes up less space: The higher the pressure, the smaller the volume Boyles Law tells us about the relationship between the volume of a gas and its pressure at a constant temperature The law states that pressure is inversely proportional to the volume

Human meets Pressure Hazard.: 

Human meets Pressure Hazard. The many sources of pressure hazards include Natural and Manmade instances. Swimming too deep in a pool made by man people. = decompression sickness. Hypoxia- too little oxygen in lungs Hyperoxia - too much oxygen in me blood= instant sobriety. Nitrogen Narcosis- Higher than normal

Slide 6: 

Level of nitrogen pressure. Don’t use a pressure vessel in any manner other than it is designed for.

Boilers and there tendency to blow up: 

Boilers and there tendency to blow up

High Temp Water Hazards: 

High Temp Water Hazards

Unfired Pressure Vessel Hazards: 

Unfired Pressure Vessel Hazards

High Pressure Systems Hazards: 

High Pressure Systems Hazards Leaks- pretty obvious. Pulsation Vibration Release of high pressure fluid and or gases Whiplash from high pressure pipe. Whack! Common Fixes Use Vibration Dampeners, also limit the number of joints in the system. Use pressure gauges.

Pressure Vessel breakdown: 

Pressure Vessel breakdown A typical pressure vessel consists of shell (body of the vessel), closure heads, openings for inspection and instrumentations, attachments and a combination of nozzles for pressure relief or other purpose, and supports

Pressure Vessels and Piping: 

Pressure Vessels and Piping The pressure in a vessel increases as the temperature of the vessel increases. This pressure is a potential danger. Refrigerant cylinders should be stored in the upright position. Larger cylinders should be moved only when the protective cap is in place. Larger cylinders should be secured to carts designed for moving cylinders. Always wear gloves and eye protection.

Types of Pressure Vessels: 

Types of Pressure Vessels Deaerator Vessels- remove noncondensible gases. Used in Power Gen Plants, aslo Pulp and Paper processing. Amine Vessels- remove hydrogen sulfide from petrol refineries, gas treatment, and chemical plants. Wet Hydrogen Sulfide Vessels- Water hydrogen sulfide ie ‘wet’ are made from low strength steel as it will react less with dissolved hydrogen.

Types of Pressure Vessels Cont.: 

Types of Pressure Vessels Cont. Ammonia Vessels- used in refrigeration chemical and chemical processes. Usually spheres of carbon steel. Typical cracks near welds. Pulp Digester Vessels- Paper mill smell. Ohhh yeah.. Common failure in cracks along welded seams from Corrosion.

The main causes of failure of a pressure vessel : 

The main causes of failure of a pressure vessel  Faulty Design  Operator error or poor maintenance  Operation above max allowable working pressures  Change of service condition  Over temperature  Safety valve  Improper installation  Corrosion  Cracking  Welding problems  Erosion  Fatigue  Stress  Improper selection of materials or defects  Low –water condition  Improper repair of leakage  Burner failure  Improper installation  Fabrication error  Over pressurisation  Failure to inspect frequently enough  Erosion  Creep  Embrittlement  Unsafe modifications or alteration  Unknown or under investigation

Pressure Vessel Cracking: 

Pressure Vessel Cracking Cracking typically leads to ruptures and leaks which leads us to blasts effects. The sudden expansion of the contents of the vessel. = Pressure Hazard very toasty. Suffocation, poisoning, chemical or heat burns, and lastly shrapnel from fragmentation.

Preventive Maintenance: 

Preventive Maintenance Test, retest, and test again.

Nondestructive Pressure Vessel Testing: 

Nondestructive Pressure Vessel Testing Visual Exam- Liquid Penetration- Magnetic Particle - X-ray- Ultrasound- detects surface or near surface defects. Detect problems within the material of the vessel

Visual Examination: 

Visual Examination Look at it!

Liquid Penetration : 

Liquid Penetration Place special liquid penetrant over an area, let it seep in. Remove liquid then apply developing agent and fluorescent chemicals to detect disconformities.

Magnetic Particle Test: 

Magnetic Particle Test

X- Ray: 

X- Ray

Ultrasonic: 

Ultrasonic

Pressure, Humans, and Danger: 

Pressure, Humans, and Danger

Decompression Procedures: 

Decompression Procedures

Measurement of Pressure Hazards: 

Measurement of Pressure Hazards

Pressure Hazards Reduction: 

Pressure Hazards Reduction Improperly operated or maintained pressure vessels can fail catastrophically, kill and injure workers and others, and cause extensive damage even if the contents are benign . Requirements for pressure vessels vary widely from state to state . Some laws include Registering with the state boiler and pressure vessel department . Operating at pressures below the maximum allowable working pressure.

Quiz Questions: 

Quiz Questions 1 What pressure vessel test or tests are considered surface tests? A Ultrasound and X-ray. B Visual only C Liquid Penetration Only D Visual, Magnetic, and Liquid 2 A Boiler is considered a Pressure Vessel? T or F 3 weld seams are the least looked at item when doing visual inspection? T or F 4 What is a Pressure Hazard? A Human made disaster B Hypoxic condition C Chemical burn from leaking vessel D C only 5 What is the condition tor technique that Navy fighter pilots used to sober up before being catapulted off of a carrier? A Autopilot B Huffing on pure oxygen i.e. HYPEROXIA C That’s what co-pilots are for. D Pressure chamber with lots of coffee.