Hazards of Steam

Steam is the utility most observed by people passing by refineries and chemical plants. White clouds of escaping steam are seen all over a plant because steam can be used for so many things. Steam  

After vessels that operate at atmospheric pressure or above have been purged with steam prior to startup, fuel gas or another suitable gas must be backed (pumped) into the vessel when purging is completed. This is done to displace the steam, which if left inside, will condense and form a vacuum. If the vessel is left full of steam with valves closed, condensation can produce a vacuum great enough to collapse the vessel. Also, since valves frequently do not close tightly, the vacuum caused by condensing steam may draw in air. This creates a flammability hazard when hydrocarbons are introduced into the equipment. 

Steam heating of blocked in exchangers or steam tracing of pipe or other equipment completely full of liquid can result in dangerously high pressures if a pressure relief valve is not provided. Liquids expand when heated. If a full vessel is blocked in and heated, 

Electrocutions kill an average of 143 construction workers each year. Data from 1992 through 2003 indicates electrical workers suffered the highest number of electrocutions per year, 34 percent of the total deaths caused by electrocution ( Alarming statistics, by D. Bremer, 2007, Electrical Contractor). Direct death from electrical shock results from ventricular fibrillation, paralysis of the respiratory center, or a combination of the two. Electricity can be hazardous to the process employees in a variety of forms. They are  

---

Volatile liquid eontaminants ean be removed from PPE or equipment by evaporation followed by a water rinse. Evaporation of volatile liquids ean be enhaneed by using steam jets. With any evaporation or vaporization proeess, eare should be taken to prevent worker inhalation of vaporized ehemieals. And, of eourse, the physieal hazards of steam need to be taken into eonsideration along with proteetion needed to eontrol any splatter of liquid or debris. Regulations pertinent to air emissions must also be taken into eonsideration. 

I am delighted to say that BP HSE Shared Resources has rejuvenated the safety booklets that were initially developed by Standard Oil. In 2003, the series was released and entitled, Sharing the Experience. [2] The 2003 edition of Hazards of Water (booklet one) is superb. It was originally published in 1955 and has been steadily improved over the past five decades. The companion booklet, Hazards of Steam, (booklet six) is excellent and has... 

The 1984 AMOCO Oil hardcover book is an accumulation of nine individual, previously published booklets. The booklets are each chapters in the 1984 edition with titles including The Hazards of Water, The Hazards of Air, Safe Furnace Firing, Safe Ups and Downs for Refinery Units, The Hazards of Steam, and other fundamentals needed by operators, supervisors, and engineers. 

The Hazards of Steam (2004) [3] is an excellent companion and has been around for decades. It was first published in 1963. Each booklet is full of hard-learned lessons, with a view from inside the fence hne of refineries and chemical plants. The newest editions of these booklets are now available from the IChemE. They are now sprinkled with a generous amount of recent color photos and vivid color illustrations. 

Hazards of steam, BP process safety series (Booklet 3), IChemE 2004. 

Process hazards Hazards of utilities Hazards of water Hazards of steam Hazards of ice Hazards of compressed gas Hazards of air Hazards of external events Hazards of equipment and instruments Hazards of piping, valves, and hoses... 

One of water s greatest hazards is the volumetric expansion (and corresponding pressure increase) that takes place when it is transformed into steam. For example, at its boiling point of 100°C water vapor occupies a volume 1,600 times that of the corresponding liquid. Many of the hazards of steam discussed below are so serious because of this very large volumetric expansion. 

The operating team as a whole had been aware of the well-known hazards of water hammer in steam mains. 

A hazard and operability study w as carried out during design, but flow of steam from the treatment vessel to the reactor was never considered as a possible deviation, perhaps because the team... 

Inspection by independent persons or bodies for safety purposes goes back to the middle of the nineteenth century. At that time, the focus of concern was the explosion of steam boilers, and this hazard was most prevalent in the textile industry. Consequently, a group of public-spirited individuals formed the Manchester Steam Users Association for the Prevention of Boiler Explosion. This body carried out boiler examinations and later added insurance as an inducement to the plant owners. By the beginning of the twentieth century steam and gas engines and electrical machines had been added, followed by lifts, cranes and hoisting machines. 

U.S. EPA defines boilers as enclosed devices that use controlled flame combustion to recover and export energy in the form of steam, heated fluid, or heated gases. A boiler comprises two main parts, the combustion chamber used to heat the hazardous waste and the tubes or pipes that hold the... 

In liquid phase aerobic oxidation of p-xylene in acetic acid to terephthalic acid, it is important to eliminate the inherent hazards of this fuel-air mixture. Effects of temperature, pressure and presence of steam on the explosive limits of the mixture have been studied. 

---