what is the minimum percentage of carbon required for

Acceptable and Dangerous Gas Levels in Confined Spaces

Jun 08, 2020 · Hydrogen sulfide has a PEL of 20 parts per million (PPM) and an LEL of 4.0%. Carbon monoxide has a PEL of 50 PPM and an LEL of 12.5%. Keep in mind that permissible exposure limits can vary by jurisdiction, so the PELs OSHA lists for hydrogen sulfide and carbon monoxide

Air entrainment and concrete - USDA

1 inch (25 millimetres) 5 ± 1.5 percent air 11 2 inches (38 millimetres) 4.5 ± 1.5 percent air 2 inches (51 millimetres) 4 ± 1.5 percent air 3 inches (76 millimetres) 3 ± 1.5 percent air a Normal weight aggregate concretes only. For lightweight aggregate concretes specify 7.5 ± 1.5 percent CHAPTER 11 COMPOSITE MATERIALS - Cartagena99Compared to S glass, E glass has higher percentages of SiO2 (65 percent versus 52 to 56 percent) and Al2O3 (25 percent versus 12 to 16 percent). Also, E glass contains about 10 percent MgO as an additional compound whereas S glass contains 16 to 25 percent CaO and 8 to 13 percent B2O3. S glass is both stronger and more costly than E glass.

Carbon Dioxide Detection and Indoor Air Quality Control

Apr 01, 2016 · Carbon dioxide levels and potential health problems are indicated below:250-350 ppm:background (normal) outdoor air level. 350-1,000 ppm:typical level found in Carbon Dioxide:The Gas of Life - HOME CFACTIn more everyday language, the 400 ppm of carbon dioxide now in our Earths atmosphere is 0.04 percent the equivalent of 40 cents out of one thousand dollars, or 1.4 inches on a football field. Thats an incredibly small amount. (The atmospheres oxygen concentration is equivalent to

Confined Spaces:Is 19.5 Percent Oxygen Really Safe?

Dec 01, 2009 · If we again subtract the contribution for water vapor and carbon dioxide, we will find that alveolar oxygen partial pressure is about 83 mm Hg vs. 110 mm Hg at sea level. However, at an oxygen level of 19.5 percent the level widely touted as "safe for entry" the oxygen partial pressure in the alveoli drops to about 74 mm Hg. Design of fire fighting systems with carbon dioxide Once the net volume is known, we proceed to determine the design concentration of carbon dioxide that is required for the type of flammable material involved. In

Fuels and Combustion - IIT Kanpur

In most of the combustion processes the required Oxygen is not supplied as pure Oxygen but is supplied as air. Air contains 21 mol percent O 2 and 79 mol percent of N 2. The minimum amount of air which supplies the required amount of oxygen for complete combustion of a INERTED FUEL TANK OXYGEN CONCENTRATION As can be seen in Figure 6, the minimum oxygen requirements for most hydrocarbons are within 1 percent of variation and are between 11 and 12 percent at one atmosphere and 80°F when inerted with N2. The inerting requirements decrease with increasing pressure and decreasing temperature as illustrated in Figure 7, Reference 5.

Indoor Air Quality:Carbon Monoxide and Carbon Dioxide

When frozen, it is dry ice. At concentrations of from 2,500 ppm to 5,000 ppm carbon dioxide can cause headaches. At extremely high levels of 100,000 ppm (10 percent) people lose consciousness in ten minutes, and at 200,000 ppm (20 percent) CO2 causes partial or complete closure of the glottis. Minimum Ventilation Rate - an overview ScienceDirect TopicsThe limit for carbon monoxide concentration is 30 ppm for an 8-hr average and 75 ppm for a 15-min average. The minimum supply air flow rate is 2.7 liter/s/m 2. This rate would require 9.72 air changes per hour per meter length of ceiling height.

Percentage of Argon in Mixed Shielding Gas Does Matter

As a side note, when using a mixed shielding gas for gas-shielded, flux-cored electrodes, generally the minimum percentage of argon to use with CO2 is 75%. As you decrease the percentage of argon in the mix below this level, you quickly start to lose the operator appeal benefits of the argon. SPECIFICATION FOR PRESSURE VESSEL PLATES, CARBON (B) For each reduction of 0.01 percentage point below the speci ed maximum for carbon, an increase of 0.06 percentage point above the speci ed maximum for manganese is permitted, up to a maximum of 1.50% by heat analysis and 1.60% by product analysis. (C) Grade 60 plates 1

STEEL CASTINGS HANDBOOK Supplement 8 High Alloy

Representative Minimum tensile tensile properties & toughness air cooled from requirements about 45 percent less than carbon steel but almost 60 percent greater than the CF alloy types. Electrical Depending on strength requirements, the alloy is tempered at 600°F (316°C) or more commonly in the range of 1100 to 1150°F (593 to 621°C Safety - What is %LEL / %UEL and PID and PPM? - Lower The ratio of fuel and oxygen that is required varies with each combustible gas or vapor. The minimum concentration of a particular combustible gas or vapor necessary to support its combustion in air is defined as the Lower Explosive Limit (LEL) for that gas. Below this level, the mixture is too "lean" to burn.

Solved:What Is The Minimum Chromium Concentration

What is the minimum chromium concentration required to make a stainless steel corrosion resistant? 1.00 wt% Cr 5.00 wt% Cr 6.50 wt% Cr 10.0 wt% Cr 11.00 wt% Cr 13.00 wt% Cr Standard Specication for Steel Bars, Carbon and Alloy Steel Bars, Carbon and Alloy, Hot-Wrought, General minimum thickness up to 6 in. in width; and 0.230 in. in minimum thickness for over 6 to 8 in. in width, inclusive [over element to a standard steel, the percentage of lead is reported as 0.15 to 0.35 incl, which is

limiting oxygen concentration and ammability limits of

This paper presents data on the limiting (minimum) oxygen concentration (LOC), in the presence of added N. 2, of methane (CH. 4), propane (C. 3. H. 8), ethylene (C. 2. H. 4), carbon monoxide (CO), and hydrogen (H. 2), and some of their binary mixtures. It also addresses the issue of the ammable concentration (ammability) limits of these What is carbon steel? Carbon range and carbon steel definitionCarbon steel is steel in which the main interstitial alloying constituent is carbon in the range of 0.122.0%.The American Iron and Steel Institute (AISI) defines carbon steel as the following:Steel is considered to be carbon steel when no minimum content is specified or required for chromium, cobalt, molybdenum, nickel, niobium, titanium, tungsten, vanadium or zirconium, or any other

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