Compressed Gas Cylinders Safety

Dear Readers,

Industrial, manufacturing, repair shops, fabrication shops and construction operations require the use of compressed gases for a variety of different operations. Compressed gases present a unique hazard. Depending on the gas, there is a potential for simultaneous exposure to both mechanical and chemical hazards. 

Hazards include

• Fire & Explosion

• Missile hazard from broken cylinder heads

• Frostbite or gas injection under skin

• Impact from falling cylinders

• Poisoning     

• Asphyxiation     

• Over exposure 

Main Causes are inadequate training and supervision, poor installation, poor maintenance, poor storage, faulty equipment etc. 

We shall ensure at most safe precautions to create safe working environment to eliminate the risk of injury due to the compressed gas cylinders. The smart safety rules and controls are as follows.

• Inspect cylinders, regulators, flash back arrestors, hoses for damage and as per the standards before each use. Check cylinder & gas identification

• Use a cart/wheeled trolley or other secure means for moving - never carry or roll gas cylinders

• Grease or oils in areas where compressed oxygen is used can cause fire or explosion

• Use non-sparking tools for flammable gases

• Secure cylinders at work areas. Installation of caps on all cylinders

• Never refill or attempt to repair a gas cylinder

• Move leaking cylinders out of the offices/work areas – then vent all remaining gas.  Mark damaged cylinders “Damaged. Do not Use”

• Engineering controls such as gas cylinder storage areas, leak monitors, fume hoods, ventilation systems, sprinkler systems 

• Administrative controls such as inspections, training, audits, signage & labels, identification of authorized employees, safe operating procedures

• Proper personal protective equipment use

Personnel working with the compressed gas cylinders must be aware of the risks and follow safe work practices. Please take note on the identification of Hazards, required safety control measures, and communicate the information to the entire site crew.

Purpose of Admixtures

Dear Readers,

In continuation with Admixtures article, let us understand the functions

Functions of Admixtures

Concrete admixtures have various functions and they are as follows:

(a) To  increase  the rate  of strength development at early ages – calcium chloride is the most widely  used accelerator,                              

(b) To retard the initial setting time while pumping concrete over a long distance,

(c) To  increase the workability without changing the water content – pozzolana such as fly ash is used,

(d) To increase the strength,

(e) To  increase  the  resistance  to  freezing  and  thawing  – vinyl  resin  is  an  air entrainment admixture which is used for this purpose,

(f) To decrease heat evolution,

(g) To increase water tightness,

(h) To decrease capillary flow of water, and

(i) To decrease rate of bleeding and segregation. 

Chemical admixtures are various types and they are:

(a) Accelerating admixture – A substance that increases the rate of hydration of hydraulic cement, reduces the setting time, or in other words, increases the rate of strength development.

(b) Retarding admixture – A substance which delays the setting time of cement paste.

(c)   Water – reducing admixture – A substance which either increases the workability of freshly mixed mortar or concrete without increasing water-cement ratio or maintains workability with reduced water-cement ratio.

(d) Air – entraining admixture – A substance that causes air to entrap/Cd in the form of tiny bubbles in mortar or concrete during mixing to increase its workability and resistance to freezing and thawing.

(e)  Super plasticizing admixture   – A   substance that has very high workability with a large decrease in water content (at least) for a given workability. High range water reducing admixture (HRWRA) is also referred to as a superplasticizer.

To Know more about concrete admixtures click Here

Difference Between Sheet and Plate

Dear Readers,

We often used both Sheets and Plates in construction Industry. Let us see the difference between sheet and plate.

Sheet metal and plate metal are different forms of steel. The most notable difference between plate and sheet metal is the thickness of the products. Plate metal is thicker when compared to sheet metal.

Sheet metal is produced on an industrial scale by applying rolling, processing and drying techniques. Eventually it is the process of rolling that will decide whether a particular metal will be classified as sheet or plate. Rolling metal adds pressure which determines the overall thickness of the metal. If the metal is rolled thin then it is considered to be sheet and if it is thick then the metal can be classified as plate.

Sheet metal is made from steel and it is a metal that has thickness less than 6mm.

The only difference between sheet and plate steel is the gauge (thickness) of the metal. They both have very different uses, depending on the varying durability and weight requirements for different projects.

Types of Cement

Dear Readers,

As you are well aware that without Cement modern infrastructure is not possible or even unimaginable now. Cement is a critical component in the construction of buildings, roads and other brick-and-motor creations and it plays vital role in construction Industry. Cement is a grey colored powder that resembles ash in texture. It is a binding substance that is used to harden and set two materials, typical bricks or rocks together. Before using it, cement is mixed with water and other materials in varying ratios and placed between two substances as “glue”. 

It’s time to learn about the many types of cement available in the market to cater to different construction purposes. Cements are broadly classified into two categories – Hydraulic and Non-Hydraulic, depending on how they react to the presence of water.

Hydraulic Cement: This cement gets hardened in a very short span and are widely used in construction industry for saving time and effort.

Non-Hydraulic Cement: They have a very long setting period and can only work in dry conditions. Non-hydraulic is not practical for commercial constructions, as they cannot be used in sites that are open to weather challenges.

Selection of cement based on suitability for different concrete construction is important for durability considerations of structures. Thus, making wise choice of cement type for specific construction site that prevents structure from deteriorating and saves much repair and rehabilitation cost later. 

A wide variety of cement types are available in market, which are suitable for use under certain conditions due to its unique properties. They are as follows.

    1. Ordinary Portland cement (OPC)

    2. Portland pozzolana cement (PPC)

    3. Rapid hardening Portland cement (RHPC)

    4. Low Heat Portland Cement (LHPC)

    5. Portland Slag Cement (PSC)

    6. Sulphate-resisting Portland Cement (SRPC)

    7. Hydrophobic Portland Cement (HPC)

Other Types of cements are based on its either unique property or its application.

    1. High Alumina Cement

    2. Quick-setting Cement

    3. White Cement

    4. Coloured Cement

    5. Air Entraining Cement

    6. Expansive Cement

    7. Extra rapid hardening cement

    8. Super sulphated cement

    9. Oil-well Cement

    10. Ultra-high strength concrete (UHSC)

Ultra-high strength concrete (UHSC) is the latest spectacular development in the domain of Portland cement-based materials.

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Concrete Admixtures

 Dear Readers,

Concrete is widely used in civil engineering and construction. In the concrete mixing process or before the concrete mixing can make the concrete hardening, mixing better materials, called concrete admixtures.

Various types of admixtures are used in concrete to enhance the performance of concrete. Concrete admixture is defined as the material other than the aggregate, water and cement added to the concrete. Admixtures are artificial or natural, and it may be added to the concrete mix, just before or during the mixing, to change one or more properties of the concrete in the plastic or hardened state as required in our structure. 

The successful use of admixtures depends on the proper combination of ingredients and concrete. Most admixtures are supplied in ready-to-use liquid form and are added to the concrete at the factory or construction site. Some additives such as pigments, extenders, and pumping agent, etc., used only in extremely small amounts, generally from the vessel manually pre-measured ingredients.

Types and Functions of admixtures are as Follows.

There are two types of admixtures:

Mineral admixtures 

Chemical admixtures

(1)    Mineral admixtures 

Followings are the types of Mineral admixture:

Fly ash

Silica fume

Ground granulated blast furnace slag

Rice husk ash

(2)    Chemical admixtures 

Chemical admixtures are various types, and they are:

Accelerating admixture

Retarding admixture

Water – reducing admixture

Air – entraining admixture

Super plasticizing admixture

Special Admixtures based on the application

Pozzolanic Admixtures

Damp-proofing Admixtures

Gas forming Admixtures

Air detraining Admixtures

Alkali Aggregate Expansion Inhibiting Admixtures

Anti-washout Admixtures

Grouting Admixtures

Corrosion Inhibiting Admixtures

Fungicidal, Germicidal, Insecticidal Admixtures

Coloring Admixtures Bonding Admixtures

IP RATING

 Dear Readers,

It is Informed to you due to work load and personnel reasons, self could not be posted any Articles in past five months. I am really very sorry. Let us go to the post.

As you may aware that Electric and electronic equipment’s deteriorate or malfunction when water or dust enters to the device. The IEC has developed the ingress protection (IP) ratings, which grade the resistance of an enclosure against the intrusion of dust or liquids.

In this article, we are going to discuss the international rating system that classifies devices for different environmental conditions. That rating system is called the Ingress Protection or IP rating as it is commonly referred to. Sometimes also interpreted as International Protection Rating.

An IP rating is usually a two-digit grading system that’s applied to the enclosure of a mechanical or electrical item. First digit for solids and second digit for Liquids. Occasionally followed by a letter denoting specific materials, hazards or testing scenarios. an additional letter may be appended to the end of an IP rating.

The first characteristic numeral designates the degree of protection of persons against the contact with live or moving parts inside the enclosure, and machines against ingress of solid foreign bodies. The first digit will be a number between 0-6.

The second digit in an IP rating will be a number between 0-9, denoting the quality of resistance to moisture ingress at varying intensities, angles, depths and pressures of exposure or immersion.

Following table furnish the details of first and second characteristic numerals of standard degree of protection.

First characteristic numeral for degree of protection

Second characteristic numeral of standard degree of protection against harmful ingress of water 

Additional letter (optional) and Supplementary letter (optional) For the protection of personnel against access to hazardous parts with

Above the IP ratings are widely used throughout industry. You should not be confused with IP address or Intellectual property.