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.

Effects of Alloying Element

Dear Readers,

We often used alloy steel during our construction activity especially piping works in Power plants & Refineries. 

Alloys are usually stronger than pure metals, although they generally offer reduced electrical and thermal conductivity. Strength is the most important criterion by which many structural materials are judged. Therefore, alloys are used for engineering construction. The synergistic effect of alloying elements and heat treatment produces a tremendous variety of microstructures and properties. Important properties of Alloy Elements are as follows.

1. Carbon (C) : Carbon is a non-metallic element, It is a very strong austenitizer and increases the strength of steel.

2. Manganese (Mn) : Toughness

3. Chromium (Cr) : Hardness, strength, and Corrosion Resistance

4. Vanadium (V) : Strength and grain growth during heat treatment

5. Sulphur (S) : Residual Element

6. Phosphorous (P) : Residual Element

7. Silicon (Si) : < 0.3% Deoxidizer

8. Molybdenum (Mo) : 1% is for creep resistance. hardenability and strength, particularly at high temperatures.

9. Aluminum (Al) :  Grain refiner, < 0.008% deoxidizer + toughness

10. Nickel (Ni) : Low Temperature applications

11. Copper (Cu) : Used for weathering steels

12. Titanium (Ti) : Grain refiner, used as a micro-alloying element ( Strength and Toughness)

13. Niobium (Nb) : Grain refiner, used as a micro-alloying element ( Strength and Toughness)

14. Tungsten (W) : Stable carbides and refines grain size so as to increase hardness, particularly at high temperatures.

TORQUE TABLE

 Dear Readers,

Based on my previous posts you may familiar with grades of bolt, torque of bolt, torque calculations and slip factors. However it is a real challenge in construction industry to determine the torque for bolts. Technically it is based on the applications. Some times client mentioned in drawings or you may get it from technical specifications but most of the times both are missed out. Given below is an ideal chart. This is one of my rare collections. Hope it will be very useful to all engineers.

 

For More Details about Torque Click my Previous Post Torque

For More Details about Grade of Bolts Click my Previous Post Grade

For More Details about Torque Calculations Click Calculation

For More Details about Slip Factor/Nut Factor Click Nut Factor