Thursday, March 31, 2011

Furnace bridge wall

Bridge wall in a furnace is the section the radiation section ends and the convection section begins. The function of the bridge wall is to force the flue gas in a particular path and concurrently generate a pressure drop which affects the draft through the furnace as a whole. The temperature at that point is the bridge wall temperature.

Fine-tune your delayed coker

Nice article on delayed coker

Tuesday, March 29, 2011

Cold Differential Test Pressure - CDTP


It is an adjustment to the set pressure of the valve when it is being set, as it is not at process conditions. The correction can be due to backpressure and/or temperature fluctuations. It can be defined as

(set pressure - back pressure)*correction factor

Correction factor is supplied by manufacturer.

What is CDTP? Interesting stuff in this link. Cold Differential Test Pressure - Cheresources.com Community


Monday, March 21, 2011

2xAA to D-Size Cell Battery adapter / converter

This is a pretty cheap solution to run the cradle and swing. I can't stomach the fact that I paid $11.5 for 8 D-size batteries.

$2.76 - SoShine 2xAA to D-Size Cell Battery Converter Case (2-Pack) - Batteries: "2xAA to D-Size Cell Battery Converter"

Wednesday, March 16, 2011

Permissive, interlock - Difference

The PERMISSIVES, are some conditions that need to be satisfied before you can start the machine. For e.g. a compressor can be started only when there is sufficient suction pressure.

INTERLOCK: During the process, if a condition fails, interlocks are activated. For e.g. a pump shutdown interlock is activated when the level of drum goes low.

An interlock can also be a permissive, but the converse is not true. For the compressor example (in Permissives), if insufficient suction pressure is a permissive, the compressor will not shutdown, if there is insufficient suction pressure. It is just a condition for the system to start. But if insufficient suction pressure was an interlock, the system will shutdown, when ever the suction pressure goes below a fixed value. But once shutdown, all the permissives need to be satisfied before the system can start again.

More details here

P&ID acronyms

Lots of acronyms available in the link below

Tuesday, March 15, 2011

Will blackberry use wifi over 3G

Will blackberry use wifi over 3g

Yes, but you will have to make some modifications in the browser options.
1. Go to browser>menu>option>broser configuration>set it to hotspot broswer

2. Go back>general properties>and set it to hotspot broswer.

Thursday, March 3, 2011

Hot bolting

Hot bolting is a method of replacing the bolts on a live line. Normally done one bolt at a time. Hot bolting should be used only when there is no other reasonable choice.

The criteria typically followed is something like:
• The operating pressure must be less than 75% of the MAWP as allowed under ANSI B16.5 at the operating temp of the piping or process system to be hot bolted.
• The flange must have a minimum of 8 bolts
• The process temperature must be between 4°and 71° C.
• All flanges and associated system equipment must be adequately supported, i.e. no excessive vibration or pulsation.

Monitoring for hydrocarbons is also a must during the operation. Generally the procedure for hot bolting is the same sequence as for a tightening operation.
• The gasket area must not show signs of leakage. Piping, flanges, and bolts must not be severely corroded, i.e., to the point of affecting their integrity.
• Existing flange bolts/nuts must be tight and of the correct size and grade.

Credits to GregLamberson and other posters here

Tuesday, March 1, 2011

Side to side baffle trays

Side-to-side trays are trays that allow the liquid to splash from side to side. The decks can be sloped. Fouling potential of this tray is low, as with efficiency.




A very good article here