ESP Air Leak Test, Boiler Duct Air Leak Test

If the facility hasn't got time to do it properly, where is it going to find the time from to put it right after it has gone wrong?

Nowadays these tests are not being done in some of the Projects by EXECUTION/ERECTION depts to save time. Why are you being bothered then. Let them find out the hard way after commissioning.

"What are the affects in operation of Boilers operation if the leaks are more?"

Overall efficiency of the boiler will suffer.

Duct and flue leaks reduce efficiency and cost money. The time to test for leaks is after the fabrication (diesel testing) and erection (smoke testing) of the equipment. Diesel testing is a bit messy but effective as diesel will leak through vey small perosity weld leaks. Smoke testing is difficult as you have to isolate each section of duct and apply a small pressure, perhaps 20 mbar. If the ducts are diesel tested during fabrication it is possible to insulate most of the duct leaving only field welded joints for smoke test. In this thread it is stated that much of the time no tests are done on-site and I suspect this is because it is late in the project and everyone is revved up to complete ASAP. Infrared testing can only be done during operation.

Dear Mr.csrao

The test referred by you is a must and compulsorily to be done. Question of Saving of Time is not the right argument. On the other hand, it is worth to conduct these test - even if it is delayed.

The bad effects of LEAKAGE in the duct are : 1. Insufficient air at the Furnace, since the leakage results in short-circuit of air flow, thus reducing the air quantity at the furnace. 2. Higher chances for incomplete combustion and formation of CO, thus Heat Loss. 3. Leaky air, will lower the Flue Gas Temp. and may fall below the DEW-POINT Temp. thus condensation of water will start and damage the ID Fan Impeller. 4. Due to leakage, Flue Gas Temp. will fall and reduce the Natural Draught available.

DHAYANANDHAN.S