Steam boilers Q/A

[rnoel]

Need to brush up on steam boiler basics, possible interviews on the horizon. Been a little while since I’ve done start-up, checks etc, please add any omitted steps in start sequence. This would be at least 200HP, High or Low psi fire tube boilers. Boiler off –line on stand-by, but full off make up water ready to fire up. 1) Check all safeties or made e.g. low water, gas pressure, etc and check pressure setting on controller 2) Initiate feed pumps, and assure venting open on boiler to release air. 2) Once column at proper level start blower purge via control panel. 3) Initiate burner light off. 4) Once up to enough psi, perform low water safety check via column blow, to drop burner to assure safety function. 5) Monitor boiler to reach operating pressure via psi gauge and stabilized. 6) Quick bottom blow. 7) Perform water chemistry for boiler. I know I likely missed some procedures, please reply/add any start up sequence steps. Steam gurus wanted.

[GA FRANK]

Your plan sounds good to me, just bring it up slowly.

[lafittejdubb]

I'm not a steam guru by any means but Boiler Operator's Workbooks would probably be more helpful to you since you already have a strong background. Workbooks, really hit on the safety settings and reinforce the fundamentals so you don't miss any of those q's which might be an automatic disqualifier.
Sorry, it's been a long time since I've worked on boilers so that's the best I can provide.

[flange]

on a cold start, typically you want to keep it in low fire hold to warm it up slowly. nothing like letting a medium sized burner go to high fire on a cold casting. if multiple boiler setup, you may need to keep it isolated until you get near operating presure of other boilers.

[rnoel]

Thanks for additional info guys..

[JayATS]

The boilers we have here in this plant all have a fire eye control that will not allow the burners to run 100% unless there is 40# steam pressure present. I still like to bring them up manually as to regulate how fast they come up. We have daily, monthly and annual PMs for our boilers. Daily would consist of low water alarm checks and bottom blowdowns, we have a in house chemest to take water samples and add chemicals needed. Monthly we do burner fail alarm test and check for gas leaking by the modulating gas valves. The yearly pm is to tear down the boiler punch the tubes and look for possible leaks in the tubes, squeeze test the boiler if nessesary. Replacing all seals along the way.

[xformer]

and assure venting open on boiler to release :

I always leave burner on low fire hold and leave a top vent open untill it just starts to make steam. this assures that the water is de-airated.

[xformer]

The yearly pm is to tear down the boiler punch the tubes and look for possible leaks in the tubes, squeeze test the boiler if nessesary. Replacing all seals along the way.

Just to add a few notables- remove all cross plugs and siphon tubes and inspect for blockage, inspect refractory and repair/washcoat as needed, remove handhole covers and inspect-especially mudlegs. remove LWC and clean bowl.

[engineerbrian]

Safeties are key for obvious reasons, but as others mentioned so is a slow warm up. Dont forget, safeties need to be checked on a regular basis, not just at start up!

Heres how i warm up a boiler

1) Open vent on boiler.
2) Put burner control in manual, low fire.
3) Start boiler for 1 minute
4) Let boiler stand for 15 minutes
5) Start boiler for 2 minutes
6) Let boiler stand for 15 minutes
7) Start boiler for 3 minutes
8) Continue this process adding a minute to the run time for each sequence until steam steadily comes out of your vent and you start building steam pressure (not much just a few pounds)
9) Close vent
10) Continue to operate boiler in manual low fire until a full head of head steam is built up in the boiler.

Hope this helps!