The Object of a safe start-up is:
(1) to get the water out of the line before steam is admitted,
(2) while admitting steam, do it slowly enough so condensate cannot accumulate faster than drains can remove it from the system.
(3) keep steam flow velocity low until the system is dry.
Do not rely on traps to remove condensate during start-up, they work too slow. 3500# of condensate will form in a matter of minutes during warm-up of 75 degree F cold piping to 325 degree F steam temperature. Failure to remove this condensate can result in waterhammer.
This procedure requires a steam foreman to supervise opening of the 10" steam valve at H-1 and five workers to man condensate drain stations at M.H.'s C-4, G-1, G-8, G-6 and G-3. (It does not account for other safety personnel that may be required by site safety procedures atop the Pit). All personnel shall have 2-way radios to communicate.
1. Clear the Manholes of non-essential personnel. No-one other than operators involved in the start-up shall be in the Manholes during start-up.
2. Open all drains on cold portion of steam main if not already open. Drain water. Leave drains open. All residual condensate must be drained before admitting steam. Report to foreman.
3. At hot side of gate valves isolating steam from cold section of main at H1, C4, and G1, open bleed drains sufficiently to blow out any residual condensate. Close when clear. Report.
WARNING: Condensate will be at 325 degree F and flashing to steam, wear protective clothing and ear protection.
4. With a foreman stationed at H1 in contact with men equipped with two-way radios stationed at C-4, and G-Line bleed drains , and with all cold side drains open, foreman shall "crack" open the H1 10" gate valve until steam flow is heard--approx. 1 to 1-1/2 turns of the hand wheel.
WARNING: The valve at H1 must not be opened if water is resting against the cold side of the valve. This will occur if H Line between C-4 and H-1 is operated with the H-1 gate valve closed. Do not allow system to be operated in this configuration. If you suspect system has been operated in this configuration, STOP.
5. Periodically open then close the hot side drain at H1 to allow condensate forming between H1 and C-4 to escape through drain until steam system is warmed to ~ 325 degree F. (Close drain to allow operator to hear radioed instructions.)
6. Operators at drain stations shall report status of condensate flow to foreman. Maintain watch until there is no more condensate escaping through drains with the steam. (Note, at the point that steam first appears at 212 degree F, only about 1/2 the condensate that will eventually form will have left the system. The system still has to go to 325 degree F!)
If you hear waterhammer, leave the pit. Radio the foreman.
Partially close drains as steam begins to forcefully eject from drains.
7. Foreman. With all drains admitting steam, and little if any water, valve may be opened another 1/2 turn or so if necessary to build steam pressure at end of line. Note--temperature cannot build unless line pressurizes. (But don't the steam valve it too much or it will fill the Manholes with steam where your men are observing the flow out the drains).
8. When flow from drains is pure, dry steam, and foreman senses pressure on valve has equalized, close all drains. Open the H-1 steam valve fully. Bleed the H-1 drain one more time.
Shut Down Procedure
1. Close H-1 10" steam valve.
2. Open drain valves at C-4 and G-1.
3. If water drains from either manhole, notify foreman.