Boiler safety valves slight issue

Good day

I have just steamed my coal-fired stationary boiler for the first time which I have nearly completed fitting out. The boiler is more of a test boiler to try out engines, pumps, injecters etc...

I have built the boiler with a manifold with 2 spring safety valves and 1 dead weight one. The idea being to have the option if required to run on any pressure up to 70-80psi.

I pre-set the spring safety valves, one to about 70 and one to about 72 on a hydraulic pump. All was peaceful during steaming until the first one blew off; it would have been fine if it was just steam, but it picked up large amounts of water as well after being open for about 5 seconds. Not at all how I wanted it to happen. Being a coal-fired boiler it can take a while to calm the thing down. I have not yet built a damper and don't have a decent size engine to use some of the steam up yet so I am really just testing the valves.

During steaming, the water was round about the middle of the guage glass and the boiler was not over filled.

The bush into the boiler for the manifold is 1/4 40 and I have made a stainless male to male adapter which has allowed me to use the largest bore possible while keeping the strength.

Is this a problem anyone else hase had with safety valves picking up water during normal running?

I may end up gas or meths fireing the boiler so I can use inside so I would like to sort this problem out. I have routed out the bottem of base to take the steam pipes which pop up in the back corners of the base.

Looks nice, newly built boilers can have a tendency to 'prime', that is to eject water out with the steam through the safety valve, should settle dow with further use.

If you run on gas inside make sure you have a carbon monoxide alarm fitted and plenty of ventilation.

Roger

Edited By Rockingdodge on 28/12/2020 16:33:28

Thanks Roger

Ok, interesting, I will see how the next run goes.

Alvin

You need to blow it down till empty several times.

Adding more water will stop it blowing off.

Why is the adjustable valve the high pressure one? It will never work except below 70psi.

If your talking about the dead weight safety valve, just means the boiler can be set accurately to any pressure if for what ever reason that was required. The valve body for that one I have another which has no hole drilled, will sit in the real ones place most off the time and act as a plug.

"You need to blow it down till empty several times."

Is this just to ensure it is totally clean inside?

New boilers foam due to all the building residue