What is Steam Hammer?

A few things that can go very wrong when you put steam in a pipe...

Last month we talked about the damaging effects of water hammer, but there’s another state of H2O equally if not more dangerous when put in pipes. Today on Practical Engineering we’re talking about steam hammer and differential shock.



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This video was sponsored by Skillshare.

[Dustinmikl]

As a boiler operator I want to thank you for providing one of the best and most dynamic demonstrations of steam hammer I've ever seen! Truly a beautiful piece of work!

[saqibmudabbar]

You are one of those inspiring teachers that teach their students not just what happens but how to really observe things. I’ll never look at pipes the same way again and will definitely not think of them as just pipes. Absolutely fantastic.

[JeffGreenNV]

My son (who wants to be a mechanical engineer) watch these videos together, because you have a great method of presentation with lots of functional information compressed into a concise easy to understand format. Thank you so very much.

[aliasanon]

Excellent video. I'm actually a boiler operator, and I've seen the damage water can do once you put 170 tonnes of steam behind it. We recently had a catastrophic failure of a steam turbine after attempting to warm the steam lines without any drains open to allow the condensate to drain.
Luckily no one was around at the time and no one was hurt.
Steam is a very scary force to work with.

[MrUnkownGuyAC]

This channel really blows my mind at how dangerous engineering can be if not applied or done correctly, even to the tiniest margin! This makes me really appreciate the architectures and the system inside them around me!

[cdnpont]

One of our biggest process issues in our large integrated steel mill is how to deal with the steam condensate in complex systems. Sure, condensate is a useful "byproduct" as described, and you'd think it would be easy to drain it off anywhere required. Not so. In my division, we have a combination of old and new steam systems and quite frankly it seems nobody actually understands much. These HP steam systems scare the crap out of me... I've heard that big steam hammer crash, and in no way is it like water alone ! Super vid.

[paulmace]

Once saw a maintenance supervisor open a 6” steam valve wide open after a 2 day shutdown. Put 250 psi steam into the steam main instantaneously. Blew a 500 psi blind flange that was 500 ft away off of the end of the main. Never did find the bolts that were holding it on. It’s amazing what steam can do in the right hands and what it can destroy in the wrong ones.

[dsnodgrass]

I deal with this phenomenon every working night; bc my managers insist upon shutting the boilers I work with down at the end of their day shift. I come in at night (5 hrs. later) and have to fire them up again. Even though I have purge ports at the end of nearly every headpipe (and have them open); and have traps on every condensate return branch (before return mains), I get car-crash levels of hammer most nights, even starting on low fire. There's just not enough pass-way available to allow the condensate to clear. So it slams into end-flanges and traps; and I wince every time. That's how all my nights begin.

[stevemoore]

Your demonstrations are mind-blowing. Just an absolutely beautiful and awe inspiring visual.

[RobertMorgan]

4:30-5:00 I work in a water plant/distribution system, and as soon as the discussion turned to the condensate forming a seal in the pipe I'm going "yes, this is going to be great!". Whoosh, boom!
But yeah, it is very dangerous. We've had issues of our own with water and differential shock involving trapped air and pressure reducing valves.
We have a line feeding an online Ultraviolet Transmittance analyzer, which is fed directly off our high service pump main, a 14" pipe carrying 117psi, to a 1/2" line that ends at a pressure reducing valve that drops it to 35psi or less. We had an issue once of draining that large 14" piping to install a flow meter. Little did we know that drained the small line as well. When we bled as much air as possible out of the main, we missed that small line, and when the HS pump started the air hit the PRV, which air cannot operate, and was compressed to immense levels by the water rushing behind it, and the SCH80 piping failed spectacularly. One piece of a fitting was blown 46 feet across the room. Water is incompressible, but gasses are, and when they coexist in a sealed system bad things usually follow.

[mathtronic]

I work in an industry that uses water/liquid and steam flow every day, but as an operator of those systems, not an engineer. These visual demonstrations you make are extremely enlightening to see and help my understanding of the systems I work with. Thanks for making them!

[andrewbenjamin]

I rarely (if ever) comment on videos, but I love your videos man. Keep up the great work. Would love to know what else you have to share on steam infrastructure.

[TheSirGoreaxe]

Those slugs of water are dangerous. I never witnessed it myself, but I've heard about them slamming into the expansion bends on the main stream pipes and knocking off years of dust and paint, also making everyone in the plant soil them selves. The biggest fear of anyone in a steam plant is a main steam rupture, they are killers. Always always always bypass and warm up those steam pipes and ensure those steam traps are on service.

[AyeCarumba]

Reminds me of my own steam story. In the 1980’s, I spent a few nights in an apartment in Manhattan that apparently had steam heat. Boy the sounds that thing would make! It was like somebody was in the room with a hammer clanking on the radiator every once in a while. I don’t know how anybody slept, I don’t know how the system didn’t just break somewhere. 44 years later, still crystal memories of those nights!

[steventaylor]

Good job, I've been steaming high pressure plants for 43 years. Proper warm up and draining is key.

[CristiNeagu]

I wish the experimental rigs you build would take a more important role in the videos. This one was pretty good, but in other videos you spent what could possibly be hours building something, only to show a few seconds of video. I think it's a shame, because you put so much effort into building them.

[eblackbrook]

It's worth mentioning, that the partial vacuum formed by the steam condensing as it hits cold pipes is actually what drives the propagation of steam through the pipes, pulling the steam from the furnace towards the ends of the system (like radiators). This at least is true of low pressure steam heat systems in old homes, and I assume it applies to other applications also.

[kmlkmljkl]

Just today I watched a video on new york's steam system and now you upload this. interesting

[jeremy]

I can really see the improvement your channel has gone though in the past year of following your content. I love the video and the work your doing, keep it up!

[ripwolfe]

Aside from your amazing science/engineering instruction, I'm super impressed with your videography and definitely your speaking skills. Clear, concise, and you keep on point. I'm going to have to check out Skillshare myself for videography.