Add pipe pressure damage

[Partmedia]

About the PR

This adds pipe pressure damage, which damages pipes when the internal pressure exceeds some threshold. In other words, pipes now explode from pressure.

Why / Balance

It doesn't make sense that pipes can hold an infinite amount of pressure without bursting, especially because canisters can explode. Most people agree that pipes should have an upper limit, so the rest of this is dedicated to discussing what that limit should actually be.

The pressure chosen in this PR is intended to demonstrate this code (see screenshots below), and not as the final number. For the final number, we turn to the community for feedback. Please contribute to the discussion by commenting below.

The number chosen in this PR is 1.5 × Atmospherics.MaxOutputPressure. This means that pressure pumps can never cause a pipe to burst, but misusing a volume pump will. This adds risk to using the volume pump. I didn't think to hard about this number since we're leaving this number to be determined by the community.

Technical details

Adds a pressure check to all pipe nodes in a PipeNet after each PipeNet Update(). Deal damage that scales exponentially with pressure.

Media

out-2023-10-11_15.20.01.mp4

• I have added screenshots/videos to this PR showcasing its changes ingame, or this PR does not require an ingame showcase

Changelog
🆑 notafet

• add: Gas pipes now burst at very high pressures.

[Partmedia]

I have a TEG setup that has a peak pressure of about 1600 kPa that's generating >250 kW to power the whole station, so this pressure limit is actually workable.

[TemporalOroboros]

This impl will break the entire pipenet at the same time. Can you make it so the damage is randomly spread out through the pipes so ruptures don't occur everywhere at once? I'm thinking of distro getting overpressurized and needing to replace all of distro.

[TemporalOroboros]

An additional thing could be making pipes just leak, instead of breaking entirely, when they are partially damaged. That way this doesn't repeatedly split a large pipenet.

[Partmedia]

Yes, it would be good to avoid a whole-distro explosion. What I could suggest is for me to randomize damage in this PR, and in the separate related PR #20928 make the pipes leak contents to prevent repeated splitting.

[Ilya246]

i'd say somewhere around 12 MPa for 1-steel pipes, and potentially have 2-steel pipes which are much more resistant

[deltanedas]

imo a new plasteel pipe should have higher resistance since currently engi has very little use for plasteel

[AJimmyU]

There's no pressure bypass valves or any form of automated pressure management, meaning this will exponentially increase the learning curve for a role that's already the hardest role to learn in the game. I think this is a good idea to implement once there's more tools available to regulate pressure and some form of automation is added.

However, currently it's a bad idea to implement and this implementation is very rudimentary.

As for what the pressure limit should be:

All pipes share the same volume, regardless of shape, which doesn't make sense in reality as a junction should logically have a higher volume than a straight pipe.

Current pipe volume: 200 L // 200 000 000 mm3
Current tile length, assumption: 1 meter // 1 000 mm
Allowable pipe pressure specification: https://www.engineeringtoolbox.com/astm-steel-pipes-working-pressure-d_775.html

Now to get the diameter of our pipes:

sqrt((volume / length) / pi) = r
sqrt(63661.977236758134307553505349006) = r
r = 252
diameter = 504

Now the only question remains, how thick are the pipe walls? This is represented by "schedule" in the specification table.

What happens to gas from ruptured pipe(s)? It should blow into environment at place of rupture, proportionate amount to the amount required to lower pipe pressure below damage threshold.

What kind of pipes can burst?

Can connectors burst?

Can pumps burst? If not, you know that players will just replace all pipes with pumps.

Can valves/filters/mixers burst? If not, players will just replace all pipes with these.

Can injectors/vents burst?

Can canisters burst?

Can machines such as a thermomachine burst? Why yes and why not?

How do you identify a damaged pipe?

How do you repair a damaged pipe?

Can you reference a design document for atmospherics?

[moonheart08]

There's no pressure bypass valves or any form of automated pressure management, meaning this will exponentially increase the learning curve for a role that's already the hardest role to learn in the game. I think this is a good idea to implement once there's more tools available to regulate pressure and some form of automation is added.

However, currently it's a bad idea to implement and this implementation is very rudimentary.

As for what the pressure limit should be:

All pipes share the same volume, regardless of shape, which doesn't make sense in reality as a junction should logically have a higher volume than a straight pipe.

Current pipe volume: 200 L // 200 000 000 mm3 Current tile length, assumption: 1 meter // 1 000 mm Allowable pipe pressure specification: https://www.engineeringtoolbox.com/astm-steel-pipes-working-pressure-d_775.html

Now to get the diameter of our pipes:

sqrt((volume / length) / pi) = r
sqrt(63661.977236758134307553505349006) = r
r = 252
diameter = 504

Now the only question remains, how thick are the pipe walls? This is represented by "schedule" in the specification table.

What happens to gas from ruptured pipe(s)? It should blow into environment at place of rupture, proportionate amount to the amount required to lower pipe pressure below damage threshold.

What kind of pipes can burst?

Can connectors burst?

Can pumps burst? If not, you know that players will just replace all pipes with pumps.

Can valves/filters/mixers burst? If not, players will just replace all pipes with these.

Can injectors/vents burst?

Can canisters burst?

Can machines such as a thermomachine burst? Why yes and why not?

How do you identify a damaged pipe?

How do you repair a damaged pipe?

Can you reference a design document for atmospherics?

this role barely needs pressures high enough to cause pipes to burst, this is fine as is and we don't need perfect realism (see also pipenets are a single giant gasmix as currently implemented, gas moves instantly inside of them, so trying to account for stuff like slight volume differences or exact pipe thickness with realistic values is small potatoes)

I'm not making the PR author fill out ur questionnaire, sorry.

[qwerltaz]

The threshold probably shouldn't be below 9Mpa to not make vol pumps useless. I think being able to utilize the vol pump's max outlet pressure is a feature, not misuse. And plasteel pipes could be made to withstand higher pressures than that for more specific applications.

It sounds good to have rupturing also apply to mixers, filters, pumps, etc. maybe vents too.

Randomized damage sounds like a good solution.

[AJimmyU]

I'm not making the PR author fill out ur questionnaire, sorry.

I see, so all the edge cases I listed are not relevant? You realize that as is, this will be completely ignored by clever usage of pipes and devices as I mentioned. but you're free to assume it's a "questionnaire".

[AJimmyU]

especially because canisters can explode

Canisters currently CANNOT explode.

[daerSeebaer]

Concerning some of @AJimmyU s concerns:

• Anything that can not replace a pipe (vents, scrubbers, canisters, thermomachines,...) can IMO remain immune to pressure damage to not make this even more complicated than it already is.
• filters, mixers, pumps etc. can also remain immune to pressure damage IMO since they already are susceptible to over-pressure in so far as they simply stop working. But I agree that passive gates and valves should be affected somehow.

There's no pressure bypass valves or any form of automated pressure management

• Atmos can build automatic overpressure release setups with pneumatic valves. This is a "hidden" mechanic since they are not mapped anywhere AFAIK, they are not explained in the Guidebook and are not part of any of the common Atmos setups. But they exist and can fulfill exactly that role.

As far as damage identification, effect and repairs go, that is explained and handled in #20928 .

Personal opinion: I'm also pro pressure damage, but would keep it from destroying the pipe and just make it leak.
Implementation suggestion: Check that pressure damage will never push the pipe to 100 damage, and maybe even stop damaging a pipe node entirely if it is already ruptured and leaking.
An example for leak code can be found in the volumetric pump since that can also leak.

[Cheackraze]

There's no pressure bypass valves or any form of automated pressure management, meaning this will exponentially increase the learning curve for a role that's already the hardest role to learn in the game. I think this is a good idea to implement once there's more tools available to regulate pressure and some form of automation is added.

However, currently it's a bad idea to implement and this implementation is very rudimentary.

As for what the pressure limit should be:

All pipes share the same volume, regardless of shape, which doesn't make sense in reality as a junction should logically have a higher volume than a straight pipe.

Current pipe volume: 200 L // 200 000 000 mm3 Current tile length, assumption: 1 meter // 1 000 mm Allowable pipe pressure specification: https://www.engineeringtoolbox.com/astm-steel-pipes-working-pressure-d_775.html

Now to get the diameter of our pipes:

sqrt((volume / length) / pi) = r
sqrt(63661.977236758134307553505349006) = r
r = 252
diameter = 504

Now the only question remains, how thick are the pipe walls? This is represented by "schedule" in the specification table.

What happens to gas from ruptured pipe(s)? It should blow into environment at place of rupture, proportionate amount to the amount required to lower pipe pressure below damage threshold.

What kind of pipes can burst?

Can connectors burst?

Can pumps burst? If not, you know that players will just replace all pipes with pumps.

Can valves/filters/mixers burst? If not, players will just replace all pipes with these.

Can injectors/vents burst?

Can canisters burst?

Can machines such as a thermomachine burst? Why yes and why not?

How do you identify a damaged pipe?

How do you repair a damaged pipe?

Can you reference a design document for atmospherics?

Some of these I had concerns about as well. When doing a burn for gas synthesis, how is the gas then handled? Once it's above a certain temp/pressure, the only way we have of affecting these variables is inside of pipes. The gas has to enter a pipe to get cooled, etc. And so, do passive vents take damage or explode?

Now we move on to a potential repair scenario: what does a broken pipe look like? Is it easy to find as an atmosian to fix? Stations can have miles of pipes for distro/waste, in the event one of the systems gets overpressurized how does an atmosian find the break? And is there any counter play? Any way to stop a leak or a break from occurring? Or any kind of timer or other signifier(doesn't break instantly, gives some kind of audio/visual cue that it's about to burst)

Not opposed to the idea fundamentally I'm just not certain this is an optimal implementation.

[TemporalOroboros]

Re: Burn chambers
This probably needs to be based off of the difference in pressure between the inside of the pipe and the outside of the pipe, rather than just the pressure inside. That way the pipes inside of the burn chamber don't break as they are basically impossible to get to to repair.
Additionally, pipes located under walls/windows also probably shouldn't break for much the same reason.

[BasedUser]

making all pipes volume-leak would probably be a lot better, maybe merge gas tank explosion code but with different constants?

[Partmedia]

Responding to @AJimmyU :

All pipes share the same volume, regardless of shape, which doesn't make sense in reality as a junction should logically have a higher volume than a straight pipe.

Current pipe volume: 200 L // 200 000 000 mm3 Current tile length, assumption: 1 meter // 1 000 mm Allowable pipe pressure specification: https://www.engineeringtoolbox.com/astm-steel-pipes-working-pressure-d_775.html

I think there's some physics misunderstanding here. Pressure is force divided by area, so maximum pressure does not depend on volume (or length of pipe). Only the cross-section matters, as the linked article shows.

Now the only question remains, how thick are the pipe walls? This is represented by "schedule" in the specification table.

Your calculations suggest a 20" diamter pipe. If you look at the "STD" column, which is a reasonable assumption since NanoTrasen is cheap, the maximum allowable pressure per your linked article is 6337 kPa. Which happens to be very close to the number I proposed. So it sounds like you're fine with this number.

What happens to gas from ruptured pipe(s)? It should blow into environment at place of rupture, proportionate amount to the amount required to lower pipe pressure below damage threshold.

Unclear, please leave your thoughts in the related PR: #20928

What kind of pipes can burst?

Only straight, bent, T, and 4-way. We can adjust this as needed.

Can connectors burst?

No.

Can pumps burst? If not, you know that players will just replace all pipes with pumps.

No. And they won't because they require power and reduce flow rate. Of course we can make pumps burst if you want.

Can valves/filters/mixers burst? If not, players will just replace all pipes with these.

See above.

Can injectors/vents burst?

No.

Can canisters burst?

Yes. See "maxcap".

Can machines such as a thermomachine burst? Why yes and why not?

No. See above.

How do you identify a damaged pipe?

You can't. You're welcome to PR a pipe analyzer.

How do you repair a damaged pipe?

Depressurize it, unwrench it, and replace it with a new one.

Can you reference a design document for atmospherics?

What do you want to see there?

To respond to @Cheackraze : I understand your concerns. At the same time, there shouldn't be no limit whatsoever. I'm planning on updating the breakage to also not break the entire pipenet at the same time. These numbers are also defined in YAML (pipe breakage is disabled by default in code) so are easy to remove. It would help if you could suggest a specific number to increase the limit to. 10 MPa? 100 MPa? 100000000000000 MPa?

There have been suggestions for 10-12 MPa. The realism suggestion from above agrees with the 6.5 MPa I PR'd. I'm inclined to up the number to around the 10-12 MPa range and keep bursting behavior.

[deltanedas]

maxcaps explode tanks not canisters

[Partmedia]

It would also be trivial to add a sort of "weak pipe" that can burst first, to protect the rest of the pipes like distro.

As @daerSeebaer pneumatic valves can already function as over-pressure release valves.

If only one pipe bursts (instead of the whole pipenet bursting) I don't think leaking matters.

It sounds good to have rupturing also apply to mixers, filters, pumps, etc. maybe vents too.

This would only require YAML changes to add. Maybe we should flip this around and make pumps/filters/etc burst way before pipes do, so that pipenets are protected in a sense?

[deltanedas]

in a burn chamber passive vents wouldnt burst since its high pressure on inside and outside, probably fine to let them burst

also an issue with making pipes under walls immune is that it will be the new meta to just wall/window up everything to handle infinite pressure

[NancokPS2]

That sounds ok tbh, think of it as reinforcing the pipe, except it is very expensive and inconvenient.
So far from meta

[Cheackraze]

@Partmedia i concur, they shouldnt be magically immune, im just concerned about making burn chambers (the intended synthesis method for now) impossible to actually operate, or other unintended knock-on effects. I think that, the combination of 1 pipe section breaking + having that section then leak its contents to 'relieve' the pressure out of both sides would be more optimal. In this fashion, you not only have simply 1 pipe break and not the whole net, but the leaking of pressure means that the pipenets (now 2) themselves have an outlet for the resulting pressure (which may still be too high above the threshold, meaning simply a cascade of pipe failures)

[Cheackraze]

along with that however, the broken pipe sprite should be made much more high contrast and obvious to casual passers by (even non-atmosians should be able to spot a broken pipe IMO) and probably render above the floor tiles after they've broken

[Partmedia]

I think the algorithm going forward is going to randomly damage all pipes, then preferentially damage already damaged pipes so that in practice damage will get focused on one pipe, and then leaking out the gas after breakage to prevent cascading failures.

Alternatively, we might just decide to make pipes basically indestructible but instead make pumps/valves/filters/other things burst at high pressure.

[AJimmyU]

I think there's some physics misunderstanding here.

There's no misunderstanding, the chart takes pipe diameter and schedule, and tells you recommended max pressure. The calculation was to determine SS14 pipe diameter and compare it to the chart.

Yes. See "maxcap".

Again, CANISTERS CANNOT burst or explode or anything of the sort, and will at most leak all contents when destroyed by damage. A handheld TANK can rupture if a burn reaction occurs inside of it or extreme temperatures meet. Maxcap is referring to tanks, not canisters.

What do you want to see there?

More than 1 person deciding the fate of the whole system, such as was the case with radiators where only you got to decide. If there's a document to reference, then there can be consistency and an argument can be made. Any feature people add there's an immediate request for a design document when it's a larger feature, I don't see why atmospherics is an exception for this.

Of course we can make pumps burst if you want.

The thing is that if you do not make it burst, then some time later someone will decide that using pumps/valves in such a way is an exploit just like it was decided that stacking scrubbers is an exploit. So I'd prefer thinking ahead about the consequences of a pressure induced burst and how players will certainly try to bypass it.

[keronshb]

This will need some discussion as engineering is known for having a lot of volumes in pipes.
There were different tiers of pumps that different thresholds. They didn't blow up but they would seriously clog the works if they weren't upgraded. I feel that's the better change than allowing pipes to rupture.

Allowing pipes to rupture also adds a new way to grief - purposefully popping pipes to grief.

[keronshb]

Please also read the section titled "An Interlude on Realism".

I've read it. I know what you wrote but that doesn't really handwave what I have to say.

You look and see that the pipe is broken.

Considering some stations can be huge. How are these pipes found? What would be the main deciding factor to finding the pipe?

Is it the air alarm?
Could be a good start, but what if the pipe is broken somewhere in maint? What if maint is huge?
Would broken pipes that are under tiles surface themselves? If not, then Engineers/Atmos techs would have to spend a lot of time prying up floor tiles in hopes of finding the pipe thanks to the doafters on prying floors.

Gas Analyzer? There could be leftover atmos in the pipes.

Because those fixes & systems could drastically change how this interacts with the game.

If this PR was a psuedo-fix for people stacking pipes & devices, it becomes irrelevant & an annoyance for people who want to mix gases.

If pipe layering is in, it's one of many ways to get around the pressure limit.

[deltanedas]

t-rays exist

[keronshb]

t-rays exist

I'd like to at least see an example of what this would look like if they're not going to be layered above the tiles.

The sprite itself turns into a smaller, one direction, damaged pipe. It also doesn't show what was damaged.

You wouldn't recognize that a T or corner pipe would go there unless you knew what it looked like beforehand.

[deltanedas]

ok that definitely needs unique broken sprites for each kind of pipe yeah

[keronshb]

In addition to my previous comment -

What happens when a room is super heated due to a fire? Or what happens if fires are made to burn hotter in the future?

Assuming the scrubbers are there, how would atmos deal with removing super heated gas?

Wouldn't the pipes break due to the gas pressure being overwhelming?

Wouldn't it cause a chain reaction of damage through the pipenet or does this exclusively stop at one pipe?

How would they safely attach a freezer to the pipes to cool the gas down?

How would they try to cool the raging fire down to be safe enough to go into the pipes? This would be exceptionally difficult without fireproof machinery. And how would this prevent spacing the room from being the better solution?

[deltanedas]

Wouldn't it cause a chain reaction of damage through the pipenet or does this exclusively stop at one pipe?

mappers could put fuse pipes under firelock doors to contain any kind of damage from fires

[Carolyn3114]

Wouldn't it cause a chain reaction of damage through the pipenet or does this exclusively stop at one pipe?

mappers could put fuse pipes under firelock doors to contain any kind of damage from fires

fuse pipe?

[deltanedas]

see:

Every new feature allows opportunities to grief. As we've discussed, there are plans to adjust the algorithm so that only one pipe (instead of the whole pipenet) bursts. There are also discussions to add weak pipes that act like fuses to protect the rest of the pipe net to limit the opportunity for griefing. And at the end of the day, there are many ways to grief, like bomb arrivals, smash windows to space, etc. Why hasn't every possibility for griefing been axed?

[keronshb]

Wouldn't it cause a chain reaction of damage through the pipenet or does this exclusively stop at one pipe?

mappers could put fuse pipes under firelock doors to contain any kind of damage from fires

Fuse pipes/weak pipes sounds like a bandaid.

Adding valves/pumps/etc would be a better idea overall and is a bit more engaging then having a failsafe pipe.

[deltanedas]

random shitters just turning off valves everywhere is bad and requires no effort

[Carolyn3114]

see:

Every new feature allows opportunities to grief. As we've discussed, there are plans to adjust the algorithm so that only one pipe (instead of the whole pipenet) bursts. There are also discussions to add weak pipes that act like fuses to protect the rest of the pipe net to limit the opportunity for griefing. And at the end of the day, there are many ways to grief, like bomb arrivals, smash windows to space, etc. Why hasn't every possibility for griefing been axed?

I mean this still removes the ability to get rid of hot rooms without just spacing them, makes scrubbers even more useless when siphoning or trying to get temperature back to normal

[Carolyn3114]

makes plasma floods more deadly, and makes the air lost impossible to get back because it's too hot and pressurized

[deltanedas]

I mean this still removes the ability to get rid of hot rooms without just spacing them

its already very slow to use a freezer, the way to remove hot air was always to space it

[keronshb]

random shitters just turning off valves everywhere is bad and requires no effort

Having weak pipes is also a low effort meme.
Valves at least introduce more gameplay.

Maybe also a way to direct it so it can detonate under a certain condition or a blow off valve?

I mean this still removes the ability to get rid of hot rooms without just spacing them

its already very slow to use a freezer, the way to remove hot air was always to space it

Spacing has been a meme for awhile now. I don't see how exploding pipes would help it.

[Carolyn3114]

I mean this still removes the ability to get rid of hot rooms without just spacing them

its already very slow to use a freezer, the way to remove hot air was always to space it

it certainly doesn't feel intended, especially with how emergency siphon exists for scrubbers. And when gas miners are removed, this is just going to be annoying for preserving that hot gas.

[keronshb]

random shitters just turning off valves everywhere is bad and requires no effort

Admin issue, then.

[deltanedas]

with unwrenching you can be caught in the act by players an admins since it takes a few seconds and is very audible, with just turning valves off you have to be really looking for it or camping logs for non atmos toggling valves which is bad too

[NancokPS2]

ID locked valves like air alarms?

[keronshb]

ID locked valves like air alarms?

That's a bit too hugboxy but an idea is potentially putting these valves in the already id-locked maint closets.

[ashkitten]

along with that however, the broken pipe sprite should be made much more high contrast and obvious to casual passers by (even non-atmosians should be able to spot a broken pipe IMO) and probably render above the floor tiles after they've broken

an exploding pipe should fling any floor tiles around it away due to the escaping pressure

[keronshb]

An update for this since discussion hasn't been active for a bit.

Potential issues with this:

• It's difficult to find where pipes burst currently
• This would make fighting fires much harder if scrubbers (floor) kept bursting pipes when trying to scrub super hot contaminates from a fire. Conversely this would also add to the issue of "just space a tile lmao"

Solutions:

• Pipes bursting should leave behind a pipe in the shape/direction of the burst pipe
• Tile should be removed so people know where the pipe burst in the underplating
• A better way of repairing/making pipes needs to be added (Rapid Pipe Device ported from SS13, ideally) before this is implemented
• There should be a way to track where the pipes burst (like a pipenet computer similar to the new powernet)
• Manual Valve pipes (non ID locked) should be added to atmos closets to prevent other pipes in the node from bursting

Personally I do not see pipe bursting from temperature/pressure being good for the game, but the solutions would at least make it more manageable.

[Ilya246]

yeah, i think we should implement the power monitor but for pipes before doing this
though nevermind, i don't see a situation where you would need to use such a monitor to spot a pressure/temperature-leak

[keronshb]

yeah, i think we should implement the power monitor but for pipes before doing this though nevermind, i don't see a situation where you would need to use such a monitor to spot a pressure/temperature-leak

Mostly it would be due to either the pipe being damaged somehow (someone broke/unwrenched a pipe, or a bomb dislodged it, etc) OR because fire got too hot & the waste (scrubbers) pull in too much hot/pressurized gas (CO2, plasma, oxygen, etc), which causes a pipe (or more) to burst.

EDIT: The first case (broke/unwrench) does become a bit more overbearing like suit sensors. If there's an engineer or an AI that's overly zealous & looking at the pipenet consistently for changes they could spot it in an instant. Which would prove to be an issue for antags trying to set something up stealthily.

[chromiumboy]

yeah, i think we should implement the power monitor but for pipes before doing this though nevermind, i don't see a situation where you would need to use such a monitor to spot a pressure/temperature-leak

You could have pipes on the monitor flash different colors for being over temp / over pressure / or burst pretty easily. The biggest issue is that with stacking it could get very confusing to follow the pipes. Pipe stacking should either be removed or converted to the tri-layer pipe layout system first, probably

[chromiumboy]

EDIT: The first case (broke/unwrench) does become a bit more overbearing like suit sensors. If there's an engineer or an AI that's overly zealous & looking at the pipenet consistently for changes they could spot it in an instant. Which would prove to be an issue for antags trying to set something up stealthily.

Isn't that the counter play for the crew though? You need to spot the damage early if you want the crew to be able to intervene before the problem gets out of hand

[Partmedia]

As we discussed and agreed, the game isn't quite ready for this, although we agree that it would be okay after implementing the pipe monitor. Let's close this for now and re-open with the same code when we are ready.

[keronshb]

yeah, i think we should implement the power monitor but for pipes before doing this though nevermind, i don't see a situation where you would need to use such a monitor to spot a pressure/temperature-leak

You could have pipes on the monitor flash different colors for being over temp / over pressure / or burst pretty easily. The biggest issue is that with stacking it could get very confusing to follow the pipes. Pipe stacking should either be removed or converted to the tri-layer pipe layout system first, probably

stack removing & introducing 3 layered piping and the RPD would be ideal before implementing for sure.

Isn't that the counter play for the crew though? You need to spot the damage early if you want the crew to be able to intervene before the problem gets out of hand

Kinda? It introduces counterplay but it also introduces a hard counter, which isn't as desirable.

[K-Dynamic]

Pipes need more obvious signs of incoming damage like shuddering in place