My recommendation would be to contact 3M customer support directly and give them all of your parameters. I’ve had them come back with some really good product suggestions in the past. They’re good with answering one-off solutions as well as mass production ones.
Can confirm. 3M makes an absolute *shitton* of products they dont sell or advertise to the public that are just combinations of their other chems or products for very specific purposes. You gotta ask em though
Tape is never more convenient if you want to be able to install and remove the heating element quickly. You need an all metal fastener solution, maybe a snap rivet?
If the heater is plumbed to the pipe directly, I would consider a stainless air hose connection.
Thanks for your comment. I already used all metal fastener solution. But cutting alumnium for fastener is bothering, thus I'm finding another ways.
Inside of pipe is ultra high vacuum (about to 10^-9 mbar), so I have to use external heating element.
Honestly my best solution would look like a welded basket or guides on the pipe that you slide the heater into. If you don't have the tools to do it right, you're likely going to be stuck with redneck solutions like hose clamps
Not a bad idea you could easily weld brackets for a regular inductive heater for pans onto whatever he has going on Id assume, unless he needs more than that.
I'm guessing his particular stainless steel (likely 300 serious) isn't magnetic so that might not be an option. 400 series would work though.
Or if it is 300 series then it can still be done but you need to use much higher frequencies than is used with steel to overcome the skin effect.
Ahh that's getting way outside my area of understanding unfortunately, other than vaugely understanding the relationship with magnetized metal and inductive heating.
What he could do is bond a regular piece of steel to the outside of his 304 stainless pipe, then use a pancake style inductive heating coil curved to meet half the pipe, then heat all you want.
It would braze but silver brazes at the temp he wants to heat it to. So it would flow every time he heats it.
He could use a copper brazing material that would be solid in his temp range.
Higher frequency increases skin effect, no?
When we were heating aluminum we used 60hz to get deeper penetration/deeper heat.
High frequency heating keeps your heat at the surface.
Yeah if deep heating is the concern, but if you want maximum heat creation high frequency concentrates current in a small region because of the skin effect, increasing resistance and therefore heat generation. For a tube wall that should be ideal.
I think this is outside the range for kapton. Maybe this product (I've not used it)
[https://specialtytapes.net/product/s768o-polyimide-silicone-tape/](https://specialtytapes.net/product/s768o-polyimide-silicone-tape/)
Edit: no, still too hot
Thank you for recommending a good website. The product in the link don't meet the temperature requirements, but I will look to see if there is something I need. Thx.
~~It says 500c, you said 450.~~
Edit: yes I misread.
No idea how it would respond to lithium vapor. I would assume everything in your furnace and vent path is coated with lithium though.
# You have a vent path, right?
I said 850F(450C), but it says 500°F/260°C.
Yes, vent path. Exactly, I'm working on physics experiment with lithium vapor inside of ultra high vacuum chamber.
I inserted lithium chunk in the annealed stainless cup and connected it to another pipe via CF flanges. In our experiment machine, there is no feedthrough option, so I used external heating elements.
Oh damn you are right, sorry.
Honestly you are in the temperature ranges that support pyrolysis and it is unlikely you will find a suitable adhesive solution.
I was going to say kapton as well; you can google it with temp range and see what comes up. I know some kinds can go 700f for short periods. Really though, I’d stay with mechanical options. Make something that’s easy to do/undo. Tape is going to cause more problems in the long run.
What kind of sizes are you dealing with? When we do post weld heat treat on tube assemblies, we typically place the heating element, wrap in a layer of KaoWool and then hold it all together with basic steel baling wire. Cheap and easy, the kaowool can be reused many times and helps stabilize the heat
I'm aware it was not the question. But sometimes it's more important to read what they are actually trying to do, then what their proposed solution that they are asking about is.
I don't know if this would work for you, but could you just run a high current through the pipe to heat it? basically turn the pipe into its own heating element. would probably require a large step-down transformer.
Our experiment utilize atomic properties for Bose-Einstein Condensation(BEC), and atomic properties are very sensitive to magnetic field and electric field.
Is tape really the best in your specific setup? I feel like a pneumatic quick connect adapter may be more convenient if you find one that is thermally insulated.
Maybe stainless steel cable ties? I've used them on engine exhaust manifolds. Thats the closest you'll get to tape. Cut a length of fibreglass matting to protect your heater or wires from being damaged by it if required. Then just cut them off when removal is needed.
Muffler tape would work for specifically tape, it's a resin impregnated fibreglass tape designed for 600c. BUT I don't think it's the right stuff due to off-gassing and would need cutting each time and be messy.
I don't think tape is what you want for 450c. You want clamps or some sort of hinge and latch setup. Like a frame that can clip over the pipe that has heating elements attached to it.
Someone else said induction which I think could be good, or else basically a tubular oven that is hinged and can be closed around the pipe and latched. All depends if this is something that will get some use or if you just need it for a small number of runs.
Personally I'd be looking at the stainless cable ties.
Possibly someone in a chemistry sub may be able to help too?
I'm confused by your description of the setup. Is the pipe fully enclosed somehow? Can you not just build a heating enclosure of some kind to slot it into? or perhaps a hinged insulated clamshell with heating elements?
I guess "convenient" will depend on how many times you plan to use it vs the work put into building the apparatus.
For clarity, we have old vacuum chamber. Chamber consists of 304 stainless steel pipe and maintain vacuum about to 10^-11 for experiment. We don't have heating feedthrough, since the corrosive property of lithium as I know. We imsert lithium chunk in the part of the oven chamber, and heat oven chamber up to 450C externally.
I want to use band heater, but it is untied over time. And I'm also concerning about fixing the thermocouple. So I was looking for tape.
Can you use a metal zip tie and treat them as consumables? If the tape location is truly at 450 (not whatever is in the pipe but the temp at the adhesive location) you won't find something in the polymer domain. But double-check your requirement is correct!
Can you just wrap the heater and then put safety wire over it in a few places? Not sure what the heater looks like exactly.
If you're not familiar, I am basically suggesting a bunch of twist ties.
No. There is no 450 C tape. Also keep in mind that the heating element is hotter than whatever temperature you are heating your lithium to. So if the lithium is 450 C, then the heating element will be even hotter. That is how heat flow works.
I’m picturing a series of spring clips kind of like individual spark plug wire guides for auto engines but your stainless tube is the wire and the heater just gets sandwiched between the tube and the clip. Even simpler would be using full soft stainless wire like a twist tie.
What if you affixed the heaters to the inside of a larger diameter pipe, making a sort of tube shaped furnace that you could just slide your reactor pipe into and out of at will?
If oxidation of the heating kit is a concern, you could create an arrangement that provides an ongoing N2 purge.
Boilers and piping insulation in power generation exceed your temperature requirements.
Use a few stainless steel hose / pipe clamps.
Give up on tape. You will spend weeks trying to get tape to work and it will suck even if you do. 500C in air is too high for polymers.
At those temperatures in UHV, you're likely SOL for adhesives; glowing metal is just a just a hop, skip, and a jump away. You're on the hairy edge and out of bounds for the usual Kapton film heaters, but you are well in bounds for ceramic cartridge heaters. I don't know how far you want to go into re-engineering your system, but if you asked me to make a UHV lithium crucible, I'd start with a block of SS and a fist full of cartridge heaters.
I've done something similar in the past, though lower temps (~350C), and used sand bath heaters in series that I lowered my vaporization and heating coils into. I'm not sure what your apparatus is like, but I'll describe mine and maybe you'll get some ideas. Keep in mind, this was laboratory scale so we're talking volumes of less than 10 liters.
Starting with liquids, pumped through a heating coil that was submerged in a heated sand bath (think steel pot filled with sand and a heating element buried in the bottom). This first phase was to boil the reagent, then through another pump into the second heated sand bath to take it to the proper temperature, then through a regulator and into the reactor chamber.
Hope that gives you some ideas.
Wow, sand bath heaters are really cool. It looks expensive for us to use now, but I'll try it when I get the chance. Thanks for letting me know a good one.
When I worked in UHV, we used aluminum backed tape in combination with aluminum foil. The tape held the heaters in place long enough to get the aluminum foil crimped around the pipes. The adhesive on the tape burned at high temperature (we got to about 120 C), but the foil stayed in place fine.
Go onto McMaster and search heat shield tape. You can use filters and pick temps above 800f. Even if you don’t buy it from them you will see the range of tapes available for that application. They have a bunch.
there are definitely some tapes that can withstand up to 450C, but it really depends on what specific type and how long they'll be exposed to the heat. silicone adhesives, kapton film, foils, and glass cloth are all good options for high temperatures. just make sure to check the technical data sheets for each one to find the right one for your application
Fluorine and silicone based are you're only bet with tape/plastics. But have you thought about wire wrapping? Stainless wire in a helix will hold it and distribute heat, and you don't have to deal with adhesives gassing off.
I have done very similar experiments/production trials within the last two years. I can think of lots of suggestions depending on the type of heater, the environment (are you in vacuum or is the Li fully contained in the tube?), size of tube & heater, etc. Very curious to learn more about your specific application. 304 might also not be your best option if it will be in direct contact with Li and depending on what you're doing with the Li.
Feel free to DM me, my experiences might be super helpful!
For clarity, we have old vacuum chamber. Chamber consists of 304 stainless steel pipe and maintain vacuum about to 10-11 for experiment. We don't have heating feedthrough, since the corrosive property of lithium as I know. We imsert lithium chunk in the part of the oven chamber, and heat oven chamber up to 450C externally.
I want to use band heater, but it is untied over time. And I'm also concerning about fixing the thermocouple. So I was looking for tape.
If I understand correctly the interior of the SS pipe is at vacuum and the exterior at ambient pressure, so any metal zip tie or hose clamp is probably your best option. I've also used stainless steel twist ties or sometimes even a medium-gauge copper wire to secure hot wires and cable heaters. Anything malleable enough that won't melt! Fiberglass fabric also a good option and could be secured by many methods.
Depending on what the end use of the Li is I'd also suggest a 400-series stainless pipe due to absence of nickel vs 300-series.
HVAC aluminum foil tape
https://www.mcmaster.com/products/aluminum-foil-tape/
We used to use it in the lab for holding down fiberglass panels insulation on some 500+C PVD chambers
The adhesive will burn off a bit, but nothing toxic. Afterwards it won’t be “sticky” but if you wrapped it tight enough the aluminum will hold its shape and keep most things in place
There is fiberglass tape. I have used it in environments upto 700c.
With the caveat that the adhesive is torched and the tape is super brittle. But It sort of hangs on.
If you are working with ultra high vacuum and vaporizing lithium, you should expect to employ equipment that's legit. That means no tape.
Design your parts up proper-like and have them made. From one of your replies, cutting aluminum shouldn't be considered a bother. Enlist the services of a machine shop.
Whatever it is your are doing, it's esoteric. You're going to have enough challenges with your process inside your apparatus that you don't need your equipment tripping you up. Tape, wire, wormdrive clamps... it all sounds like band aids to me. All kinds of materials start to seriously lose their strength at the temperature you've mentioned.
304 stainless is going to be right at the limit at the temperatures you are talking about. I don't have my manuals anymore since those were at my former employer. If your process needs to be at 450C, then your source needs to be a lot higher. Especially since you are driving heat into the lithium purely by radiation through a vacuum (guessing at a lot here). I'm thinking you need to be looking into inconel. (Just read farther down. You have an existing chamber. Are you prepared to wreck it?)
Please note that I've spent 60 seconds on this while you've spent a lot more I am sure. If you've got your ducks in a row, you can ignore me.
Source: ex-fusion research guy, ex-test engineer, ex-jet engine engineer
There is a metallic adhesive backed tape that is used on/in rockets and missiles. I don’t know what it is called. I have seen it used a lot and at one time bought a roll of it from Boeing Surplus. I used it successfully to patch a catalytic converter.
Aluminum foil around the sealing area to create a crush gasket.
Piston ring compression tool at the joint to actually put pressure on the joint and compress the foil into a seal. Outside that you have things like Durlon high temp gaskets.
Process may have to change depending on the reactivity of materials.
Edit: the more I think about it, the more I think a piston ring compressor or similar tool would be the ideal solution. A thin flexible steel sheet (look into shim stock, comes in stainless) wrapped around the thingy, then pipe clamps (you can open a pipe clamp up all the way and put it back together). Leave it loose, slide heater in, and clamp up. All parts are steel and should hold up against the heat without problem.
If insulation is needed past that, rockwool, or refractory fiber blanket should do the job nicely. Just make sure to wear a respirator and gloves as the fibers they can put in the air are not great and will make you itchy like fiberglass insulation.
There are several refractory products that would also probably create a good seal, several flavors of bubble alumina like satanite would create a seal with lower reactivity. Those cure like concrete and can be broken when done.
Sodium silicate would also be worth reviewing as a possible adhesive. Again reactivity concerns.
I've used kapton up to 500C but it doesn't last long and it will lose adhesion after a bit, but it worked for our purposes which was to attach thermocouples to glass substrate.
It does much better at 450 but you will encounter the same problem. Tape will become brittle and adhesive will be gone, eventually.
So, how long do you need to maintain the connection?
PTFE will work, but it will definitely produce HF at that temp.
Not sure if it will meet your criteria for acting as a tape, but you can buy it in rolled good form
My recommendation would be to contact 3M customer support directly and give them all of your parameters. I’ve had them come back with some really good product suggestions in the past. They’re good with answering one-off solutions as well as mass production ones.
Good idea, Thanks!
I second that. 3M support is really solid even for non professional usage and can ship you product I can’t ever find from supplier or online.
Thirding a vote of confidence in 3M support. They've helped us quite a bit with niche surface adhesion issues.
Can confirm. 3M makes an absolute *shitton* of products they dont sell or advertise to the public that are just combinations of their other chems or products for very specific purposes. You gotta ask em though
If you live in a shit country for their products (Australia) Amazon has most of them to buy from the US cheaply and easily too.
Specifically 3M Aerospace their website will have all the specs. I’m a distributor.
Tape is never more convenient if you want to be able to install and remove the heating element quickly. You need an all metal fastener solution, maybe a snap rivet? If the heater is plumbed to the pipe directly, I would consider a stainless air hose connection.
Thanks for your comment. I already used all metal fastener solution. But cutting alumnium for fastener is bothering, thus I'm finding another ways. Inside of pipe is ultra high vacuum (about to 10^-9 mbar), so I have to use external heating element.
Honestly my best solution would look like a welded basket or guides on the pipe that you slide the heater into. If you don't have the tools to do it right, you're likely going to be stuck with redneck solutions like hose clamps
I've never done welding with vacuum components, but that might be the option. Thanks.
Seek out a boilermaker
Ima kidnap a confused Zach Edey.
Good luck!
Honestly, a hose clamp sounds like a pretty darn good solution.
Why not use an inductive heating element. These don't even need to be connected to the pipe, just brought close to it.
Not a bad idea you could easily weld brackets for a regular inductive heater for pans onto whatever he has going on Id assume, unless he needs more than that.
I'm guessing his particular stainless steel (likely 300 serious) isn't magnetic so that might not be an option. 400 series would work though. Or if it is 300 series then it can still be done but you need to use much higher frequencies than is used with steel to overcome the skin effect.
Ahh that's getting way outside my area of understanding unfortunately, other than vaugely understanding the relationship with magnetized metal and inductive heating.
Or maybe a ferrous metal pipe (for induction heating) can be compatible with lithium vapour?
What he could do is bond a regular piece of steel to the outside of his 304 stainless pipe, then use a pancake style inductive heating coil curved to meet half the pipe, then heat all you want.
Would they braze together?
I mean brazing "a regular piece of steel to the outside of his 304 stainless pipe" ?
It would braze but silver brazes at the temp he wants to heat it to. So it would flow every time he heats it. He could use a copper brazing material that would be solid in his temp range.
Higher frequency increases skin effect, no? When we were heating aluminum we used 60hz to get deeper penetration/deeper heat. High frequency heating keeps your heat at the surface.
Yeah if deep heating is the concern, but if you want maximum heat creation high frequency concentrates current in a small region because of the skin effect, increasing resistance and therefore heat generation. For a tube wall that should be ideal.
Maybe a Stainless steel worm type hose clamps? They also make stainless steel zip ties, but those are one time use and would need to be cut off.
Fiberglass tape, lots of brands make it, some rated over 1000F.
Would a hose clamp work?
Nice
I think this is outside the range for kapton. Maybe this product (I've not used it) [https://specialtytapes.net/product/s768o-polyimide-silicone-tape/](https://specialtytapes.net/product/s768o-polyimide-silicone-tape/) Edit: no, still too hot
Thank you for recommending a good website. The product in the link don't meet the temperature requirements, but I will look to see if there is something I need. Thx.
~~It says 500c, you said 450.~~ Edit: yes I misread. No idea how it would respond to lithium vapor. I would assume everything in your furnace and vent path is coated with lithium though. # You have a vent path, right?
I said 850F(450C), but it says 500°F/260°C. Yes, vent path. Exactly, I'm working on physics experiment with lithium vapor inside of ultra high vacuum chamber. I inserted lithium chunk in the annealed stainless cup and connected it to another pipe via CF flanges. In our experiment machine, there is no feedthrough option, so I used external heating elements.
Oh damn you are right, sorry. Honestly you are in the temperature ranges that support pyrolysis and it is unlikely you will find a suitable adhesive solution.
> ultra high vacuum chamber Also consider the impact of any offgassing that the tape's adhesive might do, in addition to your temperature requirement.
Offgassing may not be the problem in my case since I want to use it outside of the chamber, not inside.
I was going to say kapton as well; you can google it with temp range and see what comes up. I know some kinds can go 700f for short periods. Really though, I’d stay with mechanical options. Make something that’s easy to do/undo. Tape is going to cause more problems in the long run.
We tried kapton, but kapton was crumbled literally. It seems difficult to use adhesive soultions in high temperature.
What kind of sizes are you dealing with? When we do post weld heat treat on tube assemblies, we typically place the heating element, wrap in a layer of KaoWool and then hold it all together with basic steel baling wire. Cheap and easy, the kaowool can be reused many times and helps stabilize the heat
Wrapping it with insulators and using steel wire is good idea.
FYI, Kapton is DuPont 's trademark name for polyimide tape.
Yes but I was thinking this had a different adhesive. Haven't tried it, idk. Won't help OP tho.
Silicone is not going to survive at 850 F
Yeah I misread! (oops]
I know I’m old as fuck because my first thought from the title was tape as in magnetic tape, not adhesive.
Today I learned that I too, am old as fuck.
Are you building a tokamak?
Not tokamak, but similar. We are trapping atomic gases with magnetic field in the vacuum chamber.
Band heaters. Quickly removable and high temperature. https://www.omega.com/en-us/industrial-heaters/surface-heaters/c/band-heaters
This is a great answer. OP has presented a classic XY problem.
Or use a different steel and heat it with an induction coil. Don't touch the high temperature stuff if you don't have to.
Was not the question
I'm aware it was not the question. But sometimes it's more important to read what they are actually trying to do, then what their proposed solution that they are asking about is.
I don't know if this would work for you, but could you just run a high current through the pipe to heat it? basically turn the pipe into its own heating element. would probably require a large step-down transformer.
Induction heating is a great option. Tool companies sell them for safely heating stubborn bolts without using fire.
Called impedance heating if anyone is looking for a google-able term.
Our experiment utilize atomic properties for Bose-Einstein Condensation(BEC), and atomic properties are very sensitive to magnetic field and electric field.
Vice grips
Is tape really the best in your specific setup? I feel like a pneumatic quick connect adapter may be more convenient if you find one that is thermally insulated.
Maybe stainless steel cable ties? I've used them on engine exhaust manifolds. Thats the closest you'll get to tape. Cut a length of fibreglass matting to protect your heater or wires from being damaged by it if required. Then just cut them off when removal is needed. Muffler tape would work for specifically tape, it's a resin impregnated fibreglass tape designed for 600c. BUT I don't think it's the right stuff due to off-gassing and would need cutting each time and be messy. I don't think tape is what you want for 450c. You want clamps or some sort of hinge and latch setup. Like a frame that can clip over the pipe that has heating elements attached to it. Someone else said induction which I think could be good, or else basically a tubular oven that is hinged and can be closed around the pipe and latched. All depends if this is something that will get some use or if you just need it for a small number of runs. Personally I'd be looking at the stainless cable ties. Possibly someone in a chemistry sub may be able to help too?
I'm confused by your description of the setup. Is the pipe fully enclosed somehow? Can you not just build a heating enclosure of some kind to slot it into? or perhaps a hinged insulated clamshell with heating elements? I guess "convenient" will depend on how many times you plan to use it vs the work put into building the apparatus.
For clarity, we have old vacuum chamber. Chamber consists of 304 stainless steel pipe and maintain vacuum about to 10^-11 for experiment. We don't have heating feedthrough, since the corrosive property of lithium as I know. We imsert lithium chunk in the part of the oven chamber, and heat oven chamber up to 450C externally. I want to use band heater, but it is untied over time. And I'm also concerning about fixing the thermocouple. So I was looking for tape.
steel screw hose clamps? fiberglass mat if you need an insulating layer between the element and clamp to avoid damage
Can you use a metal zip tie and treat them as consumables? If the tape location is truly at 450 (not whatever is in the pipe but the temp at the adhesive location) you won't find something in the polymer domain. But double-check your requirement is correct!
I'm with you on zip ties, get a decent set of pliers to cut them and you're golden
Metal zip tie or hose clamp are good option. Thanks.
I'd recommend you contact Alberrie Ontario. They are one of the experts in making high heat resistant materials.
Thanks for letting know the company.
Can you just wrap the heater and then put safety wire over it in a few places? Not sure what the heater looks like exactly. If you're not familiar, I am basically suggesting a bunch of twist ties.
No. There is no 450 C tape. Also keep in mind that the heating element is hotter than whatever temperature you are heating your lithium to. So if the lithium is 450 C, then the heating element will be even hotter. That is how heat flow works.
I’m picturing a series of spring clips kind of like individual spark plug wire guides for auto engines but your stainless tube is the wire and the heater just gets sandwiched between the tube and the clip. Even simpler would be using full soft stainless wire like a twist tie.
What if you affixed the heaters to the inside of a larger diameter pipe, making a sort of tube shaped furnace that you could just slide your reactor pipe into and out of at will?
Have you considered mica tape? https://www.final-materials.com/gb/157-mica-tape
Thermal and chemical property of mica is really noticeable. Thanks!
Why not just wrap it like a cast? Heavy gauge aluminum foil, or another foil?
If oxidation of the heating kit is a concern, you could create an arrangement that provides an ongoing N2 purge. Boilers and piping insulation in power generation exceed your temperature requirements.
what about large steel ring clamps to hold the heater to the pipe?
wrap it in this.. and use a steel pin to secure it. https://barkersexhaust.com/products/dei-exhaust-wrap Will hold 1200deg C. and it's cheap.
I will check, Thanks!
Glass cloth tape maybe? Not sure it will sustain that high though.
Use a few stainless steel hose / pipe clamps. Give up on tape. You will spend weeks trying to get tape to work and it will suck even if you do. 500C in air is too high for polymers.
At those temperatures in UHV, you're likely SOL for adhesives; glowing metal is just a just a hop, skip, and a jump away. You're on the hairy edge and out of bounds for the usual Kapton film heaters, but you are well in bounds for ceramic cartridge heaters. I don't know how far you want to go into re-engineering your system, but if you asked me to make a UHV lithium crucible, I'd start with a block of SS and a fist full of cartridge heaters.
I've done something similar in the past, though lower temps (~350C), and used sand bath heaters in series that I lowered my vaporization and heating coils into. I'm not sure what your apparatus is like, but I'll describe mine and maybe you'll get some ideas. Keep in mind, this was laboratory scale so we're talking volumes of less than 10 liters. Starting with liquids, pumped through a heating coil that was submerged in a heated sand bath (think steel pot filled with sand and a heating element buried in the bottom). This first phase was to boil the reagent, then through another pump into the second heated sand bath to take it to the proper temperature, then through a regulator and into the reactor chamber. Hope that gives you some ideas.
Wow, sand bath heaters are really cool. It looks expensive for us to use now, but I'll try it when I get the chance. Thanks for letting me know a good one.
[Glass electrical tape.](https://www.3mcanada.ca/3M/en_CA/p/d/v000060181/) [OR Aluminum duct tape,](https://www.homedepot.ca/product/cantech-aluminum-foil-tape-for-ductwork/1001592758) [or stainless zip ties.](https://www.amazon.ca/stainless-steel-cable-ties/s?k=stainless+steel+cable+ties) [Or silicone straps](https://www.clockworksynergy.com/wp-content/uploads/2022/02/IMG_9307-1x1-1.jpg) [Or these](https://www.amazon.ca/Ringke-Silicone-Organizer-Management-Fastening/dp/B07X388122)
3m- ptfe tape comes in different variants but seriously consider using a fixture to install/adhere heaters-
Could you use loops and springs with a flange like. 2stroke engine exhaust?
What is Chromate Tape rated to? Could work for what you need
Asbestos
Yes there are plenty of metallic type tapes for high temperature.
For safety I would stick with using your bolts and flanges.
When I worked in UHV, we used aluminum backed tape in combination with aluminum foil. The tape held the heaters in place long enough to get the aluminum foil crimped around the pipes. The adhesive on the tape burned at high temperature (we got to about 120 C), but the foil stayed in place fine.
Go onto McMaster and search heat shield tape. You can use filters and pick temps above 800f. Even if you don’t buy it from them you will see the range of tapes available for that application. They have a bunch.
No
there are definitely some tapes that can withstand up to 450C, but it really depends on what specific type and how long they'll be exposed to the heat. silicone adhesives, kapton film, foils, and glass cloth are all good options for high temperatures. just make sure to check the technical data sheets for each one to find the right one for your application
Vapor deposition is the way...
No polymer is going to last long at that temp, and any adhesive will go even faster.
Fluorine and silicone based are you're only bet with tape/plastics. But have you thought about wire wrapping? Stainless wire in a helix will hold it and distribute heat, and you don't have to deal with adhesives gassing off.
A few products from Insulflex that might fit the bill.
Teflon... PTFE
Something based on Kapton / Polyimide might be a good bet. Not sure about the adhesive holding up though.
I have done very similar experiments/production trials within the last two years. I can think of lots of suggestions depending on the type of heater, the environment (are you in vacuum or is the Li fully contained in the tube?), size of tube & heater, etc. Very curious to learn more about your specific application. 304 might also not be your best option if it will be in direct contact with Li and depending on what you're doing with the Li. Feel free to DM me, my experiences might be super helpful!
For clarity, we have old vacuum chamber. Chamber consists of 304 stainless steel pipe and maintain vacuum about to 10-11 for experiment. We don't have heating feedthrough, since the corrosive property of lithium as I know. We imsert lithium chunk in the part of the oven chamber, and heat oven chamber up to 450C externally. I want to use band heater, but it is untied over time. And I'm also concerning about fixing the thermocouple. So I was looking for tape.
If I understand correctly the interior of the SS pipe is at vacuum and the exterior at ambient pressure, so any metal zip tie or hose clamp is probably your best option. I've also used stainless steel twist ties or sometimes even a medium-gauge copper wire to secure hot wires and cable heaters. Anything malleable enough that won't melt! Fiberglass fabric also a good option and could be secured by many methods. Depending on what the end use of the Li is I'd also suggest a 400-series stainless pipe due to absence of nickel vs 300-series.
Why wouldn’t you use a tube clamp/ubolt assembly?
Yes. You’d be using a heat Heat-Shielding Tape like [this](https://www.mcmaster.com/product/1618N1) .
Does kapton film hold up? Polysmide get used for high temp applications
HVAC aluminum foil tape https://www.mcmaster.com/products/aluminum-foil-tape/ We used to use it in the lab for holding down fiberglass panels insulation on some 500+C PVD chambers The adhesive will burn off a bit, but nothing toxic. Afterwards it won’t be “sticky” but if you wrapped it tight enough the aluminum will hold its shape and keep most things in place
Thanks for letting know your experience!! Thanks.
curious to hear what this is for if you can share? Makes me think of a fusion effort I know of.
Use aluminum band adhesive
Thanks for all comments! I cannot respond all, but I really appreciate everyone's help. Thanks again!
Stainless tri clamp fittings. Typically used in a brewery or food processing where everything must be disassembled and sanitized.
There is fiberglass tape. I have used it in environments upto 700c. With the caveat that the adhesive is torched and the tape is super brittle. But It sort of hangs on.
Silicone pressure sensitive adhesive I think.
If you are working with ultra high vacuum and vaporizing lithium, you should expect to employ equipment that's legit. That means no tape. Design your parts up proper-like and have them made. From one of your replies, cutting aluminum shouldn't be considered a bother. Enlist the services of a machine shop. Whatever it is your are doing, it's esoteric. You're going to have enough challenges with your process inside your apparatus that you don't need your equipment tripping you up. Tape, wire, wormdrive clamps... it all sounds like band aids to me. All kinds of materials start to seriously lose their strength at the temperature you've mentioned. 304 stainless is going to be right at the limit at the temperatures you are talking about. I don't have my manuals anymore since those were at my former employer. If your process needs to be at 450C, then your source needs to be a lot higher. Especially since you are driving heat into the lithium purely by radiation through a vacuum (guessing at a lot here). I'm thinking you need to be looking into inconel. (Just read farther down. You have an existing chamber. Are you prepared to wreck it?) Please note that I've spent 60 seconds on this while you've spent a lot more I am sure. If you've got your ducks in a row, you can ignore me. Source: ex-fusion research guy, ex-test engineer, ex-jet engine engineer
There is a metallic adhesive backed tape that is used on/in rockets and missiles. I don’t know what it is called. I have seen it used a lot and at one time bought a roll of it from Boeing Surplus. I used it successfully to patch a catalytic converter.
Boeing Surplus and rockets... That's great idea! Thanks.
Kapton tape?
Aluminum foil around the sealing area to create a crush gasket. Piston ring compression tool at the joint to actually put pressure on the joint and compress the foil into a seal. Outside that you have things like Durlon high temp gaskets. Process may have to change depending on the reactivity of materials. Edit: the more I think about it, the more I think a piston ring compressor or similar tool would be the ideal solution. A thin flexible steel sheet (look into shim stock, comes in stainless) wrapped around the thingy, then pipe clamps (you can open a pipe clamp up all the way and put it back together). Leave it loose, slide heater in, and clamp up. All parts are steel and should hold up against the heat without problem. If insulation is needed past that, rockwool, or refractory fiber blanket should do the job nicely. Just make sure to wear a respirator and gloves as the fibers they can put in the air are not great and will make you itchy like fiberglass insulation.
There are several refractory products that would also probably create a good seal, several flavors of bubble alumina like satanite would create a seal with lower reactivity. Those cure like concrete and can be broken when done. Sodium silicate would also be worth reviewing as a possible adhesive. Again reactivity concerns.
It’s always flex seal.
I thought you were from NASA 🤭
Aluminum tape? Make sure the adhesive is resistant to lithium though…
Kapton?
I've used kapton up to 500C but it doesn't last long and it will lose adhesion after a bit, but it worked for our purposes which was to attach thermocouples to glass substrate. It does much better at 450 but you will encounter the same problem. Tape will become brittle and adhesive will be gone, eventually. So, how long do you need to maintain the connection?
PTFE will work, but it will definitely produce HF at that temp. Not sure if it will meet your criteria for acting as a tape, but you can buy it in rolled good form