malkaffeemalte
Aerospace
- Sep 30, 2020
- 1
Hello fellow engineers,
I'm new to this platform so please forgive me any dumb question.
To my job as a propulsion engineer I'm equally new, which is why I find myself faced with plenty of new tasks every day which I only heard of remotely during my uni life.
In particular, this thread is about the general understanding of seals and how they behave.
Example: Within a part that has to be transported, there is a valve with a certain (given) leakage rate, some pipes downstream of the valve and an opening at the end which has to be closed (and properly sealed).
The question is: Which seal would have to be used to properly seal off this opening? To my understanding, this depends on the pressure that the seal will have to withstand (right?). Does the leakage rate of the seal depend on the pressure, too? If I'd imagine this, it would be tight to a certain pressure and at that point, the medium (that leaked through the valve and now pressurises the volume between the valve and the closing cap) would start "whistling" through the seal of said cap. So then there would be an equilibrium pressure inside this volume, which should be a function of the valve leakage and the (pressure dependant) leakage of the sealed cap, right?
Could anyone explain to me, how to find an appropriate seal and how to calculate the corresponding leakage rate and equilibrium pressure inside the volume?
If I remember correctly, it also has to do something with the "preloading" force of the screws... For this, there's also a fixed (maximum) value (given by the manufacturer of the mounting cap).
Sorry for potentially wasting your time with suchlike "basic" questions but it would save my week if you could shed some light on this for me...
Thanks a lot for your help and
best regards from Germany,
malkaffeemalte
I'm new to this platform so please forgive me any dumb question.
To my job as a propulsion engineer I'm equally new, which is why I find myself faced with plenty of new tasks every day which I only heard of remotely during my uni life.
In particular, this thread is about the general understanding of seals and how they behave.
Example: Within a part that has to be transported, there is a valve with a certain (given) leakage rate, some pipes downstream of the valve and an opening at the end which has to be closed (and properly sealed).
The question is: Which seal would have to be used to properly seal off this opening? To my understanding, this depends on the pressure that the seal will have to withstand (right?). Does the leakage rate of the seal depend on the pressure, too? If I'd imagine this, it would be tight to a certain pressure and at that point, the medium (that leaked through the valve and now pressurises the volume between the valve and the closing cap) would start "whistling" through the seal of said cap. So then there would be an equilibrium pressure inside this volume, which should be a function of the valve leakage and the (pressure dependant) leakage of the sealed cap, right?
Could anyone explain to me, how to find an appropriate seal and how to calculate the corresponding leakage rate and equilibrium pressure inside the volume?
If I remember correctly, it also has to do something with the "preloading" force of the screws... For this, there's also a fixed (maximum) value (given by the manufacturer of the mounting cap).
Sorry for potentially wasting your time with suchlike "basic" questions but it would save my week if you could shed some light on this for me...
Thanks a lot for your help and
best regards from Germany,
malkaffeemalte
