F30 elbow

I've just replaced the elbow but there seems to be a lot of air and noise coming from it, so I think it may be faulty. Previous one was quiet.
Question is when I do the mask test it says its fine and doesn't make a noise, but the minute the pressure drops to 4 its very very loud.

Is this normal? Hospital not open till Monday so any help would be appreciated

Hettering80 wrote: ↑

Sat Nov 04, 2023 8:16 am

Is this normal?

No.

This is hard to diagnosis without seeing the mask.

What are your pressure settings?

When does the pressure run at 4.0 cm?

Most people cannot tolerate a pressure that low. You might raise the pressure until you can have your supplier look at the elbow.

Hettering80 wrote: ↑

Sat Nov 04, 2023 8:16 am

I've just replaced the elbow but there seems to be a lot of air and noise coming from it, so I think it may be faulty. Previous one was quiet.

Can we assume that you replaced the F30 QuietAir elbow because it was broken or because it didn't latch securely?
The Quietair elbow should be quiet at all pressures when properly seated in the frame.

The intentional leak (vent in the elbow) is 19 l/m @ 3cmH20, barely observable.

dataq1 wrote: ↑

Sat Nov 04, 2023 11:06 am

The intentional leak (vent in the elbow) is 19 l/m @ 3cmH20

No, that's the total passive vent rate including the vent in the mask itself.

ChicagoGranny wrote: ↑

Sat Nov 04, 2023 4:52 pm

dataq1 wrote: ↑

Sat Nov 04, 2023 11:06 am

The intentional leak (vent in the elbow) is 19 l/m @ 3cmH20

No, that's the total passive vent rate including the vent in the mask itself.

Everything is vented in the elbow, the air passing thru the slots in the cushion support go into the elbow. As far as I see there are no other "vents" except in the elbow.

But the real point is: Why would the "elbow noise" be "very very loud" at 4 cm pressure but with higher pressures much quieter?

The elbow has a clip on each side that attach to the mask. Are both sides clipped in properly? If you have just one clip seated and the other one is loose, you will get a lot of noise.

I'm not familiar with this mask but I assume that, like other full face masks, it has a non return valve so you can breathe if the machine shuts down.....it's possible that this is leaking at the lower pressure?

Garethep wrote: ↑

Sun Nov 05, 2023 3:46 am

I'm not familiar with this mask but I assume that, like other full face masks, it has a non return valve so you can breathe if the machine shuts down.....it's possible that this is leaking at the lower pressure?

Correct.

The F30 Elbow has two flaps on the sides, they drop open when there's no pressure, and pressurize air flaps them shut.

On the very rare occasions the flap don't shut, I find that blowing out firmly shuts them.

So there are two possible explanations:
The elbow itself isn't fixed correctly to the mask -
The anti-asphyxia valve remain open when the pressure is too low.

Garethep wrote: ↑

Sun Nov 05, 2023 3:46 am

I'm not familiar with this mask but I assume that, like other full face masks, it has a non return valve so you can breathe if the machine shuts down.....it's possible that this is leaking at the lower pressure?

The valve that you reference is the anti-asphyxiation valve. It relies on flow, not pressure, to close off the external ports. But what you said otherwise, that a mal-function of either of these two flaps that causes the causes the external ports to not seal would result in blower flow to leak out these ports.
Regardless, the elbow is either not seated and secured properly or the elbow is defective.

Did you replace the elbow with one of the older type of elbows? These elbows vented directly without the baffle over the vent holes. They were sometimes a little noisy if something was in front of the vent holes.

Hettering80 wrote: ↑

Sat Nov 04, 2023 8:16 am

I've just replaced the elbow but there seems to be a lot of air and noise coming from it, so I think it may be faulty. Previous one was quiet.
Question is when I do the mask test it says its fine and doesn't make a noise, but the minute the pressure drops to 4 its very very loud.

Is this normal? Hospital not open till Monday so any help would be appreciated

Hi,

Did you ever fix this issue? I’m having the exact same problem with a new F20 mask.