fengda airbrush question?

[Andy T]

The one with the metal O ring is generally a safety valve and should be left well alone. Some do release the pressure from there but you shouldn't really.

Better to use the drain tap / screw underneath as Jim says

 

[Modler bob]

The one with the metal O ring is generally a safety valve and should be left well alone. Some do release the pressure from there but you shouldn't really.

Better to use the drain tap / screw underneath as Jim says

Cheers andy.
At what pressure does it open then?

 

[Tim Marlow]

Cheers andy.
At what pressure does it open then?

Hi Bob. It will be set above maximum compressor working pressure, but well below tank safety test pressure. It will be there to protect the tank against malfunction of the compressor limit switch (leading to the tank being overpressurised) and should be factory set, so leave well alone. If it is continually disturbed the valve seat can become damaged leading to weeping and an inefficient seal. As Andy says, drain air from the tank using it drain tap. It’s what it’s there for

 

[Andy T]

Cheers andy.
At what pressure does it open then?

Technical answer - bloomin' lots

If it ever blows, don't hang around to find out as it means something is seriously wrong!

 

[Tim Marlow]

Technical answer - bloomin' lots

If it ever blows, don't hang around to find out as it means something is seriously wrong!

Usually about 25 % of maximum tank pressure Andy….and that itself is usually a very conservative value
Don’t panic, just pull the power and you’ll be fine……the overpressure relief valve (ORV, safety valve) is supposed to be sized to bleed enough air out to prevent overpressurisation from attached kit like compressors. The higher the overpressurisation the wider it opens and the more air it lets out.

 

[Modler bob]

Usually about 25 % of maximum tank pressure Andy….and that itself is usually a very conservative value
Don’t panic, just pull the power and you’ll be fine……the overpressure relief valve (ORV, safety valve) is supposed to be sized to bleed enough air out to prevent overpressurisation from attached kit like compressors. The higher the overpressurisation the wider it opens and the more air it lets out.

I hope I haven't disturbed the pressure by trying to pull it out then Tim, I did manage to just move it a tad, but not much though

 

[KarlW]

My pressure switch failed and my tank ran overnight once, I'm guessing it blew off at some point, or that there's enough leaks to keep it safe........either way nothing burst.

 

[Tim Marlow]

I hope I haven't disturbed the pressure by trying to pull it out then Tim, I did manage to just move it a tad, but not much though

No worries mate. If you wound it down a tad it will just go slightly early…..if you wound it up it will go a little later, but not enough to worry about. You’d have to seriously wind it up (several turns I should think) to materially change the values.

 

[Modler bob]

Thanks again for all the advice guys

 

[stillp]

I hope I haven't disturbed the pressure by trying to pull it out then Tim, I did manage to just move it a tad, but not much though

Just pulling it out won't do any damage. Some people recommend doing that occasionally to make sure the safety valve isn't stuck.
Pete

 

[Modler bob]

Crickey, this kit must be flying off the shelf.
It's gone up in price already, not by much though.

 

[Waspie]

Good thread, answered many questions from me!!
(Already collecting suitable cardboard boxes).