Does the first stage or second stage have some type of filter in it?

[William Ryan]

Hello all, just curious to know if the first stage or second stage has some type of filter in it to prevent breathing in anything dangerous from a tank like a hypothetical small shard of metal or plastic? If there is a filter does this get replaced once a year during the annual regulator maintenance? Thanks for the help!

 

[rsingler]

Yes. The first stage has a "sintered metal filter" right at the tank connection, that should take care of any pieces like those you suggested. You can see it in some regs if you look at the yoke attachment. It's often held in place by a star retainer.

 

[2airishuman]

Most first stages have a sintered brass inlet screen that mainly serves to prevent foreign objects from entering the regulator while it is detached from a cylinder. Typically they are in fact replaced when the reg is serviced. Second stages typically do not have a filter or screen of any kind.

Generally, there should be no particulate matter in the air source. While Grade E breathing air specifications do not include a particular matter limit, most compressor systems filter out particles through a submicron filter element.

There have been a couple of accidents over the years where particulate matter clogged the tank valve due to corrosion or contamination in the cylinder. These accidents are rare.

 

[William Ryan]

Yes. The first stage has a "sintered metal filter" right at the tank connection, that should take care of any pieces like those you suggested. You can see it in some regs if you look at the yoke attachment. It's often held in place by a star retainer.
View attachment 669101

thank you for the help! I will take a look to see if I can spot mine later. Safe diving!

 

[William Ryan]

Most first stages have a sintered brass inlet screen that mainly serves to prevent foreign objects from entering the regulator while it is detached from a cylinder. Typically they are in fact replaced when the reg is serviced. Second stages typically do not have a filter or screen of any kind.

Generally, there should be no particulate matter in the air source. While Grade E breathing air specifications do not include a particular matter limit, most compressor systems filter out particles through a submicron filter element.

There have been a couple of accidents over the years where particulate matter clogged the tank valve due to corrosion or contamination in the cylinder. These accidents are rare.

Thanks for the help! and yes I would hope that my air is free of any physical or invisible contamination! I just got a new cylinder and thought to myself what if by any chance there was a missed piece of metal or something I could breath in, that's what got me thinking about a filter. Safe diving!

 

[SlugLife]

All of my first-stages so far have a small metallic filter. None of my second stages have one.

If you're diving with a sketchy-tank, you could still have other issues, such as breathing in bad air or contaminants like oil. Some metal flaking off could also clog up the air-passage or air-filter as well. If you purchased a used cylinder, the standard VIP inspection should catch a lot of those kinds of issues & using a (non-sketchy) dive-shop for fills.

 

[jakehbk]

The 1st stage filter protects against crud and particles. Most are visible by looking thru the inlet. Theres also a dip tube on the bottom of your tank valve to help prevent crud from the tank from going thru the valve. You used to be able to buy aftermarket filters to go in line with the 2nd stage. If you are that concerned you could find one of those.

 

[William Ryan]

The 1st stage filter protects against crud and particles. Most are visible by looking thru the inlet. Theres also a dip tube on the bottom of your tank valve to help prevent crud from the tank from going thru the valve. You used to be able to buy aftermarket filters to go in line with the 2nd stage. If you are that concerned you could find one of those.

nice, thanks for the help!

 

[William Ryan]

All of my first-stages so far have a small metallic filter. None of my second stages have one.

If you're diving with a sketchy-tank, you could still have other issues, such as breathing in bad air or contaminants like oil. Some metal flaking off could also clog up the air-passage or air-filter as well. If you purchased a used cylinder, the standard VIP inspection should catch a lot of those kinds of issues & using a (non-sketchy) dive-shop for fills.

thanks for the help!

 

[emoreira]

invisible contamination

First stage inlet filter will not protect you from invisible contamination like Carbon Monoxide or Oil vapors.
Where you take your tank for a fill is a paramount aspect. Breathing air quality is the most important aspect you need to consider when taking your tank for a fill.
The installation of the fill station can indicate the expected quality of the air. A fill station that has no concern to show you the periodic air quality assessments is a good place to get fills.