Introduction: PPE Respirator: RubenValve Paint Sprayer Mask
Consider this as a set of thoughts on a possible PPE respirator made from a modified paint sprayers mask.
It is not a recommendation for use.
This is one for Anaesthetists / Anesthesiologists / Hospital staff really as it does contain a rather rare item called a Ruben Valve.
Other valves would probably work but this arrangement was discovered by accident and it is very neat and compact. I use this site often, so will document it here.
The Ruben valve has 3 ports:
When you inhale through the red port, gas will enter through the blue port.
When you exhale through the red port, the valve will change state and exhaled gas will exit through the yellow port.
If you put a viral filter on the inlet port, i.e. the blue port, then you may have a functional respirator.
Furthermore I have experimented with a hose on the inlet port, with the viral filter attached to its end. If you pass it back over one shoulder so it hangs down inside your blues top behind your back, then your blues might arguably function as an initial layer of protection for the filter.
Paint sprayer's mask
Ruben Valve - mine was from Intersurgical Ltd.
Hose 22mm i.d. (Optional)
A means of occluding the front port. I used a 3D printed disc.
Step 1: The Paint Sprayers Mask We Start With
Here is the mask I started with.
The inlet valves are part of the side filters unfortunately which makes it harder to adapt the mask to medical viral filters.
Step 2: Remove the Filters
Remove the filters. This will leave a circular hole on each side of the mask.
Step 3: Trim Away Excess Rubber
The mask is made of soft rubber.
With small sharp pointed scissors trim away all the excess rubber that used to hold the outer rim of the filters in place.
The cut away rubber is shown each side.
Step 4: Trim Away Front Valve
For this design the front exhale valve of the mask is not used.
Remove it, remove the flexible disc and trim away the splines as shown.
Step 5: File It Round
File this area so it forms a circular hole.
Step 6: Ruben Valve
As on the first page, if you breathe through red port, gas enters through blue port and exits through yellow port.
This version can be dismantled for cleaning also - with care.
Step 7: Insert the Ruben Valve Into Mask
This is the part I discovered while playing around trying to make this a neat design. Much neater than just fitting the Ruben valve red port into the front hole we have just made so it hangs out of front of the mask.
Insert Ruben valve as shown INSIDE the mask so the blue port emerges through one side hole and the yellow exhale port emerges though the opposite side hole.
The rubber will grip the Ruben valve on each side, purely by coincidence. You may want to make sure there is no leak at all here on each side by adding glue.
Step 8: Unscrew Red Port Inside the Mask
Unscrew the red anodised alloy port (unless you want it sticking into your mouth). This will not remove any key parts of the internal changeover valve mechanism.
Step 9: Turn Internal Port to Face Downwards
Turn the Ruben valve so the internal port faces downwards.
You don't want any moisture etc to collect inside valve internals, you want it to fall out downwards.
Step 10: Create an Occluder for the Centre Front Hole You Have Made.
I 3D printed the white part.
It fits into the hole and is glued in place with a hot glue gun to fully occlude the hole. This could be done in other ways.
Step 11: .stl File for the Round Occluder
If you want to print this part, here is the .stl file for it.
Step 12: Attach a Medical Viral Filter
Attach a medical viral filter
Step 13: All Done
Alternatively see next step for extension hose option.
Step 14: Optionally, Add a Short Hose
Optionally, add a short medical 22mm i.d. hose and put the filter on the end of it.
Step 15: Put Hose Over One Shoulder
Put hose over your shoulder and drop it down behind your back, under your shirt.
Your shirt may then provide an initial layer of protection pre-filter. It improves your view downwards too slightly if you choose the angle connector carefully as the filter is now not right by your face.
Step 16: Relatively Neat and Compact
You may look like a nuclear scientist but this arrangement is very neat and compact compared to some I have seen.