This is a note on the Douma gas cylinder valves which are obviously important to the Douma investigation.
Eliot Higgins, who has put together the helicopter-dropped chlorine bomb narrative, thinks the casings on the gas cylinders are there to support fins to ensure the cylinder lands on the gas valve (he calls it a “pressure valve”) on the front of the cylinder:
However, questions on how this set-up is supposed to function as a “chlorine bomb” have gone unanswered by Higgins.
Chlorine cylinder valves
To understand how a chlorine cylinder valve works here are some images:
The valve stem is turned to open or close the valve:

Opening the valve stem releases chlorine (gas or liquid) through the valve outlet.
This shows how the valve outlet cap is taken off using a wrench:

The nut surrounding the valve stem, known as the packing nut, keeps the mechanism tight:

Bed cylinder
What we see on the bed in the Douma imagery is a normal intact valve with the valve outlet cap in place.
Cylinder valve pictured on morning of the 8th (on the left) and after the Russians arrived (on the right).
Unsurprisingly, there has been no answer to the question of how this “chlorine bomb” is supposed to work.
There are no images of any victims in this house and the chickens inhabiting one of the rooms are still alive.
One explanation for this is that the cylinder was not dropped from a helicopter, has not been modified as a chlorine bomb in any way and is just a staged artefact.
It is of course still possible chlorine from this cylinder entered the house. If so it would most likely be as a result of the valve being deliberately opened or, possibly, the cylinder having been heated to blow the fusible plug (which is not visible on any of the imagery so far published.)
Balcony cylinder
There has also been no imagery published to show the state of the cylinder valve inlet threads in the balcony scene.
Higgins has failed to answer if the unpublished photo he received of the balcony scene includes an image of the front of that cylinder.
All we have, so far, are images showing the thread for the protective cap which goes over the valve, showing that that is intact. The valve itself is, at least largely, missing:

It does not look like this cylinder has any signs that the valve was smashed into the body of the cylinder – as one might expect if it was dropped onto concrete from a helicopter.
Smashing a valve off a cylinder requires considerable force applied laterally and will leave the inlet threads considerably damaged or (possibly) snap the valve off at the point where the valve inlet threads enter into the body of the cylinder.
It seems remarkable that no imagery of the valve from this location has been produced.
It will be very interesting to see if
- The threads are undamaged and the valve has simply been unscrewed
- Remnants of the valve bottom remain inside the cylinder thread
- The cylinder thread is twisted and torn as if it has been yanked out by force
In any case, without an explanation of how these supposed chlorine bombs were supposed to work, without any mechanism visible to explain how chlorine was released and with key evidence apparently withheld it seems the helicopter-borne narrative is “hanging by a thread.”