At every major intersection, and at the entrance to each room, the Battlestar Galactica has very large pressure doors. These doors each have a handle and a large wheel on each side. During regular operation crewmembers open the door with the handle and close it firmly, but do not spin the wheel. Occasionally, we see crew using the wheel as a leverage point to close the door.
Sealing it off
We never directly see a crewmember spin the wheel on the door after it closes. While Chief Tyrol is acting as head of damage control, he orders all bulkheads in a section of the ship sealed off. This order is beyond the typical door closing that we witness day-to-day.
This implies that the door has three modes: Open, Closed, and Sealed.
Crewmembers could use the door most of their day in an open or closed mode, where an easy pull of the handle unlatches the door and allows them to enter or leave quickly. In an emergency, a closed door could be sealed by spinning the valve wheel on one side of the door.
As with other parts of the Galactica, the doors are completely manual, and cannot be activated remotely. (Because Cylon hacking made them go network-less.) Someone has to run up to the door in an emergency and seal it off.
One worry is that, because there is a valve wheel on both sides, an untrained crewmember might panic and try to unseal the door by turning it in the wrong direction. This would endanger the entire crew.
The other worry is that the valve spins along a single axis (we see no evidence either way during the show), requiring the crew to know which side of the door they were on to seal it against a vacuum. “Righty Tighty, Lefty Loosey” would fail in this instance, and might cause hesitation or accidental unsealing in an actual emergency.
Ideally, the doors would have wheels that spun identically on either side, so that a clockwise spin always sealed the door, and a counter-clockwise spin always unsealed it.
Current water-tight doors have two sides, the ‘important’ side and the ‘unimportant’ side. The important side faces towards the ‘center’ of the vessel, or the core of the larger block of the ship, and can be sealed off quickly from that side with a wheel and heavy ‘dogs’.
Weathertight doors have a handle-latch on both sides that is connected (much like a doorknob), and can seal/unseal the door from either side.
If there is a technical limitation to that mechanism (unlikely, but possible), then a large and obvious graphic on the door (a clockwise or counterclockwise arrow) could serve to remind the crew which direction of turn sealed the door. In this case, sealing the door is the primary action to call out because it is the action done under a panic situation, and the action most easily forgotten in the heat of the moment.
Otherwise, the doors could be a danger to the crew: the crew on the ‘safe’ side could seal the door against depressurization, but crew on the ‘unsafe’ side might try to unseal it to save themselves in a panic.
Air pressure might keep the door properly closed in this instance, but it is still a risk.
We see during the damage control incident that the doors are quickly closed and sealed by the crew, even in an emergency, making the rest of the ship airtight. This either shows that the doors are effective at their job, or the crew is very well trained for such a situation.
Like the rest of the Galactica, the technology relies on people to work. A couple hints or minor tweaks to that technology could make the crew’s lives much easier without putting them at danger from the Cylons or the empty void of space.