Explosion Venting

The trigger mechanism can be the same value, regardless of the door size, and so can the area of the trigger initiator because it is the "initiator" and not the actuator.

It doesn't open the door it just lets the mechanism work after the door is open to keep it open. The actuator can be sized according to door weight since the doors will be opened by the blast.

I remember a demonstration in 5'th grade involving an empty paint can, votive candle, rubber tube and small amount of flour. Bounced the lid off the cieling. Very impressive and memorable but try doing that today. The kids will be getting their master's by the time you get the permits.

I am trying to understand your question fully... The only question you ask is "...what force gauge would messure that amount?" I am not certain this is the real question. Would you consider a few questions from me:

"We have to test an explosion vent that has a release pressure of 25lbs/sqft." Are you an independent certification lab? That is to say, why do you have to do this test?

When you perform this test, what fuel source or combination are you going to use for the deflagration? What... no explosion? I was sort of looking forward to watching that.

Do you have a copy of NFPA 68? Have you read it?

Thank you for all the input as it was quite helpful. I am sorry if my question wasn't clear as I am just a laymen, as you might have figured, but the actual question is how do I test this unit if it is claiming to open at 25lbs/sqft. Do I just hook on a force gauge, give it a tug and the door should open with a force of about 25 lbs? We do not have access to an air cannon and there are too many units, 60 in total, that are about 60 feet off the ground on a storage facility to hook up anything from below. We have to maintain the building and we want to make sure that they open as required, for safety and insurance reasons. We could presssurize the building but that seems a little excessive if all we need is a force guage.

These expolsion relief vents...

Are the devices a manufactured item? With a manufacturers nameplate, compliance data, date of manufacture, etc. If yes, what does the manufacturer have to say? If no, do you have the original fabrication data and design spec?

I know this is not really your question, but it will be useful to know if the original design was within your required performance today.

Do I just hook on a force gauge, give it a tug and the door should open with a force of about 25 lbs? No, the force unit is lbs/sqft. So, calculate the area of explosion door in sqft and multiply with 25 lbs to get required force to just hook on a force gauge to test. For example if area is 10 sqft, you have to hook 250 lbs. With this calculated load if door is not opening, then its weight is to be reduced. If opens with less load, weight is to be added.

You could test them with controlled releases from an air cannon (similar to those seen on Mythbusters) sealed to their housing and with pressure monitors installed.

This would give you control, adjustment, measurability and a realistic scenario.

With all my dealings with explosion doors we called the manufacturers in to test them. Simply to get the insurance cover.

After seven explosions in one night, I'm just glad they worked!