Nerf Mods: A Beginner's Guide

Step 13 Pump Guns - Over-Pressure Release Valve Plug

All pump guns have Over-Pressure Release Valves. As mentioned in Step 6, this valve leaks air when the pressure in the gun is too high. So, for instance, if you pump a gun up to 35 PSI, further pumping will not result in any more pressure going into the gun. This is because the air you are trying to pump into the pressure chamber is just leaking out of the pump tube. This valve can be plugged to achieve higher pressures in the pressure chamber. This higher pressure results in a much higher range in Nerf guns. However, if they perform this mod, you must be careful. Pumping your gun way beyond pumping limit can result in your pressure chamber rupturing. Then, your Nerf gun will not function and will be nearly impossible to repair.

The actual modification is extremely simple. First, find the hole in the head of gun's pump. This hole is where the valve is situated. Using a hot glue gun, place a bead of glue over the hole, and once it dries, you're done! Just remember, be careful with plugged OP valves, you do not want to break your gun.

Comments

[flashanimator]

I tried to find the over pressure valve on the Nerf Airtech 2000 but could not find it. It appears that after you pump it the overpressure valve is a small two small plastic circles screwed together. I unscrewed these before and thats where the air must be held. If I were to hot glue the screws in place and seal all the places where air can leak out of it would that allow it to hold in more air?

[geek27]

It should probably look like a hole in the plunger head--here's a fairly simple write up with a picture of that hole.  You can always find other AT2K mods at the NerfHaven mods directory too!

[flashanimator]

ok thank you, I thought it was that 6 screws totals two plastic circle thing, couldn't find it before guess i needed to unscrew the black handle. Thank you for the help.

[nathe0]

One solution could be to wrap a layer of duct tape (or similar) around the existing pressure chamber. This would at least provide some additional support. 

[geek27]

The user "mettaurlover" mentioned something similar earlier.  Although it will add some support, I wouldn't exactly suggest relying in that.  With duct tape, you can't exactly wrap tape around every part of the chamber.  Any uncovered parts would still be prone to rupturing if you over-pump.  So, if you use duct tape, be careful!

[nathe0]

I admit, it would be tricky. Even another 5-10psi (or just added safety at regular pressure) would be good though.

My flat-mate (a pilot) recommends the patch tape they use on aircraft, its a tougher, stickier version of duct tape than you get at the hardware store.
Often called "100 mile an hour tape" as its used to make temporary repairs to the outside of aircraft. 

[Michel7788]

couldnt you reinforce the pressure chamber or replace it with something metal? i doubt anyone would have the muscle power to rupture a metal one, and i'd think the glue (or the entire valve?) will rupture first by then

[geek27]

Well, the thing is, it would be difficult to make one out of metal. In the example of replacing the actual pressure chamber, it would be pretty hard to do. The hard part would be making a trigger pin that seals correctly. You would have to drill holes in the pressure chamber the correct size for the pin to slide through, then you would have to use O-rings and glue them down with a certain degree of precision. In the end, it would probably leak. As for simple reinforcement, you could probably cover most of the chamber with metal, but as for the small portion of the chamber that is uncovered, that would probably rupture if you pushed your gun to its limits.