My locked fire cape just broke, why

Hello, I locked my fire cape with perdu (I payed the 500K with the perdu parchement), and after only like 3 deaths in pvp in varrock the fire cape broke. After fixing it with perdu, its a simple fire cape again. Any idea of why ? The idea of locking the fire cape is to prevent it do break after you die...
Thanks for your help !

 

Exactly. Thats the whole point of it. And it worked for a few times, and then it just broke as if i never used the scroll...

 

It sounds like you're only using this parchment to pk on a PVP world at g.e. In this case, you're misunderstanding the purpose of parchments. It isn't to avoid paying the small fee to fix a broken item, it's to protect the item if you venture above 20 wilderness.

 

This depends if the parchmented item is protected or not. If you're a pure in minimal risk with infernal cape (i), and the cape is your +1, you won't need to fix it everytime you die and thus won't to reparchment it. But if you used infernal cape (i) with ags, whoever kills you would get the 500k GP and you'd have to reparchment the cape.