An improved pressure relief valve, comprising:
- a main body with a tubular shape and comprising an air inlet and an air outlet provided on two ends thereof, a channel with a smaller diameter provided between said air inlet and said air outlet;
- said channel comprising a through-hole penetrating through said main body;
- and said through-hole comprising a pressure relief perforation penetrating through a wall of said main body;
- a pressure adjustor comprising a sleeve;
- said sleeve comprising a guiding hole and a leakage-directing hole penetrating therethrough and an air conduit fluidly connected to said guiding hole;
- said sleeve further comprising a securement base provided therein;
- an anti-leakage rubber mounted at a bottom of said securement base;
- a top-engagement base provided on a top of said securement base;
- a spring provided between said top-engagement base and said securement base;
- said top-engagement base comprising a label disk mounted thereon and further secured onto an adjustment base;
- said adjustment base secured onto said sleeve;
- and said sleeve secured onto said through-hole of said main body;
- an anti-reverse member, comprising a shaft mounted onto and penetrating through an elongated slat;
- said elongated slat mounted onto said air outlet of said main body;
- another end of said shaft comprising a conical body having an O-shaped ring provided thereon;
- a spring provided between said conical body and said elongated slat in order to position said shaft and to allow said anti-reverse member to be moveable;
- whereby, during an operation of said pressure relief valve, said air inlet of said main body is connected to an air pump and said air outlet is connected to a filling-article of a tire;
- a pressure value of said filling-article is preset with said pressure adjustor;
- and under a normal condition, said
- anti-leakage rubber of said pressure adjustor blocks said air conduit of said main body in order to force air from said air pump to push said anti-reverse member toward said air outlet and to form an adequate gap allowing air to pass therethrough and to fill up said filling-article;
- and whereby when said filling-article reaches said preset pressure value, air pumped from said air inlet forces said securement base of said pressure adjustor and said anti-leakage rubber to move upward for an upward engagement such that said anti-leakage rubber disengages from said air conduit to allow air to be released from said pressure relief perforation of said main body;
- and
- whereby said conical body of said anti-reverse member engages a slanted section of said channel of said main body to form an anti-reverse engagement in order to stably maintain said filling-article at an air-filling state within said preset pressure value.