A safety valve for interrupting the flow of fuel through a fuel line includes a housing member and a safety valve insert, wherein the housing member houses a portion of the safety valve insert and the valve insert includes a connection end for connecting to a grounding surface to draw electrical current through the safety valve insert, a fusible link, which is broken by electrical current, and a plunger, which is released when the fusible link is broken and interrupts the flow of fuel through a fuel line.
1. A safety valve for interrupting the flow of fuel through a fuel line, the safety valve comprising:
a housing member having a fluid passage therethrough, the housing member comprising:
an inlet orifice and an outlet orifice in fluid communication, the inlet orifice dimensioned for receiving a first fuel line and operable for permitting the flow of fuel into the housing member, the outlet orifice dimensioned for receiving a second fuel line and operable for permitting the flow of fuel out of the housing member; and
an elongate valve chamber having a proximal end and a distal end, the distal end disposed adjacent the inlet orifice and the outlet orifice, the valve chamber further comprising an axial bore, and an annular seat disposed at the proximal end of the valve chamber; and
a safety valve insert disposed within the axial bore of the valve chamber and operable for interrupting the flow of the fuel from the inlet orifice to the outlet orifice, the safety valve insert comprising:
a piston assembly slidably movable between an open position and a closed position within the axial bore, the piston assembly comprising:
a plunger, including a first end and a second end, the first end configured to be received by the annular seat in the closed position to create a seal between the first end and the annular seat to interrupt the flow of fuel from the inlet orifice to the outlet orifice;
a stem connected to the second end of the plunger, the stem comprising an elongate shaft having a lower end and an upper end, the lower end of the stem operable for connecting to the plunger;
a fusible link connected to the upper end of the stem, the fusible link disposed between the upper end of the stem and the distal end of the valve chamber, the fusible link operable for releasably fixing the piston assembly in the open position and for releasing the piston assembly in response to electrical current passing through the link to a grounding surface;
a connection end formed at an end of the fusible link, the connection end extending through the housing member and operable for connecting to a grounding surface; and
an electrical conductor connected between the housing and the insert to provide an electrical path from the housing to a second end of the fusible link.
2. The safety valve of claim 1 further comprising a biasing member disposed adjacent the second end of the plunger and operable for moving the plunger from the open position to the closed position.
3. The safety valve according to claim 2 wherein the biasing member is a coil spring.
4. The safety valve according to claim 1 , wherein the electrical conductor is an electrically conductive wire connecting the housing member to the safety valve insert, the wire operable for conducting electric current from the housing member to the safety valve insert.
5. The safety valve of claim 1 further comprising a shell disposed adjacent the distal end of the valve chamber and dimensioned for encasing at least a portion of the safety valve insert.
6. The safety valve of claim 5 wherein the shell is electrically non-conductive.
7. The safety valve of claim 1 wherein the fusible link comprises a replaceable cartridge.
8. The safety valve of claim 1 wherein the safety valve insert further comprises a slit disposed in a perimeter section of the plunger and wherein the valve chamber further comprises an elongate guide rod disposed axially along the perimeter of the axial bore, wherein the guide rod and is dimensioned for being slidably moveable within the slit to operatively guide the plunger along the axial bore.
9. The safety valve of 1 wherein the valve chamber further comprises a selectively removable cap disposed within the axial bore adjacent the distal end of the valve chamber, wherein the cap includes an orifice through which at least a portion of the valve insert may extend out of the valve chamber.
10. The safety valve of claim 1 wherein the valve chamber includes a threaded connection end operable for providing a screw-on connection with a similarly threaded shell.
11. A safety valve insert operable with a safety valve, having a housing having an inlet orifice, an outlet orifice, and an axial bore and having an annular seat, for interrupting the flow of fuel through a fuel line, the safety valve insert comprising:
a piston assembly slidably movable between an open position and a closed position within the axial bore, the piston assembly comprising:
a plunger, including a first end and a second end, the first end configured to be received by the annular seat in the closed position to create a seal between the first end and the annular seat to interrupt the flow of fuel from the inlet orifice to the outlet orifice;
a stem connected to the second end of the plunger, the stem comprising an elongate shaft having a lower end and an upper end, the lower end of the stem operable for connecting to the plunger;
a fusible link connected to the upper end of the stem, the fusible link disposed between the upper end of the stem and the distal end of the valve chamber, the fusible link operable for releasably fixing the piston assembly in the open position and for releasing the piston in response to electrical current passing through the link to a grounding surface;
a connection end formed at a first end of the fusible link, the connection end extending through the housing member and operable for connecting to a grounding surface; and
an electrical conductor connected between the housing and the insert to provide an electrical path from the housing to a second end of the fusible link.
12. The safety valve insert of claim 11 further comprising a biasing member disposed adjacent the second end of the plunger and operable for moving the piston assembly from the open position to the closed position.
13. The safety valve insert of claim 12 , wherein the biasing member is a coil spring.
14. The safety valve insert of claim 12 , wherein the biasing member comprises an electrically non-conductive material.
15. The safety valve insert of claim 11 further comprising a shell operable for encasing at least a portion of the safety valve insert.
16. The safety valve insert of claim 15 wherein the shell is electrically non-conductive.
17. The safety valve insert of claim 11 wherein the fusible link comprises a replaceable cartridge.
18. The safety valve insert of claim 11 wherein the safety valve insert further comprises a slit disposed in a perimeter section of the plunger and wherein the valve chamber further comprises an elongate guide rod disposed axially along the perimeter of the axial bore, wherein the guide rod and is dimensioned for being slidably moveable within the slit to operatively guide the plunger along the axial bore.
19. The safety valve insert of claim 18 further comprising a second slit and a second guide rod.
20. A safety valve for interrupting the flow of fuel through a fuel line, the safety valve comprising:
an electrically conductive housing member disposed in a fuel line, the housing member provided with a fluid passage therethrough;
valve means for interrupting fluid passage through the housing member;
triggering means for releasably fixing the valve means in an open position whereby fluid passage through the housing member is permitted and for triggering the movement of the valve means to a closed position where fluid passage is interrupted in response to the presence of electrical current;
grounding means for carrying electrical current from the triggering means to an electrical ground; and
an electrical conductor connected between the housing and the valve means to provide an electrical path from the housing to the grounding means.