Abstract:
A fluid pressure and heat sensitive flow control valve interposed in a flow line includes a collapsible pin, normally maintaining the valve open, which collapses to close the valve in response to fluid pressure above a predetermined limit and includes a fusible plug which melts in event of a fire, releasing the pin to allow fluid pressure to close the valve.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     Not applicable. 
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not applicable 
     BACKGROUND OF THE INVENTION 
     This invention relates to fluid control valves and more particularly to a high temperature fire hazard shutdown valve for interrupting fluid flow. 
     1. Field of the Invention 
     Relief valves or emergency shutdown valves for protecting equipment and piping under greater than a predetermined value for releasing or stopping the flow of fluid are well known. However, there is a need for a heat responsive valve to be interposed in a fluid conducting line which is responsive to excessive heat such as, heat generated by a fire in which a heat responsive element forms a fuse for moving a valve from an open fluid flow position to a closed position or vice versa. 
     2. Description of the Prior Art 
     The prior art generally reveals a plurality of heat responsive valves, commonly referred to as sprinkler valve heads, which are connected with a fluid fire retardant, usually water, which is released to control the fire in response to a predetermined temperature melting a fusible link maintaining the sprinkler head in valve closed position which when melted by excessive heat allows fluid to be sprayed into a predetermined area for controlling fires. 
     This invention provides a valve which controls the flow of fluid by allowing fluid flow therethrough in which a heat fusible plug maintains a pressure responsive collapsible pin relief valve monitoring fluid flowing through the valve and interrupts the flow by collapse of the pin in response to excessive fluid pressure with the additional feature of the heat fusible plug melting as a result of a fire and releasing one end portion of the pressure responsive collapsible pin, thus allowing fluid pressure to close the valve flow passageway. 
     I am not aware of any prior art valve disclosing this fluid pressure responsive, fusible plug type emergency shut-down valve. 
     BRIEF SUMMARY OF THE INVENTION 
     A valve body having spaced-apart bolt flanges for inline connection with a pipeline is provided with a flow passageway between the bolt flange ends. A transverse bore, open to one side of the body, intersects the fluid passageway and forms a shoulder for receiving a sleeve-like valve seat mating and sealing with a piston type valve, having a piston rod slideably projecting axially outward of a central bore in a bonnet head. A pressure responsive collapsible pin projects axially outward from the end of the piston rod, opposite the piston and is slideably received by a bore in a plate parallel with the valve bonnet and supported in spaced relation there-with by a plurality of bolts forming a cage means  40 . Sleeves surrounding the posts maintain the plate in spaced relation with the bonnet head and an axial threaded bore in the plate receives a plate bushing having an axial bore slideably surrounding the other end portion of the collapsible pin. An axial opening in the plate bushing opposite the collapsible pin is filled with a heat fusible alloy, such as babbitt. 
     The principal object of this invention is to provide a fluid pressure control emergency shutdown or relief valve having a fuse plug maintaining a pressure responsive collapsible pin holding a valve in a seated or unseated position which further includes a heat fusible plug which releases one end portion of the collapsible pin in response to a predetermined temperature for sliding movement outwardly of the valve and allowing a valve to seat or unseat for permitting or stopping fluid flow through the valve. 
    
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
     FIG. 1 is a top view; 
     FIG. 2 is a vertical cross sectional view taken substantially along the line  2 — 2  of FIG. 1, illustrating the valve in open position; and, 
     FIG. 3 is a view similar to FIG. 2, illustrating the valve in closed position. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The reference numeral  10  indicates the valve as a whole comprising a valve body  12  having bolt flange ends  14  adapted to be interposed in a fluid conductor, not shown. 
     The bolt flange ends  14  are provided with inlet and outlet ports  16  and  18 , respectively, forming a fluid passageway way  20  through the valve. 
     A partition transversely intersects the fluid passageway and is centrally bored and threaded as at  22  forming a valve seat shoulder for receiving a valve seat body  24  having a central opening forming a cylindrical valve seat  25 . The valve body is counterbored on opposite sides of the valve seat, as at  26  and  28 . The inlet and outlet port bores being respectively angled toward the innermost end of the counterbore  28  and the downstream side of the valve seat  24 . The counterbore  26  is closed by a centrally bored valve bonnet  30  having a flanged end  32  opposite the valve seat. 
     Valve means such as a piston valve  34  having a diameter cooperatively received slideably by the valve seat sealing surface  25  and having a flanged end  35  opposite a stem or piston rod  36  is axially disposed in the valve counterbores  26  and  28  with the rod  36  slideably projecting through the central bore  38  of the valve bonnet. The piston valve  34  is normally maintained off seat and the fluid passageway  20  open by a collapsible pin in a cage means  40  connected with the valve body bonnet. 
     O-rings  39  seal the valve seat  24  and bonnet  30  with the body  12  and the piston  34  and piston rod  36  with the valve seat  24  and bonnet  30 , respectively. 
     The pin cage means  40  comprises a collapsible pin  42  having one end portion supported in a socket  44  in the end of the piston rod  36  projecting outwardly of the valve bonnet  30 . The other end of the collapsible pin is nested by a central bore  46  in a plate bushing  48  threadedly received axially by a plate  50  maintained in spaced relation with the valve bonnet flange  32  by plurality three (3), in the example shown, of posts  52  and nuts  53  and secured at one end to the valve bonnet flange  32  with a like plurality of sleeve spacers  54  around the posts interposed between the valve bonnet and the plate  50 . 
     The bushing  48  is similarly centrally bored and threaded, as at  56 , communicating with the bore  46  containing the end portion of the collapsible pin  42 . The bore  56  cooperatively receives a fusible plug  58  formed from a relatively low temperature melting point alloy, such as babbitt, for the purpose presently explained. 
     The plug  58  may be poured, as molten metal into the threaded bore  56  or formed in a separate mold and screwed into the bore  56 . In either event the cooperating threads, on the inner periphery of the bore  56  and periphery of the plug  58  are believed necessary to insure a positive contact between the plug  58  and bore  56  sufficient to form a stop with a hard metal disc embedded in the plug and interposed between the plug and adjacent end of the pin  42  and initially fail in response to heat approaching the melting point of the plug  58  periphery thus allowing fluid pressure to move the piston  34  and close the fluid passageway and simultaneously eject the plug  58  by the adjacent end portion of the pin  42  sliding through the bore  46 . 
     OPERATION 
     In operation, assuming the valve  10  has been assembled and installed as described in a fluid conductor. In the position illustrated by FIG. 2, the collapsible pin  42  maintains the piston valve  34  in flow passageway open position with fluid under pressure flowing through the valve  10 . In the event of a fire and heat approaching the melting point of the fusible plug  58  the plug threads at least partially melt and the fluid pressure moves the pin  42  and the piston valve  34  to a seated position with the valve seat  24  (FIG. 3) thus closing the fluid passageway and shutting down the fluid system controlled by the valve. 
     The valve may be placed back in operation by manually moving the piston  34  to its fluid passageway open position, and positioning the collapsible pin  42 , in the position illustrated by FIG.  2 . Installing a new fusible plug  58 , not shown, in the threaded socket  56  of the plate bushing  48  and thereafter allowing fluid flow through the passageway  20 . 
     A second feature of the valve is monitoring excess fluid pressure by the collapsible pin  42 . In the event the fluid flowing through the passageway  20  reaches a predetermined value, fluid pressure moves the piston toward its seat collapsing the pin  42  to the dotted line position of FIG. 3, thus closing the valve and shutting down the fluid system. After the excess pressure problem has been corrected the collapsible pin may be replaced by installing a new pin  42 , not shown, after removing the collapsed pin by unscrewing the plate bushing  48  from the plate  50 , placing the replacement collapsible pin in the piston rod socket rod  44  and replacing the plate bushing  48  so its socket  46  surrounds the other end portion of the new collapsible pin. 
     Obviously the invention is susceptible to changes or alterations without defeating its practicability. Therefore, I do not wish to be confined to the preferred embodiment(s) shown in the drawing(s) and described herein.