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

Description:
BACKGROUND OF THE INVENTION 
     This invention relates to fluid control valves and more particularly to a high temperature fire hazard fluid release valve. 
     1. Field of the Invention 
     Relief valves for protecting equipment and piping under pressure 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 connected with 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 a closed fluid flow position to an open 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 valve in a 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 and responsive to the fluid being monitored by a heat fusible plug maintaining a fluid pressure responsive relief valve which monitors the fluid pressure, whether flowing or stopped, and releases the same in responsive to excessive fluid pressure but has the additional feature of a heat fusible plug maintaining a pressure responsive collapsible pin in a valve closed or open position in accordance with the type of valve being used whether inline permitting fluid flow or a right angle valve preventing fluid flow. 
     I am not aware of any prior art valve disclosing this pressure responsive, heat fusible plug type relief valve. 
     BRIEF SUMMARY OF THE INVENTION 
     A valve body having bolt flanges for connection with a pipeline forms a fluid passageway between the bolt flange ends. A body bore inline with the inlet port intersects the fluid passageway and forms a shoulder and sleeve-like valve seat mating and mismating with a piston type valve, having a piston rod slideably projecting axially outward through a central bore in a valve bonnet head. A pressure responsive collapsible pin projects axially outward from the end of the piston rod, opposite the piston and is slidable in a bore in a plate. The plate is supported in parallel spaced relation with the valve bonnet by a plurality of bolts forming a pin cage means. Sleeves surrounding the posts maintain the plate in spaced relation with the bonnet head and an axial threaded bore in the plate receives a bushing having an axial bore slideably surrounding the other end portion of the collapsible pin. An axial threaded opening in the plate bushing is filled with a heat fusible alloy, such as babbitt. 
     The principal object of this invention is to provide a pressure control 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 an end portion of the collapsible pin for sliding movement outwardly of the valve and allowing a valve to open for releasing fluid 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 closed position; and, 
     FIG. 3 is a view similar to FIG. 2, illustrating the valve in open position. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The reference numeral  10  indicates the valve as a whole having a body  12  and an inlet bolt flange  14  normal to an outlet bolt flange  15  forming an inlet port  16  and exhaust port  18 , respectively, and a fluid passageway  20  between the inlet and outlet ports. The wall forming the inward limit of the inlet port  16  defines a valve seat  22  for sealing with a valve and closing the fluid passageway  20  as presently explained. The valve body is counterbored inline with the inlet port  16 , as at  24 , forming a shoulder  25  at the inward limit of the valve seat  22 . The end of the bore  24  opposite the inlet port is closed by a valve head or bonnet  26  having a flanged end  28  secured to the valve body by bolts  30 . The bonnet  26  is centrally bored, as at  32 , for receiving the stem  34  of valve means such as a piston valve  36 . The piston valve is cooperatively received by the valve seat surface  22  and is provided with an annular outstanding flange  38  for contact with the shoulder  25 . O-rings  39  seal the bonnet to the valve body and piston rod to the valve bonnet as well as the piston with the valve seat surface  22 . 
     The pin cage means  40  comprises a collapsible pin  42  having a first end portion supported in a socket  44  in the end of the piston rod  34  projecting outwardly of the valve bonnet  26 . The other or second end portion 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  28  by plurality three (3), in the example shown, of posts  52  and nuts  53  and secured at one end to the valve bonnet flange  28  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 grooved or screw threaded, as at  56 , communicating with the bore  46  containing the second 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 inserted into the threaded 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  59  embedded in the plug and interposed between the plug and the adjacent end of the pin  42  and initially fail in response to heat approaching the melting point of the circumference of the plug  58  thus allowing fluid pressure to move the piston  36  and open the fluid passageway and simultaneously eject the plug  58  by the adjacent end portion of the pin  42  in contact with the disc  59  and sliding through the bore  46 . A conventional proximity fuse  35  is mounted on the bonnet to indicate opening action of the valve  10 . 
     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  36  in flow passageway closed position against fluid under pressure. In the event of a fire and heat approaching the melting point of the fusible plug  58  the plug threads at least partially melts and the fluid pressure axially moves the piston off seat and axially moves the pin  42  ejecting the fusible plug  58  thus opening the fluid passageway  20  and exhausting fluid downstream. 
     The valve may be placed back in operation by manually moving the piston  36  to its fluid passageway closed 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 . 
     A second feature of the valve is monitoring excess fluid pressure by the collapsible pin  42 . In the event the fluid pressure on the piston  36  reaches a predetermined value, the fluid pressure moves the piston off seat collapsing the pin  42  to the dotted line position of FIG. 3, thus opening the valve and exhausting fluid downstream. 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.