Abstract: A reverse acting rupture disc is provided having a laser defined electropolished line-of-weakness recess, and an improved method of forming an electropolished line-of-weakness recess in a reverse acting rupture disc that assures full opening of the disc upon reversal. A rupture disc blank is pre-bulged, final bulged, and then provided with a layer of resist material. A laser is used to remove at least a portion of the layer of resist material corresponding to a desired line-of-weakness recess in the concave face of the bulged rupture disc. The disc is then subjected to an electropolishing operation to remove metal from the lased area of the rupture disc, thereby forming a lustrous polished line-of-weakness recess in the disc of desired configuration and of a predetermined depth that is related to material thickness.

Abstract: A one piece flexible sanitary seal 16 of uniform cross-section is provided for over pressure vent structure that protects a confined space meeting hygienic standards. The seal 16 has an elongated body 38 provided with a central section 40, a C-shaped terminal end 42 having a main lug portion 46 and a secondary lug segment 48 that project away from each other with a cavity 50 therebetween, and a long tail portion 44 cooperating with the central section 40 to present a longitudinally extending angular groove 62. The seal 16 is adapted to be mounted between a vent membrane unit 14 and a frame component 18 of the vent structure. Lug portion 46 and lug segment 48 sealingly engage the inner surface of the vent membrane 14 inboard of a line of weakness therein defined by a series of slots. A rectangular projection 52 extends from the central section 40 in disposition to engage the vent membrane unit 14, outboard of the line of weakness.

Abstract: Apparatus for protecting a confined space having a vent aperture for relief of an overpressure condition and provided with a vent unit having a pressure relief portion normally closing the vent aperture is provided with recloser structure for generally closing off the vent aperture in the event of opening of the pressure relief portion of the vent unit. The recloser structure includes a resilient, flexible, spring steel recloser panel that is normally held in a bent condition out of closing relationship to the vent aperture. Releasable mechanism engages the recloser panel for normally retaining the panel in its open position. An actuator is connected to the releasable mechanism for actuating the latter to release the recloser panel for movement as a function of its inherent resilience into substantially closing relationship to the vent aperture after the relief portion of the vent unit has opened.

Abstract: An oil well completion tool having a tubular assembly defining an elongated main passage is adapted to be connected to a multiple-section tubing string within an oil well casing. A severable plug is mounted in the tubular assembly in normal blocking relationship to the passage. A movable shear cylinder unit has a plug-severing edge operable to sever an entire central segment of the plug from a remaining peripheral portion thereof. Separate hinge structure has an elongated U-shaped leg portion connected to the central segment of the plug. The leg portion of the hinge structure, which undergoes elongation, is operable to retain the severed central segment of the plug in the main passage while allowing the central segment of the plug to bodily shift independent of and in a direction away from the peripheral portion of the plug.

Abstract: An emergency power shutdown management system (EPSMS) comprises a programmable logic controller (PLC), relays coupled to the outputs of the PLC for shutting down electrically operated equipment, and indicators for indicating the status of the EPSMS and the controlled equipment. The PLC receives input signals from a fire control panel including a 2nd alarm signal which is generated after the fire control panel has detected smoke, fire or an explosion with two or more detectors and a system discharge signal which is generated when the fire control panel triggers fire sprinklers or the release of other fire or explosion suppression agents. The PLC also receives an emergency power off (EPO) signal from an EPO switch which is activated to immediately shut down all electrically operated equipment and power distribution units in a protected area.

Abstract: An oil well completion tool having a tubular assembly defining an elongated main passage is adapted to be connected to a multiple-section tubing string within an oil well casing. A severable plug is mounted in the tubular assembly in normal blocking relationship to the passage. A movable shear cylinder unit has a plug-severing edge operable to sever an entire central segment of the plug from a remaining peripheral portion thereof. Separate hinge structure has an elongated U-shaped leg portion connected to the central segment of the plug. The leg portion of the hinge structure, which undergoes elongation, is operable to retain the severed central segment of the plug in the main passage while allowing the central segment of the plug to bodily shift independent of and in a direction away from the peripheral portion of the plug.

Abstract: An activation rupture disc unit is provided that is capable of withstanding a substantially higher back pressure than its burst activation pressure. The unit includes a tubular housing having a fluid passage. Tapered wall structure defines at least a portion of the passage with the fluid outlet thereof being of greater area than the fluid inlet. A rupture disc is carried by the housing and has a central bulged section in fluid-blocking relationship to the passage. A tapered, self-releasing solid plug is positioned in and conforms to the tapered portion of the passage. The plug has a curved surface conforming to and positioned in full supporting relationship to the central section of the rupture disc. The plug is of sufficient mass to prevent rupture of the central section of the disc under a back pressure substantially greater than the activation pressure of the disc.

Abstract: An emergency power shutdown management system (EPSMS) comprises a programmable logic controller (PLC), relays coupled to the outputs of the PLC for shutting down electrically operated equipment, and indicators for indicating the status of the EPSMS and the controlled equipment. The PLC receives input signals from a fire control panel including a 2nd alarm signal which is generated after the fire control panel has detected smoke, fire or an explosion with two or more detectors and a system discharge signal which is generated when the fire control panel triggers fire sprinklers or the release of other fire or explosion suppression agents. The PLC also receives an emergency power off (EPO) signal from an EPO switch which is activated to immediately shut down all electrically operated equipment and power distribution units in a protected area.

Abstract: A one piece flexible sanitary seal 16 of uniform cross-section is provided for over pressure vent structure that protects a confined space meeting hygienic standards. The seal 16 has an elongated body 38 provided with a central section 40, a C-shaped terminal end 42 having a main lug portion 46 and a secondary lug segment 48 that project away from each other with a cavity 50 therebetween, and a long tail portion 44 cooperating with the central section 40 to present a longitudinally extending angular groove 62. The seal 16 is adapted to be mounted between a vent membrane unit 14 and a frame component 18 of the vent structure. Lug portion 46 and lug segment 48 sealingly engage the inner surface of the vent membrane 14 inboard of a line of weakness therein defined by a series of slots. A rectangular projection 52 extends from the central section 40 in disposition to engage the vent membrane unit 14, outboard of the line of weakness.

Abstract: Rectangular or circular vent apparatus for protecting a confined space having a vent aperture for relief of an overpressure condition is provided with each including vent structure having a vent unit adapted to be positioned over the vent aperture in normal closing relationship thereto. Each vent unit preferably includes at least one spring steel panel provided with a movable pressure relief portion having an initial position extending across the vent aperture. A backstop is provided for arresting the degree of movement of the spring steel panel, that absorbs kinetic energy of opening of the spring steel panel, and that assures return of the relief portion of the spring steel panel in substantially its original shape to a selected opening position when a predetermined overpressure is applied against the relief portion of the vent unit. A line of weakness comprising a series of end-to-end slits defines the movable pressure relief portion of each spring steel panel.

Abstract: Apparatus for protecting a confined space having a vent aperture for relief of an overpressure condition and provided with a vent unit having a pressure relief portion normally closing the vent aperture is provided with recloser structure for generally closing off the vent aperture in the event of opening of the pressure relief portion of the vent unit. The recloser structure includes a resilient, flexible, spring steel recloser panel that is normally held in a bent condition out of closing relationship to the vent aperture. Releasable mechanism engages the recloser panel for normally retaining the panel in its open position. An actuator is connected to the releasable mechanism for actuating the latter to release the recloser panel for movement as a function of its inherent resilience into substantially closing relationship to the vent aperture after the relief portion of the vent unit has opened.

Abstract: An emergency power shutdown management system (EPSMS) comprises a programmable logic controller (PLC), relays coupled to the outputs of the PLC for shutting down electrically operated equipment, and indicators for indicating the status of the EPSMS and the controlled equipment. The PLC receives input signals from a fire control panel including a 2nd alarm signal which is generated after the fire control panel has detected smoke, fire or an explosion with two or more detectors and a system discharge signal which is generated when the fire control panel triggers fire sprinklers or the release of other fire or explosion suppression agents. The PLC also receives an emergency power off (EPO) signal from an EPO switch which is activated to immediately shut down all electrically operated equipment and power distribution units in a protected area.

Abstract: Unitary one-piece frameless overpressure vent panel assembly (10) includes a rigid, generally planar primary support member having a central relief opening (26), a rigid, generally planar secondary support member (44) provided with a central relief aperture (46), and a frangible vent panel (30) between the support members in full closing relationship to the relief opening and the aperture. A sealant element (48) may be provided between the vent panel and at least one of the support members in circumscribing relationship to the relief opening or aperture. At least one line of weakness (34) may be provided in the vent panel. A flexible gasket (58) secured to the secondary support member assures a fluid tight seal between the vent panel assembly and the structure defining a protected zone. Alternatively, a knife blade or the like may be provided adjacent the vent panel to effect severing thereof under a predetermined overpressure in lieu of a line of weakness in the panel.

Abstract: A method and apparatus employing a hydrofluorocarbon agent for preventing a large volume of contained flammable fuel from exploding are disclosed. Generally, a method of the present invention comprises detecting a hazardous condition proximate the contained flammable fuel and applying a hydrofluorocarbon agent to an area proximate the fluid within 3–5 seconds of the hazardous condition detection. An apparatus according to the invention comprises a sensing device (24) for detecting the presence of a hazardous condition proximate a quantity of contained flammable fuel (14), and a discharging unit including a pressurizable vessel (16) containing therein the hydrofluorocarbon agent, and a discharge nozzle (20) located proximate the contained flammable fuel (14) and operably coupled with the vessel (16).

Abstract: Non-fragmenting pressure relief apparatus includes at least one circular rupture disc having a central asymmetric bulged section and a peripheral flange portion. A semi-circular line of weakness extends around the periphery of the bulged section and presents a hinge portion between the ends of the line of weakness. A hold-down member for the rupture disc having an inner opening surrounding the bulged section of the disc is provided with a unitary segment that extends into the inner opening of the hold-down member. The spaced end extremities of the line of weakness extend beneath the hold-down member segment. The hinge portion of the disc upon rupture of the disc bends about a fulcrum defined by the outer margin of the hold-down segment, which in conjunction with deflection of the segment of the hold-down member contributes to anti-fragmentation of the disc.

Abstract: A non-fragmenting pressure relief apparatus includes a rupture disc having a central bulged or flat section and a peripheral flange portion. Certain embodiments of the invention have a butterfly shaped element having two wing panels attached to the underside of a rupture disc of the apparatus. A line of weakness of major length extends around the periphery of the central section of a disc and C-shaped end region lines of weakness in the wing panels, which define a hinge portion of the disc therebetween, first converge and then diverge from one another, and connect with the major line of weakness. Application of an overpressure to the rupture disc apparatus causes the entire line of weakness to sever including the end region lines of weakness whereby divergence of the opening force at the hinge portion of the disc prevents separation of the central section of the disc from the peripheral portion of the disc.

Abstract: A metal reverse buckling sanitary rupture disc is provided having a central bulged section in which the convex surface of the bulged section is relatively smooth and of substantially uninterrupted configuration. A small segment region of the central bulged section is strain hardened by plastic deformation causing the segment region to have greater residual stress than the remainder of the central bulged section. When the disc is subjected to an overpressure condition against the convex surface of the bulged section sufficient to effect reversal of the bulged section, such reversal commences at the higher residual stress segment region of the bulged section.

Abstract: This invention relates to a method of converting Halon-based fire suppression systems by substituting HFC 125 for the Halon without the need for changing the in place existing distribution piping. An amount of HFC 125 greater than the amount of Halon utilized in the fire suppression system is provided, which is under a pressure to effect exhaustion of the HFC 125 of the system within a time range exceeding about 10 seconds and up to about 25 seconds and which meets the standard fire extinguishing requirements for Class A and Class B fires. An existing fire suppression system is analyzed for flow characteristics to find TD of that system. The greater quantity C+ of HFC 125 required for the retrofitted system is determined by the formula C+=((TD?10)/(2×TCRIT)?TD×100) wherein TCRIT=0.Y×(TD?10)/(C+/100))+TD. The method may also be utilized to determine the amount of HFC 125 required for the retrofitted fire suppression system.

Abstract: A relatively low pressure inert gas hazard suppression system (20) is provided which is designed to protect a room (22) or the like from the effects of fire or other hazard. The system (20) includes a plurality of pressurized inert gas cylinders (24) each equipped with a valve unit (26); each valve unit (26) is in turn coupled via a conduit (28) to a delivery manifold (30). The respective valve units (26) are operable to deliver gas from the cylinders (24) at a generally constant pressure (usually around 10-100 bar) throughout a substantial portion of the time of gas delivery, to thereby provide effective hazard suppression without the need for expensive high-pressure gas handling and distribution hardware and a reduction in room venting area due to lower room over-pressurization. Each valve unit (26) has a valve body (48) and a shiftable piston-type sealing member (56).

Abstract: An improved dump valve assembly (22) is provided for use as a part of an elongated, sectionalized, tubular downhole pipe string (18). The assembly (22) includes a tubular pipe section (24) having endmost threading (34, 38) and a rupture disc fitting (26); the fitting (26) includes a metallic, preferably concavo-convex disc (50) with preformed lines of weakness (52, 54) on one face thereof. The section (24) is interconnected between a pair of lower pipe sections (20a, 20b). In operation when it is desired to elevate the string (18) from the well, the fluid within the string (18) is pressurized sufficiently to rupture the disc (50), thereby allowing fluid within the string (18) to drain. The string (18) and other well components can then be removed from the well without contamination owing to spillage from the tubular string (18).